Prostate cancer

From Wikipedia, the free encyclopedia

Jump to: navigation, search
Prostate cancer
Classification and external resources
ICD-10C61.
ICD-9185
OMIM176807
DiseasesDB10780
MedlinePlus000380
eMedicineradio/574
MeSHD011471

Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. The cancer cells may metastasize (spread) from the prostate to other parts of the body, particularly the bones and lymph nodes. Prostate cancer may cause pain, difficulty in urinating, problems during sexual intercourse, or erectile dysfunction. Other symptoms can potentially develop during later stages of the disease.

Rates of detection of prostate cancers vary widely across the world, with South and East Asia detecting less frequently than in Europe, and especially the United States.[1] Prostate cancer tends to develop in men over the age of fifty and although it is one of the most prevalent types of cancer in men, many never have symptoms, undergo no therapy, and eventually die of other causes. This is because cancer of the prostate is, in most cases, slow-growing, symptom free and men with the condition often die of causes unrelated to the prostate cancer, such as heart/circulatory disease, pneumonia, other unconnected cancers, or old age. Many factors, including genetics and diet, have been implicated in the development of prostate cancer. The presence of prostate cancer may be indicated by symptoms, physical examination, prostate specific antigen (PSA), or biopsy. There is controversy about the accuracy of the PSA test and the value of screening. Suspected prostate cancer is typically confirmed by taking a biopsy of the prostate and examining it under a microscope. Further tests, such as CT scans and bone scans, may be performed to determine whether prostate cancer has spread.

Treatment options for prostate cancer with intent to cure are primarily surgery and radiation therapy. Other treatments such as hormonal therapy, chemotherapy, proton therapy, cryosurgery, high intensity focused ultrasound (HIFU) also exist depending on the clinical scenario and desired outcome.

The age and underlying health of the man, the extent of metastasis, appearance under the microscope, and response of the cancer to initial treatment are important in determining the outcome of the disease. The decision whether or not to treat localized prostate cancer (a tumor that is contained within the prostate) with curative intent is a patient trade-off between the expected beneficial and harmful effects in terms of patient survival and quality of life.

Contents

[edit] Classification

Prostatelead.jpg

The prostate is a part of the male reproductive organ that helps make and store seminal fluid. In adult men, a typical prostate is about three centimeters long and weighs about twenty grams.[2] It is located in the pelvis, under the urinary bladder and in front of the rectum. The prostate surrounds part of the urethra, the tube that carries urine from the bladder during urination and semen during ejaculation.[3] Because of its location, prostate diseases often affect urination, ejaculation, and rarely defecation. The prostate contains many small glands which make about twenty percent of the fluid constituting semen.[4] In prostate cancer, the cells of these prostate glands mutate into cancer cells. The prostate glands require male hormones, known as androgens, to work properly. Androgens include testosterone, which is made in the testes; dehydroepiandrosterone, made in the adrenal glands; and dihydrotestosterone, which is converted from testosterone within the prostate itself. Androgens are also responsible for secondary sex characteristics such as facial hair and increased muscle mass.

An important part of evaluating prostate cancer is determining the stage, or how far the cancer has spread. Knowing the stage helps define prognosis and is useful when selecting therapies. The most common system is the four-stage TNM system (abbreviated from Tumor/Nodes/Metastases). Its components include the size of the tumor, the number of involved lymph nodes, and the presence of any other metastases.

The most important distinction made by any staging system is whether or not the cancer is still confined to the prostate. In the TNM system, clinical T1 and T2 cancers are found only in the prostate, while T3 and T4 cancers have spread elsewhere. Several tests can be used to look for evidence of spread. These include computed tomography to evaluate spread within the pelvis, bone scans to look for spread to the bones, and endorectal coil magnetic resonance imaging to closely evaluate the prostatic capsule and the seminal vesicles. Bone scans should reveal osteoblastic appearance due to increased bone density in the areas of bone metastasis—opposite to what is found in many other cancers that metastasize.

Computed tomography (CT) and magnetic resonance imaging (MRI) currently do not add any significant information in the assessment of possible lymph node metastases in patients with prostate cancer according to a meta-analysis.[5] The sensitivity of CT was 42% and specificity of CT was 82%. The sensitivity of MRI was 39% and the specificity of MRI was 82%. For patients at similar risk to those in this study (17% had positive pelvic lymph nodes in the CT studies and 30% had positive pelvic lymph nodes in the MRI studies), this leads to a positive predictive value (PPV) of 32.3% with CT, 48.1% with MRI, and negative predictive value (NPV) of 87.3% with CT, 75.8% with MRI.

After a prostate biopsy, a pathologist looks at the samples under a microscope. If cancer is present, the pathologist reports the grade of the tumor. The grade tells how much the tumor tissue differs from normal prostate tissue and suggests how fast the tumor is likely to grow. The Gleason system is used to grade prostate tumors from 2 to 10, where a Gleason score of 10 indicates the most abnormalities. The pathologist assigns a number from 1 to 5 for the most common pattern observed under the microscope, then does the same for the second-most-common pattern. The sum of these two numbers is the Gleason score. The Whitmore-Jewett stage is another method sometimes used. Proper grading of the tumor is critical, since the grade of the tumor is one of the major factors used to determine the treatment recommendation.[citation needed]

[edit] Signs and symptoms

Early prostate cancer usually causes no symptoms. Often it is diagnosed during the workup for an elevated PSA noticed during a routine checkup. It's highly advised to avoid sexual intercourse for 3 days prior to a PSA test because that does affect the outcome of the test. Sometimes, however, prostate cancer does cause symptoms, often similar to those of diseases such as benign prostatic hypertrophy. These include frequent urination, increased urination at night, difficulty starting and maintaining a steady stream of urine, blood in the urine, and painful urination. Prostate cancer is associated with urinary dysfunction as the prostate gland surrounds the prostatic urethra. Changes within the gland, therefore, directly affect urinary function. Because the vas deferens deposits seminal fluid into the prostatic urethra, and secretions from the prostate gland itself are included in semen content, prostate cancer may also cause problems with sexual function and performance, such as difficulty achieving erection or painful ejaculation.[6]

Advanced prostate cancer can spread to other parts of the body, possibly causing additional symptoms. The most common symptom is bone pain, often in the vertebrae (bones of the spine), pelvis, or ribs. Spread of cancer into other bones such as the femur is usually to the proximal part of the bone. Prostate cancer in the spine can also compress the spinal cord, causing leg weakness and urinary and fecal incontinence.[7]

[edit] Causes

The specific causes of prostate cancer remain unknown.[8] A man's risk of developing prostate cancer is related to his age, genetics, race, diet, lifestyle, medications, and other factors. The primary risk factor is age. Prostate cancer is uncommon in men younger than 45, but becomes more common with advancing age. The average age at the time of diagnosis is 70.[9] However, many men never know they have prostate cancer. Autopsy studies of Chinese, German, Israeli, Jamaican, Swedish, and Ugandan men who died of other causes have found prostate cancer in thirty percent of men in their 50s, and in eighty percent of men in their 70s.[10] In the year 2005 in the United States, there were an estimated 230,000 new cases of prostate cancer and 30,000 deaths due to prostate cancer.[11]

[edit] Genetics

A man's genetic background contributes to his risk of developing prostate cancer. This is suggested by an increased incidence of prostate cancer found in certain racial groups, in identical twins of men with prostate cancer, and in men with certain genes. In the United States, prostate cancer more commonly affects black men than white or Hispanic men, and is also more deadly in black men.[12] Men who have a brother or father with prostate cancer have twice the usual risk of developing prostate cancer.[13] Studies of twins in Scandinavia suggest that forty percent of prostate cancer risk can be explained by inherited factors.[14] However, no single gene is responsible for prostate cancer; many different genes have been implicated. Two genes (BRCA1 and BRCA2) that are important risk factors for ovarian cancer and breast cancer in women have also been implicated in prostate cancer.[15]

[edit] Diet

Dietary amounts of certain foods, vitamins, and minerals can contribute to prostate cancer risk. Dietary factors that may decrease prostate cancer risk include the mineral selenium[16][17]. A study in 2007 cast doubt on the effectiveness of lycopene (found in tomatoes) in reducing the risk of prostate cancer.[18] Lower blood levels of vitamin D also may increase the risk of developing prostate cancer. This may be linked to lower exposure to ultraviolet (UV) light, since UV light exposure can increase vitamin D in the body.[19]

A large study has implicated dairy, specifically low-fat milk and other dairy products to which vitamin A palmitate has been added. This form of synthetic vitamin A has been linked to prostate cancer because it reacts with zinc and protein to form an unabsorbable complex.[citation needed]

Folic acid supplements have recently been linked to an increase in risk of developing prostate cancer.[20] Recently a ten year research study led by University of Southern California researchers showed that men who took daily folic acid supplements of 1 mg were three times more likely to be diagnosed with prostate cancer than men who took a placebo.[20] Folate plays a complex role in prostate cancer and folic acid supplements have a different effect on prostate cancer than folate naturally found in foods.[20] The supplement form, folic acid, is more bioavailable in the body compared with dietary sources of folate.[20]

Folic acid used in fortified foods is a synthetic form called pteroylmonoglutamate. It is in its oxidized state and contains only one conjugated glutamate residue. Folic acid therefore enters via a different carrier system than naturally occurring folate and this may have different effects on folate binding proteins and its transporters.

[edit] Medication exposure

There are also some links between prostate cancer and medications, medical procedures, and medical conditions. Daily use of anti-inflammatory medicines such as aspirin, ibuprofen, or naproxen may decrease prostate cancer risk.[21] Use of the cholesterol-lowering drugs known as the statins may also decrease prostate cancer risk.[22] Infection or inflammation of the prostate (prostatitis) may increase the chance for prostate cancer. In particular, infection with the sexually transmitted infections chlamydia, gonorrhea, or syphilis seems to increase risk.[23] Finally, obesity[24] and elevated blood levels of testosterone[25] may increase the risk for prostate cancer.

Research released in May 2007, found that US war veterans who had been exposed to Agent Orange had a 48% increased risk of prostate cancer recurrence following surgery.[26]

[edit] Potential viral cause

In 2006, researchers associated a previously unknown retrovirus, Xenotropic MuLV-related virus or XMRV, with human prostate tumors.[27] Subsequent reports on the virus have been contradictory. A group of US researchers found XMRV protein expression in human prostate tumors,[28] while German scientists failed to find XMRV-specific antibodies or XMRV-specific nucleic acid sequences in prostate cancer samples.[29]

[edit] Pathophysiology

When normal cells are damaged beyond repair, they are eliminated by apoptosis. Cancer cells avoid apoptosis and continue to multiply in an unregulated manner.

Prostate cancer is classified as an adenocarcinoma, or glandular cancer, that begins when normal semen-secreting prostate gland cells mutate into cancer cells. The region of prostate gland where the adenocarcinoma is most common is the peripheral zone. Initially, small clumps of cancer cells remain confined to otherwise normal prostate glands, a condition known as carcinoma in situ or prostatic intraepithelial neoplasia (PIN). Although there is no proof that PIN is a cancer precursor, it is closely associated with cancer. Over time, these cancer cells begin to multiply and spread to the surrounding prostate tissue (the stroma) forming a tumor. Eventually, the tumor may grow large enough to invade nearby organs such as the seminal vesicles or the rectum, or the tumor cells may develop the ability to travel in the bloodstream and lymphatic system. Prostate cancer is considered a malignant tumor because it is a mass of cells that can invade other parts of the body. This invasion of other organs is called metastasis. Prostate cancer most commonly metastasizes to the bones, lymph nodes, rectum, and bladder.

[edit] Diagnosis

The only test that can fully confirm the diagnosis of prostate cancer is a biopsy, the removal of small pieces of the prostate for microscopic examination. However, prior to a biopsy, several other tools may be used to gather more information about the prostate and the urinary tract. Cystoscopy shows the urinary tract from inside the bladder, using a thin, flexible camera tube inserted down the urethra. Transrectal ultrasonography creates a picture of the prostate using sound waves from a probe in the rectum.

[edit] Biopsy

If cancer is suspected, a biopsy is offered. During a biopsy a urologist or radiologist obtains tissue samples from the prostate via the rectum. A biopsy gun inserts and removes special hollow-core needles (usually three to six on each side of the prostate) in less than a second. Prostate biopsies are routinely done on an outpatient basis and rarely require hospitalization. Fifty-five percent of men report discomfort during prostate biopsy.[30]

[edit] Gleason score

The tissue samples are then examined under a microscope to determine whether cancer cells are present, and to evaluate the microscopic features (or Gleason score) of any cancer found.

[edit] Tumor markers

Tissue samples can be stained for the presence of PSA and other tumor markers in order to determine the origin of maligant cells that have metastasized.[31]

[edit] Diagnostic tools under investigation

At present, an active area of research involves non-invasive methods of prostate tumor detection. Adenoviruses modified to transfect tumor cells with harmless yet distinct genes (such as luciferase) have proven capable of early detection. So far, however, this area of research has been tested only in animal and LNCaP models.[32]

[edit] PCA3

Another potential non-invasive method of early prostate tumor detection is through a molecular test that detects the presence of cell-associated PCA3 mRNA in urine. PCA3 mRNA is expressed almost exclusively by prostate cells and has been shown to be highly over-expressed in prostate cancer cells. PCA3 is not a replacement for PSA but an additional tool to help decide whether, in men suspected of having prostate cancer, a biopsy is really needed. The higher the expression of PCA3 in urine, the greater the likelihood of a positive biopsy, i.e., the presence of cancer cells in the prostate.

[edit] Early prostate cancer

It was reported in April 2007 that a new blood test for early prostate cancer antigen-2 (EPCA-2) that may alert men if they have prostate cancer and how aggressive it will be is being researched.[33][34]

[edit] Prostate mapping

Prostate mapping is a method of diagnosis that may be accurate in determining the precise location and aggressiveness of a tumor. It uses a combination of multi-sequence MRI imaging techniques and a template-guided biopsy system, and involves taking multiple biopsies through the skin that lies in front of the rectum rather than through the rectum itself. The procedure is carried out under general anesthetic.[35]

[edit] Prostasomes

Epithelial cells of the prostate secrete prostasomes as well as PSA. Prostasomes are membrane–surrounded, prostate-derived organelles that appear extracellularly, and one of their physiological functions is to protect the sperm from attacks by the female immune system. Cancerous prostate cells continue to synthesize and secrete prostasomes, and may be shielded against immunological attacks by these prostasomes. Research of several aspects of prostasomal involvement in prostate cancer has been performed.[36]

[edit] Prevention

[edit] Food, vitamins and medication

Evidence from epidemiological studies supports a possible protective role in reducing prostate cancer for dietary selenium, vitamin E, lycopene, and soy foods. High plasma levels of Vitamin D may also have a protective effect.[37] Estrogens from fermented soybeans and other plant sources (called phytoestrogens) may also help prevent prostate cancer.[38] The selective estrogen receptor modulator drug toremifene has shown promise in early trials.[39][40] Two medications which block the conversion of testosterone to dihydrotestosterone, finasteride[41] and dutasteride,[42] have also shown some promise. The use of these medications for primary prevention is still in the testing phase, and they are not widely used for this purpose. The initial problem with these medications is that they may preferentially block the development of lower-grade prostate tumors, leading to a relatively greater chance of higher grade cancers, and negating any overall survival improvement. More recent research found that finasteride did not increase the percentage of higher grade cancers. A 2008 study update found that finasteride reduces the incidence of prostate cancer by 30%. In the original study it turns that that the smaller prostate caused by finasteride means that a doctor is more likely to hit upon cancer nests and more likely to find aggressive-looking cells. Most of the men in the study who had cancer — aggressive or not — chose to be treated and many had their prostates removed. A pathologist then carefully examined every one of those 500 prostates and compared the kinds of cancers found at surgery to those initially diagnosed at biopsy. Finasteride did not increase the risk of High-Grade prostate cancer.[43][43]

Green tea may be protective (due to its polyphenol content),[44] although the most comprehensive clinical study indicates that it has no protective effect.[45] A 2006 study of green tea derivatives demonstrated promising prostate cancer prevention in patients at high risk for the disease.[46] Recent research published in the Journal of the National Cancer Institute suggests that taking multivitamins more than seven times a week can increase the risks of contracting the disease.[47][48] This research was unable to highlight the exact vitamins responsible for this increase (almost double), although they suggest that vitamin A, vitamin E and beta-carotene may lie at its heart. It is advised that those taking multivitamins never exceed the stated daily dose on the label. Scientists recommend a healthy, well balanced diet rich in fiber, and to reduce intake of meat.[citation needed] A 2007 study published in the Journal of the National Cancer Institute found that men eating cauliflower, broccoli, or one of the other cruciferous vegetables, more than once a week were 40% less likely to develop prostate cancer than men who rarely ate those vegetables.[49][50] The phytochemicals indole-3-carbinol and diindolylmethane, found in cruciferous vegetables, has antiandrogenic and immune modulating properties.[51][52]

A comprehensive worldwide report Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective compiled by World Cancer Research Fund and American Institute for Cancer Research reports that there is significant relation between lifestyle (including food consumption) and cancer prevention.

[edit] Ejaculation frequency

More frequent ejaculation also may decrease a man's risk of prostate cancer. One study showed that men who ejaculated five times a week in their 20s had a decreased rate of prostate cancer, though other studies have shown no benefit.[53][54] The results contradict those of previous studies, which have suggested that having had many sexual partners, or a high frequency of sexual activity, increases the risk of prostate cancer by up to 40 percent. The key difference is that these earlier studies defined sexual activity as sexual intercourse, whereas this study focused on the number of ejaculations, whether or not intercourse was involved.[55] Another study completed in 2004 reported that "Most categories of ejaculation frequency were unrelated to risk of prostate cancer. However, high ejaculation frequency was related to decreased risk of total prostate cancer." The report abstract concluded, "Our results suggest that ejaculation frequency is not related to increased risk of prostate cancer." [56] A 2008 study showed that men who engaged in frequent masturbation, of about two to seven times a week, at the ages of 20s and 30s, had a higher rate of prostate cancer, while men who engaged in frequent masturbation, once a week, at the age of 50s had a lower rate.[57]

[edit] Oils and fatty acids

In experimental models using mice have been tested, dietary and serum omega-6 polyunsaturated fatty acids (PUFAs) increased prostate tumor growth,and has sped up histopathological progression, and decreased survival, while the omega-3 fatty acids, in the same situation, had the opposite, beneficial effect.[58]

Men with higher serum levels of the short-chain omega-6 fatty acid linoleic acid have higher rates of prostate cancer.[59] However, men with high serum linoleic acid, but not palmitic, can reduce the risk of prostate cancer by taking tocopherol supplementation.[60]

Men with elevated levels of long-chain omega-3 fatty acids (EPA and DHA) had lowered incidence.[59]

A long-term study reports that "blood levels of trans fatty acids, in particular trans fats resulting from the hydrogenation of vegetable oils, are associated with an increased prostate cancer risk."[61]

Some researchers have indicated that serum myristic acid[60][62] and palmitic acid[62] and dietary myristic[63] and palmitic[63] saturated fatty acids and serum palmitic combined with alpha-tocopherol supplementation[60] are associated with increased risk of prostate cancer in a dose-dependent manner. Serum association of these and other saturated fatty acids was also investigated by another study.[62]

The American Dietetic Association and Dieticians of Canada report a decreased incidence of prostate cancer for those following a vegetarian diet.[64]

[edit] Screening

Prostate cancer screening is an attempt to find unsuspected cancers. Screening tests may lead to more specific follow-up tests such as a biopsy, where small cores of the prostate are removed for closer study. Prostate cancer screening options include the digital rectal exam and the prostate-specific antigen (PSA) blood test. Screening for prostate cancer is controversial because it is expensive and is not at all clear whether the benefits of screening outweigh the risks of follow-up diagnostic tests and cancer treatments and the unnecessary worry for the patient that often ensues.

Prostate cancer is usually a slow-growing cancer, very common among older men. In fact, most prostate cancers never grow to the point where they cause symptoms, and most men with prostate cancer die of other causes before prostate cancer has an impact on their lives. The PSA screening test may detect these small cancers that would never become life-threatening. Doing the PSA test in these men may lead to overdiagnosis, including additional testing and treatment. Follow-up tests, such as prostate biopsy, may cause pain, bleeding and infection. Prostate cancer treatments may cause urinary incontinence and erectile dysfunction. A large randomized study in which 76,000 men were randomized to receive either PSA screening or conventional care found that more men that underwent PSA screening were diagnosed with prostate cancer, but that there was no difference in mortality between the two groups.[65]

The results from two of the largest randomized trials regarding the efficacy of screening have now been published.[66] In one of these trials, the death rate from prostate cancer was actually higher in the group that had total screening compared to the control group that had only normal rates of screening. The other showed some benefit from screening, but the reduction in deaths was minor compared to the level of intervention needed to prevent it.

[edit] Management

Treatment for prostate cancer may involve active surveillance, surgery, radiation therapy including brachytherapy (prostate brachytherapy) and external beam radiation therapy, High-intensity focused ultrasound (HIFU), chemotherapy, cryosurgery, hormonal therapy, or some combination. Which option is best depends on the stage of the disease, the Gleason score, and the PSA level. Other important factors are the man's age, his general health, and his feelings about potential treatments and their possible side-effects. Because all treatments can have significant side-effects, such as erectile dysfunction and urinary incontinence, treatment discussions often focus on balancing the goals of therapy with the risks of lifestyle alterations.

The selection of treatment options may be a complex decision involving many factors. For example, radical prostatectomy after primary radiation failure is a very technically challenging surgery and may not be an option.[67] This may enter into the treatment decision.

If the cancer has spread beyond the prostate, treatment options significantly change, so most doctors that treat prostate cancer use a variety of nomograms to predict the probability of spread. Treatment by watchful waiting/active surveillance, HIFU, external beam radiation therapy, brachytherapy, cryosurgery, and surgery are, in general, offered to men whose cancer remains within the prostate. Hormonal therapy and chemotherapy are often reserved for disease that has spread beyond the prostate. However, there are exceptions: radiation therapy may be used for some advanced tumors, and hormonal therapy is used for some early stage tumors. Cryotherapy (the process of freezing the tumor), hormonal therapy, and chemotherapy may also be offered if initial treatment fails and the cancer progresses.[68]

[edit] Prognosis

Prostate cancer rates are higher and prognosis poorer in developed countries than the rest of the world. Many of the risk factors for prostate cancer are more prevalent in the developed world, including longer life expectancy and diets high in red meat and reduced-fat dairy products to which vitamin A palmitate has been added.[69] (People that consume larger amounts of meat and dairy also tend to consume fewer portions of fruits and vegetables. It is not currently clear whether both of these factors, or just one of them, contribute to the occurrence of prostate cancer.[70]) Also, where there is more access to screening programs, there is a higher detection rate. Prostate cancer is the ninth-most-common cancer in the world, but is the number-one non-skin cancer in United States men. Prostate cancer affected eighteen percent of American men and caused death in three percent in 2005.[71] In Japan, death from prostate cancer was one-fifth to one-half the rates in the United States and Europe in the 1990s.[72] In India in the 1990s, half of the people with prostate cancer confined to the prostate died within ten years.[73] African-American men have 50–60 times more prostate cancer and prostate cancer deaths than men in Shanghai, China.[74] In Nigeria, two percent of men develop prostate cancer and 64% of them are dead after two years.[75]

In patients that undergo treatment, the most important clinical prognostic indicators of disease outcome are stage, pre-therapy PSA level and Gleason score. In general, the higher the grade and the stage the poorer the prognosis. Nomograms can be used to calculate the estimated risk of the individual patient. The predictions are based on the experience of large groups of patients suffering from cancers at various stages.[76]

In 1941, Charles Huggins reported that androgen ablation therapy causes regression of primary and metastatic androgen-dependent prostate cancer.[77] Androgen ablation therapy causes remission in 80-90% of patients undergoing therapy, resulting in a median progression-free survival of 12 to 33 months. After remission, an androgen-independent phenotype typically emerges, wherein the median overall survival is 23–37 months from the time of initiation of androgen ablation therapy.[78] The actual mechanism contributes to the progression of prostate cancer is not clear and may vary between individual patient. A few possible mechanisms have been proposed.[79] Androgen at a concentration of 10-fold higher than the physiological concentration has also been shown to cause growth suppression and reversion of androgen-independent prostate cancer xenografts or androgen-independent prostate tumors derived in vivo model to an androgen-stimulated phenotype in athymic mice.[80][81] These observation suggest the possibility to use androgen to treat the development of relapsed androgen-independent prostate tumors in patients. Oral infusion of green tea polyphenols, a potential alternative therapy for prostate cancer by natural compounds, has been shown to inhibit the development, progression, and metastasis as well in autochthonous transgenic adenocarcinoma of the mouse prostate (TRAMP) model, which spontaneously develops prostate cancer.[82]

Many prostate cancers are not destined to be lethal, and most men will ultimately die from causes other than of the disease. Decisions about treatment type and timing may, therefore, be informed by an estimation of the risk that the tumor will ultimately recur after treatment and/or progress to metastases and mortality. Several tools are available to help predict outcomes such as pathologic stage and recurrence after surgery or radiation therapy. Most combine stage, grade, and PSA level, and some also add the number or percent of biopsy cores positive, age, and/or other information.

The D’Amico classification stratifies men to low, intermediate, or high risk based on stage, grade, and PSA. It is used widely in clinical practice and research settings. The major downside to the 3-level system is that it does not account for multiple adverse parameters (e.g., high Gleason score and high PSA) in stratifying patients.

The Partin tables predict pathologic outcomes (margin status, extraprostatic extension, and seminal vesicle invasion) based on the same 3 variables, and are published as lookup tables.

The Kattan nomograms predict recurrence after surgery and/or radiation therapy, based on data available either at time of diagnosis or after surgery. The nomograms can be calculated using paper graphs, or using software available on a website or for handheld computers. The Kattan score represents the likelihood of remaining free of disease at a given time interval following treatment.

The UCSF Cancer of the Prostate Risk Assessment (CAPRA) score predicts both pathologic status and recurrence after surgery. It offers comparable accuracy as the Kattan preoperative nomogram, and can be calculated without paper tables or a calculator. Points are assigned based on PSA, Grade, stage, age, and percent of cores positive; the sum yields a 0–10 score, with every 2 points representing roughly a doubling of risk of recurrence. The CAPRA score was derived from community-based data in the CaPSURE database. It has been validated among over 10,000 prostatectomy patients, including patients from CaPSURE[83]; the SEARCH registry, representing data from several Veterans Administration and active military medical centers[84]; a multi-institutional cohort in Germany[85]; and the prostatectomy cohort at Johns Hopkins University.[86]

[edit] Epidemiology

Age-standardized death from prostate cancer per 100,000 inhabitants in 2004.[87]
no data less than 4 4-8 8-12 12-16 16-20 20-24 24-28 28-32 32-36 36-40 40-44 more than 44

Rates of prostate cancer vary widely across the world. Although the rates vary widely between countries, it is least common in South and East Asia, more common in Europe, and most common in the United States.[1] According to the American Cancer Society, prostate cancer is least common among Asian men and most common among black men, with figures for white men inbetween.[88][89] However, these high rates may be affected by increasing rates of detection.[90]

Prostate cancer develops most frequently in men over fifty. This cancer can occur only in men, as the prostate is absent in the female reproductive tract. It is the most common type of cancer in men in the United States with 186,000 new cases in 2008 and 28,600 deaths.[91] It is the second leading cause of cancer death in men after lung cancer. In the United Kingdom it is also the second most common cause of cancer death after lung cancer, where around 35,000 cases are diagnosed every year and of which around 10,000 die of it. However, many men that develop prostate cancer never have symptoms, undergo no therapy, and eventually die of other causes. That is because malignant neoplasms of the prostate are, in most cases, slow-growing, and because most of those affected are over 60. Hence they often die of causes unrelated to the prostate cancer, such as heart/circulatory disease, pneumonia, other unconnected cancers, or old age. Many factors, including genetics and diet, have been implicated in the development of prostate cancer. The Prostate Cancer Prevention Trial found that finasteride reduces the incidence of prostate cancer rate by 30%. There had been a controversy about this also increasing the risk of more aggressive cancers, but more recent research showed this was not the case.[43][92]

[edit] History

Although the prostate was first described by Venetian anatomist Niccolò Massa in 1536, and illustrated by Flemish anatomist Andreas Vesalius in 1538, prostate cancer was not identified until 1853.[93] Prostate cancer was initially considered a rare disease, probably because of shorter life expectancies and poorer detection methods in the 19th century. The first treatments of prostate cancer were surgeries to relieve urinary obstruction.[94] Removal of the entire gland (radical perineal prostatectomy) was first performed in 1904 by Hugh H. Young at Johns Hopkins Hospital.[95] Surgical removal of the testes (orchiectomy) to treat prostate cancer was first performed in the 1890s, but with limited success. Transurethral resection of the prostate (TURP) replaced radical prostatectomy for symptomatic relief of obstruction in the middle of the 20th century because it could better preserve penile erectile function. Radical retropubic prostatectomy was developed in 1983 by Patrick Walsh.[96] This surgical approach allowed for removal of the prostate and lymph nodes with maintenance of penile function.

In 1941, Charles B. Huggins published studies in which he used estrogen to oppose testosterone production in men with metastatic prostate cancer. This discovery of "chemical castration" won Huggins the 1966 Nobel Prize in Physiology or Medicine.[97] The role of the hormone GnRH in reproduction was determined by Andrzej W. Schally and Roger Guillemin, who both won the 1977 Nobel Prize in Physiology or Medicine for this work.

Receptor agonists, such as leuprolide and goserelin, were subsequently developed and used to treat prostate cancer.[98][99]

Radiation therapy for prostate cancer was first developed in the early 20th century and initially consisted of intraprostatic radium implants. External beam radiation became more popular as stronger radiation sources became available in the middle of the 20th century. Brachytherapy with implanted seeds was first described in 1983.[100] Systemic chemotherapy for prostate cancer was first studied in the 1970s. The initial regimen of cyclophosphamide and 5-fluorouracil was quickly joined by multiple regimens using a host of other systemic chemotherapy drugs.[101]

Jonathan Simons and his laboratories at Johns Hopkins and Emory made original contributions in the molecular biology of cytokines in human prostate cancer metastasis, and in the molecular pharmacology and genetic therapy of metastatic prostate cancer.

[edit] Research

The insulin-like growth factor signaling axis is thought to play a key role in the progression of prostate carcinoma. It consists of two ligands (IGF-1 and IGF-2), two receptors (IGF-IR and IGF-IIR) and six related high-affinity IGF-binding proteins (IGFBP 1-6).[102] Altered expression of IGF axis members has been implicated in the development of many different types of cancers, including prostate.[103][104]

[edit] Prostate cancer models

Scientists have established a few prostate cancer cell lines to investigate the mechanism involved in the progression of prostate cancer. LNCaP, PC-3 (PC3), and DU-145 (DU145) are commonly used prostate cancer cell lines. The LNCaP cancer cell line was established from a human lymph node metastatic lesion of prostatic adenocarcinoma. PC-3 and DU-145 cells were established from human prostatic adenocarcinoma metastatic to bone and to brain, respectively. LNCaP cells express androgen receptor (AR); however, PC-3 and DU-145 cells express very little or no AR. AR, an androgen-activated transcription factor, belongs to the steroid nuclear receptor family. Development of the prostate is dependent on androgen signaling mediated through AR, and AR is also important during the development of prostate cancer. The proliferation of LNCaP cells is androgen-dependent but the proliferation of PC-3 and DU-145 cells is androgen-insensitive. Elevation of AR expression is often observed in advanced prostate tumors in patients.[105][106] Some androgen-independent LNCaP sublines have been developed from the ATCC androgen-dependent LNCaP cells after androgen deprivation for study of prostate cancer progression. These androgen-independent LNCaP cells have elevated AR expression and express prostate specific antigen upon androgen treatment. The paradox is that androgens inhibit the proliferation of these androgen-independent prostate cancer cells.[107][108][109]

[edit] References

  1. ^ a b "IARC Worldwide Cancer Incidence Statistics—Prostate". JNCI Cancer Spectrum. Oxford University Press. December 19, 2001. http://web.archive.org/web/20060205235509/http://www.jncicancerspectrum.oxfordjournals.org/cgi/statContent/cspectfstat;99. Retrieved on 5 April 2007 through the Internet Archive
  2. ^ Aumüller, G. (1979). Prostate Gland and Seminal Vesicles. Berlin-Heidecool.lberg: Springer-Verlag.
  3. ^ Moore, K.; Dalley, A. (1999). Clinically Oriented Anatomy. Baltimore, Maryland: Lippincott Williams & Wilkins.
  4. ^ Steive, H. (1930). "Männliche Genitalorgane". Handbuch der mikroskopischen Anatomie des Menschen. Vol. VII Part 2. Berlin: Springer. pp. 1–399.
  5. ^ Smith JA, Chan RC, Chang SS, et al. (2007). "A comparison of the incidence and location of positive surgical margins in robotic assisted laparoscopic radical prostatectomy and open retropubic radical prostatectomy". J. Urol. 178 (6): 2385–9; discussion 2389–90. doi:10.1016/j.juro.2007.08.008. PMID 17936849.
  6. ^ Miller, DC; Hafez, KS, Stewart, A, et al. (2003). "Prostate carcinoma presentation, diagnosis, and staging: an update from the National Cancer Data Base". Cancer 98: 1169. doi:10.1002/cncr.11635. PMID 12973840.
  7. ^ van der Cruijsen-Koeter, IW; Vis AN, Roobol MJ, Wildhagen MF, de Koning HJ, van der Kwast TH, Schroder FH (July 2005). "Comparison of screen detected and clinically diagnosed prostate cancer in the European randomized study of screening for prostate cancer, section rotterdam". Urol 174 (1): 121–5. doi:10.1097/01.ju.0000162061.40533.0f. PMID 15947595.
  8. ^ Hsing, Ann W.; Anand P. Chokkalingam (May 1 2006). "Prostate cancer epidemiology". Frontiers in Bioscience 11: 1388–1413. doi:10.2741/1891. http://www.bioscience.org/2006/v11/af/1891/fulltext.htm.
  9. ^ Hankey, BF; Feuer EJ, Clegg LX, Hayes RB, Legler JM, Prorok PC, Ries LA, Merrill RM, Kaplan RS (June 16 1999). "Cancer surveillance series: interpreting trends in prostate cancer—part I: Evidence of the effects of screening in recent prostate cancer incidence, mortality, and survival rates". J Natl Cancer Inst 91 (12): 1017–24. doi:10.1093/jnci/91.12.1017. PMID 10379964.
  10. ^ Breslow, N; Chan CW, Dhom G, Drury RA, Franks LM, Gellei B, Lee YS, Lundberg S, Sparke B, Sternby NH, Tulinius H. (November 15 1977). "Latent carcinoma of prostate at autopsy in seven areas. The International Agency for Research on Cancer, Lyons, France". Int J Cancer 20 (5): 680–8. doi:10.1002/ijc.2910200506. PMID 924691.
  11. ^ Jemal A; Murray T, Ward E, Samuels A, Tiwari RC, Ghafoor A, Feuer EJ, Thun MJ (Jan-February 2005). "Cancer statistics, 2005". CA Cancer J Clin 55 (1): 10–30. doi:10.3322/canjclin.55.1.10. PMID 15661684. Erratum in: CA Cancer J Clin. 2005 Jul-Aug;55(4):259
  12. ^ Hoffman, RM; Gilliland FD; Eley JW; Harlan LC; Stephenson RA; Stanford JL; Albertson PC; Hamilton AS; Hunt WC; Potosky AL (March 7 2001). "Racial and ethnic differences in advanced-stage prostate cancer: the Prostate Cancer Outcomes Study". J Natl Cancer Inst 93 (5): 388–95. doi:10.1093/jnci/93.5.388. PMID 11238701.
  13. ^ Steinberg, GD; Carter BS; Beaty TH; Childs B; Walsh PC (1990). "Family history and the risk of prostate cancer". Prostate 17 (4): 337–47. doi:10.1002/pros.2990170409. PMID 2251225.
  14. ^ Lichtenstein, P; Holm NV; Verkasalo PK; Iliadou A; Kaprio J; Koskenvuo M; Pukkala E; Skytthe A; Hemminki K (July 13 2000). "Environmental and heritable factors in the causation of cancer—analyses of cohorts of twins from Sweden, Denmark, and Finland". N Engl J Med 343 (2): 78–85. doi:10.1056/NEJM200007133430201. PMID 10891514.
  15. ^ Struewing, JP; Hartge P; Wacholder S; Baker SM; Berlin M; McAdams M; Timmerman MM; Brody LC; Tucker MA (May 15 1997). "The risk of cancer associated with specific mutations of BRCA1 and BRCA2 among Ashkenazi Jews". N Engl J Med 336 (20): 1401–8. doi:10.1056/NEJM199705153362001. PMID 9145676.
  16. ^ http://www.cypsystems.com/research/Studies_britishJUrology_selenoexcell.pdf
  17. ^ http://jnci.oxfordjournals.org/cgi/content/full/92/24/2018?ijkey=539435fb412430958437c74efd2875be7c94042a
  18. ^ Peters U, Leitzmann MF, Chatterjee N, Wang Y, Albanes D, Gelmann EP, Friesen MD, Riboli E, Hayes RB (2007). "Serum lycopene, other carotenoids, and prostate cancer risk: a nested case-control study in the prostate, lung, colorectal, and ovarian cancer screening trial". Cancer Epidemiol. Biomarkers Prev. 16 (5): 962–8. doi:10.1158/1055-9965.EPI-06-0861. PMID 17507623. http://cebp.aacrjournals.org/cgi/pmidlookup?view=long&pmid=17507623. Retrieved 17 December 2007.
  19. ^ Schulman, CC; Ekane S; Zlotta AR (September 2001). "Nutrition and prostate cancer: evidence or suspicion?". Urology 58 (3): 318–34. doi:10.1016/S0090-4295(01)01262-6. PMID 11549473.
  20. ^ a b c d Figueiredo JC, Grau MV, Haile RW, Sandler RS, Summers RW, Bresalier RS, Burke CA, McKeown-Eyssen GE, Baron JA (March 2009). "Folic acid and risk of prostate cancer: results from a randomized clinical trial". J. Natl. Cancer Inst. 101 (6): 432–5. doi:10.1093/jnci/djp019. PMID 19276452.
  21. ^ Jacobs, EJ; Rodriguez C, Mondul AM, Connell CJ, Henley SJ, Calle EE, Thun MJ (July 6 2005). "A large cohort study of aspirin and other nonsteroidal anti-inflammatory drugs and prostate cancer incidence". J Natl Cancer Inst 97 (13): 975–80. PMID 15998950.
  22. ^ Shannon, J; Tewoderos S, Garzotto M, Beer TM, Derenick R, Palma A, Farris PE (August 15 2005). "Statins and prostate cancer risk: a case-control study". Am J Epidemiol 162 (4): 318–25. doi:10.1093/aje/kwi203. PMID 16014776. Epub 2005 July 13
  23. ^ Dennis, LK; Lynch CF; Torner JC (July 2002). "Epidemiologic association between prostatitis and prostate cancer". Urology 60 (1): 78–83. doi:10.1016/S0090-4295(02)01637-0. PMID 12100928.
  24. ^ Calle, EE; Rodriguez C, Walker-Thurmond K, Thun MJ (April 24 2003). "Overweight, obesity, and mortality from cancer in a prospectively studied cohort of U.S. adults". N Engl J Med 348 (17): 1625–38. doi:10.1056/NEJMoa021423. PMID 12711737.
  25. ^ Gann, PH; Hennekens CH, Ma J, Longcope C, Stampfer MJ (August 21 1996). "Prospective study of sex hormone levels and risk of prostate cancer". J Natl Cancer Inst 88 (16): 1118–26. doi:10.1093/jnci/88.16.1118. PMID 8757191.
  26. ^ "Veterans exposed to Agent Orange have higher rates of prostate cancer recurrence". Medical College of Georgia News. May 20, 2007. https://my.mcg.edu/portal/page/portal/News/archive/2007/Veterans%20exposed%20to%20Agent%20%20Orange%20have%20higher%20rates%20of%20prost.
  27. ^ Urisman, Anatoly; Ross J Molinaro, Nicole Fischer, Sarah J Plummer, Graham Casey, Eric A Klein, Krishnamurthy Malathi, Cristina Magi-Galluzzi, Raymond R Tubbs, Don Ganem, Robert H Silverman, Joseph L DeRisi (2006-03). "Identification of a novel Gammaretrovirus in prostate tumors of patients homozygous for R462Q RNASEL variant". PLoS Pathogens 2 (3): e25. doi:10.1371/journal.ppat.0020025. ISSN 1553-7374. http://www.ncbi.nlm.nih.gov/pubmed/16609730. Retrieved 15 November 2009.
  28. ^ Schlaberg, Robert; Daniel J Choe, Kristy R Brown, Harshwardhan M Thaker, Ila R Singh (22 September 2009). "XMRV is present in malignant prostatic epithelium and is associated with prostate cancer, especially high-grade tumors". Proceedings of the National Academy of Sciences of the United States of America 106 (38): 16351-16356. doi:10.1073/pnas.0906922106. ISSN 1091-6490. http://www.ncbi.nlm.nih.gov/pubmed/19805305. Retrieved 15 November 2009.
  29. ^ Hohn, Oliver; Hans Krause, Pia Barbarotto, Lars Niederstadt, Nadine Beimforde, Joachim Denner, Kurt Miller, Reinhard Kurth, Norbert Bannert (2009). "Lack of evidence for xenotropic murine leukemia virus-related virus(XMRV) in German prostate cancer patients". Retrovirology 6: 92. doi:10.1186/1742-4690-6-92. ISSN 1742-4690. http://www.ncbi.nlm.nih.gov/pubmed/19835577. Retrieved 15 November 2009.
  30. ^ Essink-Bot, ML; de Koning HJ, Nijs HG, Kirkels WJ, van der Maas PJ, Schroder FH (June 17 1998). "Short-term effects of population-based screening for prostate cancer on health-related quality of life". J Natl Cancer Inst 90 (12): 925–31. doi:10.1093/jnci/90.12.925. PMID 9637143.
  31. ^ Chuang AY, Demarzo AM, Veltri RW, Sharma RB, Bieberich CJ, Epstein JI (2007). "Immunohistochemical Differentiation of High-grade Prostate Carcinoma From Urothelial Carcinoma". The American Journal of Surgical Pathology 31 (8): 1246–1255. doi:10.1097/PAS.0b013e31802f5d33. PMID 17667550.
  32. ^ Iyer M, Salazar FB, Lewis X, Zhang L, Wu L, Carey M and Gambhir SS. Non-invasive imaging of a transgenic mouse model using a prostate-specific two-step transcriptional amplification strategy. Transg Res.2005; 14(1): 47–55
  33. ^ A Prostate Cancer Revolution. Newsweek, April 26, 2007.
  34. ^ Hansel DE, DeMarzo AM, Platz EA, et al. (2007). "Early prostate cancer antigen expression in predicting presence of prostate cancer in men with histologically negative biopsies". J. Urol. 177 (5): 1736–40. doi:10.1016/j.juro.2007.01.013. PMID 17437801.
  35. ^ Sartor AO, Hricak H, Wheeler TM, et al. (December 2008). "Evaluating localized prostate cancer and identifying candidates for focal therapy". Urology 72 (6 Suppl): S12–24. doi:10.1016/j.urology.2008.10.004. PMID 19095124.
  36. ^ Ronquist G, Carlsson L, Larsson A, Nilsson BO: "Prostasomes: Proceedings from a symposium held at the Wenner-Gren Centre, Stockholm, June 2001" pp. 1-9. Portland Press , London
  37. ^ Wigle DT, Turner MC, Gomes J, Parent ME (March 2008). "Role of hormonal and other factors in human prostate cancer". J Toxicol Environ Health B Crit Rev 11 (3-4): 242–59. doi:10.1080/10937400701873548. PMID 18368555.
  38. ^ Strom, SS; Yamamura Y, Duphorne CM, Spitz MR, Babaian RJ, Pillow PC, Hursting SD (1999). "Phytoestrogen intake and prostate cancer: a case-control study using a new database". Nutr Cancer 33 (1): 20–5. PMID 10227039. Erratum in: Nutr Cancer 2000;36(2):243.
  39. ^ Steiner, MS; Pound, CR, Gingrich, JR, et al. (2002). "Acapodene (GTx-006) reduces high-grade prostatic intraepithelial neoplasia in phase II clinical trial (abstract)". Proc Am Soc Clin Oncol 21: 180a.
  40. ^ Price, D; Stein, B, Goluboff, E, et al. (2005). "Double-blind, placebo-controlled trial of toremifene for the prevention of prostate cancer in men with high-grade prostatic intrapeithelial neoplasia (abstract)". J Clin Oncol 23: 106s.
  41. ^ Thompson, IM; Goodman PJ, Tangen CM, Lucia MS, Miller GJ, Ford LG, Lieber MM, Cespedes RD, Atkins JN, Lippman SM, Carlin SM, Ryan A, Szczepanek CM, Crowley JJ, Coltman CA Jr. (July 17 2003). "The influence of finasteride on the development of prostate cancer". N Engl J Med 349 (3): 215–24. doi:10.1056/NEJMoa030660. PMID 12824459.
  42. ^ Andriole, GL; Roehrborn C, Schulman C, Slawin KM, Somerville M, Rittmaster RS (September 2004). "Effect of dutasteride on the detection of prostate cancer in men with benign prostatic hyperplasia". Urology 64 (3): 537–41; discussion 542–3. doi:10.1016/j.urology.2004.04.084. PMID 15351586.
  43. ^ a b c Redman, M.W.; Tangen, C.M.; Goodman, P.J.; Lucia, M.S.; Coltman Jr, C.A.; Thompson, I.M. (2008). "Finasteride does not increase the risk of high-grade prostate cancer: a bias-adjusted modeling approach". Cancer prevention research (Philadelphia, Pa.) 1 (3): 174–181. doi:10.1158/1940-6207.CAPR-08-0092. PMID 19138953. edit
  44. ^ Lee AH, Fraser ML, Meng X, Binns CW (April 2006). "Protective effects of green tea against prostate cancer". Expert Rev Anticancer Ther 6 (4): 507–13. doi:10.1586/14737140.6.4.507. PMID 16613539.
  45. ^ Kikuchi N, Ohmori K, Shimazu T, et al. (August 2006). "No association between green tea and prostate cancer risk in Japanese men: the Ohsaki Cohort Study". Br. J. Cancer 95 (3): 371–3. doi:10.1038/sj.bjc.6603230. PMID 16804523.
  46. ^ Bettuzzi S, Brausi M, Rizzi F, Castagnetti G, Peracchia G, Corti A (2006). "Chemoprevention of human prostate cancer by oral administration of green tea catechins in volunteers with high-grade prostate intraepithelial neoplasia: a preliminary report from a one-year proof-of-principle study". Cancer Res 66 (2): 1234–40. doi:10.1158/0008-5472.CAN-05-1145. PMID 16424063.
  47. ^ "Multivitamin prostate warning". Health. BBC NEWS. 16 May 2007. http://news.bbc.co.uk/1/hi/health/6657795.stm. Retrieved 23 April 2008.
  48. ^ Lawson KA, Wright ME, Subar A, Mouw T, Hollenbeck A, Schatzkin A, Leitzmann MF (May 2007). "Multivitamin use and risk of prostate cancer in the National Institutes of Health-AARP Diet and Health Study". J. Natl. Cancer Inst. 99 (10): 754–64. doi:10.1093/jnci/djk177. PMID 17505071.
  49. ^ "Broccoli May Help Cut Prostate Cancer, Broccoli, Cauliflower May Make Aggressive Prostate Cancer Less Likely". CBS News. 24 July 2007. http://www.cbsnews.com/stories/2007/07/24/health/webmd/main3094509.shtml. Retrieved 23 April 2008.
  50. ^ Kirsh VA, Peters U, Mayne ST, Subar AF, Chatterjee N, Johnson CC, Hayes RB (August 2007). "Prospective study of fruit and vegetable intake and risk of prostate cancer". J. Natl. Cancer Inst. 99 (15): 1200–9. doi:10.1093/jnci/djm065. PMID 17652276.
  51. ^ Sarkar FH, Li Y (December 2004). "Indole-3-carbinol and prostate cancer". J. Nutr. 134 (12 Suppl): 3493S–3498S. PMID 15570059.
  52. ^ Hsu JC, Zhang J, Dev A, Wing A, Bjeldanes LF, Firestone GL (November 2005). "Indole-3-carbinol inhibition of androgen receptor expression and downregulation of androgen responsiveness in human prostate cancer cells". Carcinogenesis 26 (11): 1896–904. doi:10.1093/carcin/bgi155. PMID 15958518. http://carcin.oxfordjournals.org/cgi/content/full/26/11/1896. Retrieved 12 September 2008.
  53. ^ Giles GG, Severi G, English DR, McCredie MR, Borland R, Boyle P, Hopper JL (August 2003). "Sexual factors and prostate cancer". BJU Int. 92 (3): 211–6. doi:10.1046/j.1464-410X.2003.04319.x. PMID 12887469.
  54. ^ Leitzmann, Michael F. (April 7 2004). "Ejaculation Frequency and Subsequent Risk of Prostate Cancer". JAMA 291 (13): 1578–86. doi:10.1001/jama.291.13.1578. 2004;291:1578-1586. PMID 15069045. PMID: 15069045
  55. ^ Douglas Fox (16 July 2003). "Masturbating may protect against prostate cancer". New Scientist. http://www.newscientist.com/article/dn3942-masturbating-may-protect-against-prostate-cancer.html. Retrieved 23 April 2008.
  56. ^ Leitzmann MF, Platz EA, Stampfer MJ, Willett WC, Giovannucci E (April 2004). "Ejaculation frequency and subsequent risk of prostate cancer". JAMA 291 (13): 1578–86. doi:10.1001/jama.291.13.1578. PMID 15069045.
  57. ^ Dimitropoulou, Polyxeni; Artitaya Lophatananon, Douglas Easton, Richard Pocock, David P. Dearnaley, Michelle Guy, Steven Edwards, Lynne O'Brien, Amanda Hall, Rosemary Wilkinson, Rosalind Eeles, Kenneth R. Muir (November 11, 2008). "Sexual activity and prostate cancer risk in men diagnosed at a younger age". BJU International 103 (2): 178–185. doi:10.1111/j.1464-410X.2008.08030.x. OCLC 10.1111/j.1464-410X.2008.08030.x.
  58. ^ Berquin IM, Min Y, Wu R, et al. (July 2007). "Modulation of prostate cancer genetic risk by omega-3 and omega-6 fatty acids". J. Clin. Invest. 117 (7): 1866–75. doi:10.1172/JCI31494. PMID 17607361.
  59. ^ a b Gann, PH and Giovannucci (2005). "Prostate Cancer and Nutrition" (PDF). http://www.prostatecancerfoundation.org/atf/cf/%7B705B3273-F2EF-4EF6-A653-E15C5D8BB6B1%7D/Nutrition_Guide.pdf. Retrieved February 20, 2006. in .pdf format.
  60. ^ a b c Männistö S, Pietinen P, Virtanen MJ, Salminen I, Albanes D, Giovannucci E, Virtamo J (December 2003). "Fatty acids and risk of prostate cancer in a nested case-control study in male smokers" (PDF). Cancer Epidemiol. Biomarkers Prev. 12 (12): 1422–8. PMID 14693732. http://cebp.aacrjournals.org/cgi/reprint/12/12/1422.pdf.
  61. ^ Chavarro et al., "A prospective study of blood trans fatty acid levels and risk of prostate cancer," Proc. Amer. Assoc. Cancer Res., Volume 47, 2006 [1].
  62. ^ a b c Crowe FL, Allen NE, Appleby PN, Overvad K, Aardestrup IV, Johnsen NF, Tjønneland A, Linseisen J, Kaaks R, Boeing H, Kröger J, Trichopoulou A, Zavitsanou A, Trichopoulos D, Sacerdote C, Palli D, Tumino R, Agnoli C, Kiemeney LA, Bueno-de-Mesquita HB, Chirlaque MD, Ardanaz E, Larrañaga N, Quirós JR, Sánchez MJ, González CA, Stattin P, Hallmans G, Bingham S, Khaw KT, Rinaldi S, Slimani N, Jenab M, Riboli E, Key TJ (November 2008). "Fatty acid composition of plasma phospholipids and risk of prostate cancer in a case-control analysis nested within the European Prospective Investigation into Cancer and Nutrition". Am. J. Clin. Nutr. 88 (5): 1353–63. PMID 18996872. http://www.ajcn.org/cgi/content/abstract/88/5/1353.
  63. ^ a b Kurahashi N, Inoue M, Iwasaki M, Sasazuki S, Tsugane AS (April 2008). "Dairy product, saturated fatty acid, and calcium intake and prostate cancer in a prospective cohort of Japanese men". Cancer Epidemiol. Biomarkers Prev. 17 (4): 930–7. doi:10.1158/1055-9965.EPI-07-2681. PMID 18398033.
  64. ^ "Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets". J Am Diet Assoc 103 (6): 748–65. 2003. doi:10.1053/jada.2003.50142. PMID 12778049.
  65. ^ Gerald L. Andriole, M.D., Robert L. Grubb, III, M.D., Saundra S. Buys, M.D., David Chia, Ph.D., Timothy R. Church, Ph.D., Mona N. Fouad, M.D., Edward P. Gelmann, M.D., et al. (18 March 2009). "Mortality Results from a Randomized Prostate-Cancer Screening Trial". The New England Journal of Medicine 360: 1310. doi:10.1056/NEJMoa0810696. PMID 19297565. http://content.nejm.org/cgi/content/full/NEJMoa0810696. Retrieved 19 March 2009.
  66. ^ http://www.nytimes.com/2009/03/19/health/19cancer.html?em
  67. ^ Mouraviev V, Evans B, Polascik TJ (2006). "Salvage prostate cryoablation after primary interstitial brachytherapy failure: a feasible approach". Prostate Cancer Prostatic Dis. 9 (1): 99–101. doi:10.1038/sj.pcan.4500853. PMID 16314889.
  68. ^ "Prostate Cancer At A Glance". ShaveMagazine.com. http://www.shavemagazine.com/body/health/090401/2.
  69. ^ http://yedda.com/questions/Low_fat_milk_causes_prostate_cancer_7351021963170/
  70. ^ ACS :: What Are The Risk Factors for Prostate Cancer?
  71. ^ Jemal, A; Murray T; Ward E; Samuels A; Tiwari RC; Ghafoor A; Feuer EJ; Thun MJ (Jan-February 2005). "Cancer statistics, 2005". CA Cancer J Clin 55 (1): 10–30. doi:10.3322/canjclin.55.1.10. PMID 15661684. Erratum in: CA Cancer J Clin. 2005 Jul-Aug;55(4):259.
  72. ^ Wakai, K (February 2005). "Descriptive epidemiology of prostate cancer in Japan and Western countries". Nippon Rinsho 63 (2): 207–12. PMID 15714967. Review. (Japanese)
  73. ^ Yeole, BB; Sunny L (Jun-December 2001). "Population based survival from prostate cancer in Mumbai (Bombay), India". Indian J Cancer 38 (2–4): 126–32. PMID 1259345.
  74. ^ Hsing, AW; Tsao L, Devesa SS (January 1 2000). "International trends and patterns of prostate cancer incidence and mortality". Int J Cancer 85 (1): 60–7. doi:10.1002/(SICI)1097-0215(20000101)85:1<60::AID-IJC11>3.0.CO;2-B. PMID 10585584.
  75. ^ Osegbe, DN (April 1997). "Prostate cancer in Nigerians: facts and nonfacts". J Urol 157 (4): 1340–3. doi:10.1016/S0022-5347(01)64966-8. PMID 9120935.
  76. ^ Di Blasio CJ, Rhee AC, Cho D, Scardino PT, Kattan MW (2003). "Predicting clinical end points: treatment nomograms in prostate cancer". Semin Oncol 30 (5): 567–86. doi:10.1016/S0093-7754(03)00351-8. PMID 14571407.
  77. ^ Huggins C, Steven RE and Hodges CV, Studies on prostatic cancer. Arch. Sug. 43:209–223, 1941.
  78. ^ Hellerstedt BA, Pienta KJ (2002). "The current state of hormonal therapy for prostate cancer". CA Cancer J Clin 52 (3): 154–79. doi:10.3322/canjclin.52.3.154. PMID 12018929.
  79. ^ Feldman BJ, Feldman D (October 2001). "The development of androgen-independent prostate cancer". Nat. Rev. Cancer 1 (1): 34–45. doi:10.1038/35094009. PMID 11900250.
  80. ^ Chuu CP, Hiipakka RA, Fukuchi J, Kokontis JM, Liao S (March 2005). "Androgen causes growth suppression and reversion of androgen-independent prostate cancer xenografts to an androgen-stimulated phenotype in athymic mice". Cancer Res. 65 (6): 2082–4. doi:10.1158/0008-5472.CAN-04-3992. PMID 15781616.
  81. ^ Chuu CP, Hiipakka RA, Kokontis JM, Fukuchi J, Chen RY, Liao S (July 2006). "Inhibition of tumor growth and progression of LNCaP prostate cancer cells in athymic mice by androgen and liver X receptor agonist". Cancer Res. 66 (13): 6482–6. doi:10.1158/0008-5472.CAN-06-0632. PMID 16818617.
  82. ^ Gupta S, Hastak K, Ahmad N, Lewin JS, Mukhtar H (August 2001). "Inhibition of prostate carcinogenesis in TRAMP mice by oral infusion of green tea polyphenols". Proc. Natl. Acad. Sci. U.S.A. 98 (18): 10350–5. doi:10.1073/pnas.171326098. PMID 11504910.
  83. ^ Cooperberg MR, Pasta DJ, Elkin EP, et al. (June 2005). "The University of California, San Francisco Cancer of the Prostate Risk Assessment score: a straightforward and reliable preoperative predictor of disease recurrence after radical prostatectomy". J. Urol. 173 (6): 1938–42. doi:10.1097/01.ju.0000158155.33890.e7. PMID 15879786.
  84. ^ Cooperberg MR, Freedland SJ, Pasta DJ, et al. (November 2006). "Multiinstitutional validation of the UCSF cancer of the prostate risk assessment for prediction of recurrence after radical prostatectomy". Cancer 107 (10): 2384–91. doi:10.1002/cncr.22262. PMID 17039503.
  85. ^ May M, Knoll N, Siegsmund M, et al. (November 2007). "Validity of the CAPRA score to predict biochemical recurrence-free survival after radical prostatectomy. Results from a european multicenter survey of 1,296 patients". J. Urol. 178 (5): 1957–62; discussion 1962. doi:10.1016/j.juro.2007.07.043. PMID 17868719.
  86. ^ Zhao KH, Hernandez DJ, Han M, Humphreys EB, Mangold LA, Partin AW (August 2008). "External validation of University of California, San Francisco, Cancer of the Prostate Risk Assessment score". Urology 72 (2): 396–400. doi:10.1016/j.urology.2007.11.165. PMID 18372031.
  87. ^ "WHO Disease and injury country estimates". World Health Organization. 2009. http://www.who.int/healthinfo/global_burden_disease/estimates_country/en/index.html. Retrieved Nov. 11, 2009.
  88. ^ Overview: Prostate Cancer—What Causes Prostate Cancer? American Cancer Society (2 May 2006). Retrieved on 5 April 2007
  89. ^ Prostate Cancer FAQs. State University of New York School of Medicine Department of Urology (31 August 2006). Retrieved on 5 April 2007
  90. ^ Potosky A, Miller B, Albertsen P, Kramer B (1995). "The role of increasing detection in the rising incidence of prostate cancer". JAMA 273 (7): 548–52. doi:10.1001/jama.273.7.548. PMID 7530782.
  91. ^ Lippman SM, Klein EA, Goodman PJ, et al. (January 2009). "Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT)". JAMA 301 (1): 39–51. doi:10.1001/jama.2008.864. PMID 19066370.
  92. ^ Gine Kolata (June 15, 2008). "New Take on a Prostate Drug, and a New Debate". NY Times. http://www.nytimes.com/2008/06/15/health/15prostate.html?ei=5087&em=&en=813eaa4e10f57756&ex=1213675200&adxnnl=1&adxnnlx=1213503418-GD4DbGjYsDxqV/xuGWnE1A. Retrieved 15 June 2008.
  93. ^ Adams, J. (1853) "The case of scirrhous of the prostate gland with corresponding affliction of the lymphatic glands in the lumbar region and in the pelvis" in: Lancet 1, 393 (1853).
  94. ^ Lytton B (June 2001). "Prostate cancer: a brief history and the discovery of hormonal ablation treatment". J. Urol. 165 (6 Pt 1): 1859–62. doi:10.1016/S0022-5347(05)66228-3. PMID 11371867.
  95. ^ Young, H. H. Four cases of radical prostatectomy. Johns Hopkins Bull. 16, 315 (1905).
  96. ^ Walsh PC, Lepor H, Eggleston JC (1983). "Radical prostatectomy with preservation of sexual function: anatomical and pathological considerations". Prostate 4 (5): 473–85. doi:10.1002/pros.2990040506. PMID 6889192.
  97. ^ Huggins, C. B. & Hodges, C. V. (1941) "Studies on prostate cancer: 1. The effects of castration, of estrogen and androgen injection on serum phosphatases in metastatic carcinoma of the prostate" in: 'Cancer Res. 1, 203 (1941).
  98. ^ Schally AV, Kastin AJ, Arimura A (November 1971). "Hypothalamic follicle-stimulating hormone (FSH) and luteinizing hormone (LH)-regulating hormone: structure, physiology, and clinical studies". Fertil. Steril. 22 (11): 703–21. PMID 4941683.
  99. ^ Tolis G, Ackman D, Stellos A, et al. (March 1982). "Tumor growth inhibition in patients with prostatic carcinoma treated with luteinizing hormone-releasing hormone agonists". Proc. Natl. Acad. Sci. U.S.A. 79 (5): 1658–62. doi:10.1073/pnas.79.5.1658. PMID 6461861.
  100. ^ Denmeade SR, Isaacs JT (May 2002). "A history of prostate cancer treatment". Nat. Rev. Cancer 2 (5): 389–96. doi:10.1038/nrc801. PMID 12044015.
  101. ^ Scott WW, Johnson DE, Schmidt JE, et al. (December 1975). "Chemotherapy of advanced prostatic carcinoma with cyclophosphamide or 5-fluorouracil: results of first national randomized study". J. Urol. 114 (6): 909–11. PMID 1104900.
  102. ^ Grotendorst GR, et al. (2000). "CCN proteins are distinct and should not be considered members of the insulin-like growth factor-binding protein superfamily.". Endocrinology 141: 2254–2256. doi:10.1210/en.141.6.2254. PMID 10830315.
  103. ^ Samani AA, et al. (2007). "The role of the IGF system in cancer growth and metastasis:overview and recent insights.". Endocrinology Reviews 28: 20–47. doi:10.1210/er.2006-0001. PMID 16931767.
  104. ^ Jenkins PJ, et al. (2004). "Evidence for a link between IGF-I and cancer.". European Journal of Endocrinology 151: S17–22. doi:10.1530/eje.0.151S017. PMID 15339239.
  105. ^ Linja MJ, Savinainen KJ, Saramäki OR, Tammela TL, Vessella RL, Visakorpi T (May 2001). "Amplification and overexpression of androgen receptor gene in hormone-refractory prostate cancer". Cancer Res. 61 (9): 3550–5. PMID 11325816.
  106. ^ Ford OH, Gregory CW, Kim D, Smitherman AB, Mohler JL (November 2003). "Androgen receptor gene amplification and protein expression in recurrent prostate cancer". J. Urol. 170 (5): 1817–21. doi:10.1097/01.ju.0000091873.09677.f4. PMID 14532783.
  107. ^ Kokontis J, Takakura K, Hay N, Liao S (March 1994). "Increased androgen receptor activity and altered c-myc expression in prostate cancer cells after long-term androgen deprivation". Cancer Res. 54 (6): 1566–73. PMID 7511045.
  108. ^ Umekita Y, Hiipakka RA, Kokontis JM, Liao S (October 1996). "Human prostate tumor growth in athymic mice: inhibition by androgens and stimulation by finasteride". Proc. Natl. Acad. Sci. U.S.A. 93 (21): 11802–7. doi:10.1073/pnas.93.21.11802. PMID 8876218.
  109. ^ Kokontis JM, Hsu S, Chuu CP, et al. (December 2005). "Role of androgen receptor in the progression of human prostate tumor cells to androgen independence and insensitivity". Prostate 65 (4): 287–98. doi:10.1002/pros.20285. PMID 16015608.

[edit] External links