Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. 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. 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 since men with the condition are older they often die of causes unrelated to the prostate cancer, such as heart/circulatory disease, pneumonia, other unconnected cancers, or old age. About 2/3 of cases are slow growing “pussycats”, the other third more aggressive, fast developing being known informally as “tigers”.
Prostate cancer is the most common malignancy in American men and the second leading cause of deaths from cancer, after lung cancer. According to the American Cancer Society’s most recent estimates, 192,280 new cases of prostate cancer would be diagnosed in 2009 and 27,360 would die from the disease.
The estimated lifetime risk of being diagnosed with the disease is 17.6% for Caucasians and 20.6% for African Americans. The lifetime risk of death from prostate cancer similarly is 2.8% and 4.7% respectively. As reflected in these numbers, prostate cancer is likely to impact the lives of a significant proportion of men that are alive today.
Over the years, however, the death rate from this disease has shown a steady decline, and currently, more than 2 million men in the U.S. are still alive after being diagnosed with prostate cancer at some point in their lives.
Although it is subject to some controversy, many experts in this field, therefore, recommend that beginning at age 40, all men should undergo screening for prostate cancer.
What causes Prostate Cancer?
The cause of prostate cancer is unknown, but the cancer is not thought to be related to benign prostatic hyperplasia (BPH). The risk (predisposing) factors for prostate cancer include advancing age, genetics (heredity), hormonal influences, and such environmental factors as toxins, chemicals, and industrial products. The chances of developing prostate cancer increase with age. Thus, prostate cancer under age 40 is extremely rare, while it is common in men older than 80 years of age. As a matter of fact, some studies have suggested that among men over 80 years of age, 50%-80% of them may have prostate cancer! More than 80% of prostate cancers are diagnosed in men older than 65 years of age.
As mentioned previously, African-American men are 1.6 times more likely than white men to develop prostate cancer. They are also 2.4 times more likely to die from their disease as compared to white men of a similar age. These differences in diagnosis and death rates are, however, more likely to reflect a difference in factors such as environmental exposure, diet, lifestyle, and health-seeking behavior rather than any racial susceptibility to prostate cancer. Recent studies indicate that this disparity is progressively decreasing with chances of complete cure in men undergoing treatment for organ-confined prostate cancer (cancer that is limited to within the prostate without spread outside the confines of the prostate gland), irrespective of race.
Genetics (heredity), as just mentioned, plays a role in the risk of developing a prostate cancer. Prostate cancer is more common among family members of individuals with prostate cancer. This risk may be two to three times greater than the risk for men without a family history of the disease. Earlier age at diagnosis (<60 years) in a first-degree relative (father or brother) and disease affecting more than one relative also increases the risk for developing prostate cancer.
Testosterone, the male hormone produced by the testicles, directly stimulates the growth of both normal prostate tissue and prostate cancer cells. Not surprisingly, therefore, this hormone is thought to be involved in the development and growth of prostate cancer. The important implication of the role of this hormone is that decreasing the level of testosterone should be (and usually is) effective in inhibiting the growth of prostate cancer.
Recent evidence has suggested that sexually transmitted infections are risk factors for developing prostate cancer. Men with a history of sexually transmitted infections have a 1.4 times greater chance of developing prostate cancer as compared men without this history.
Although still unproven, environmental factors, such as cigarette smoking and diets that are high in saturated fat, seem to increase the risk of prostate cancer. There is also a suggestion that obesity leads to an increased risk of having more aggressive, larger prostate cancer, which results in a poorer outcome after treatment. Additional substances or toxins in the environment or from industrial sources might also promote the development of prostate cancer, but these have not yet been clearly identified. Geographical influences also seem to play a role in the development of prostate cancer with men living in the Scandinavian and North American countries being at a higher risk for the disease as compared to those residing in Asian countries.
Of note, there is no proven relationship between the frequency of sexual activity and the chances of developing prostate cancer.
What are the Symptoms of Prostate Cancer?
In the early stages, prostate cancer often causes no symptoms for many years. As a matter of fact, these cancers frequently are first detected by an abnormality on a blood test (the PSA, discussed below) or as a hard nodule (lump) in the prostate gland. Occasionally, the doctor may first feel a hard nodule during a routine digital (done with the finger) rectal examination. The prostate gland is located immediately in front of the rectum.
Rarely, in more advanced cases, the cancer may enlarge and press on the urethra. As a result, the flow of urine diminishes and urination becomes more difficult. Patients may also experience burning with urination or blood in the urine. As the tumor continues to grow, it can completely block the flow of urine, resulting in a painfully obstructed and enlarged urinary bladder. These symptoms by themselves, however, do not confirm the presence of prostate cancer. Most of these symptoms can occur in men with non-cancerous (benign) enlargement of the prostate (the most common form of prostate enlargement). However, the occurrence of these symptoms should prompt an evaluation by the doctor to rule out cancer and provide appropriate treatment.
Furthermore, in the later stages, prostate cancer can spread locally into the surrounding tissue or the nearby lymph nodes, called the pelvic nodes. The cancer then can spread even farther (metastasize) to other areas of the body. Symptoms of metastatic disease include fatigue, malaise, and weight loss. The doctor during a rectal examination can sometimes detect local spread into the surrounding tissues. That is, the physician can feel a hard, fixed (not moveable) tumor extending from and beyond the gland. Prostate cancer usually metastasizes first to the lower spine or the pelvic bones (the bones connecting the lower spine to the hips), thereby causing back or pelvic pain. The cancer can then spread to the liver and lungs. Metastases (areas to which the cancer has spread) to the liver can cause pain in the abdomen and jaundice (yellow color of the skin) in rare instances. Metastases to the lungs can cause chest pain and coughing.
Classification
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. 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. 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. 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. 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.
Diagnosis
Most prostate cancer is discovered through routine screening. Still, testing men who have no prostate symptoms for prostate cancer is controversial. Medical organizations don’t agree on the issue of screening and whether it has benefits. Some medical organizations recommend men begin prostate cancer screening in their 50s, or sooner for men who have risk factors for prostate cancer. Other organizations advise against screening. Discuss your particular situation and the benefits and risks of screening with your doctor. Together you can decide whether prostate cancer screening is appropriate for you.
Prostate screening tests might include:
- Digital rectal exam (DRE). During a DRE, your doctor inserts a gloved, lubricated finger into your rectum to examine your prostate, which is adjacent to the rectum. If your doctor finds any abnormalities in the texture, shape or size of your gland, you may need more tests.
- Prostate-specific antigen (PSA) test. A blood sample is drawn from a vein in your arm and analyzed for PSA, a substance that’s naturally produced by your prostate gland. It’s normal for a small amount of PSA to enter your bloodstream. However, if a higher than normal level is found, it may be an indication of prostate infection, inflammation, enlargement or cancer.
PSA testing combined with DRE helps identify prostate cancers at their earliest stages, but studies haven’t proven that these tests save lives. For that reason, there is much debate surrounding prostate cancer screening.
If an abnormality is detected on a DRE or PSA test, your doctor may recommend tests to determine whether you have prostate cancer, such as:
- Ultrasound. If other tests raise concerns, your doctor may use transrectal ultrasound to further evaluate your prostate. A small probe, about the size and shape of a cigar, is inserted into your rectum. The probe uses sound waves to make a picture of your prostate gland.
- Collecting a sample of prostate tissue. If initial test results suggest prostate cancer, your doctor may recommend a procedure to collect a sample of suspicious cells from your prostate (prostate biopsy). Prostate biopsy is often done using a thin needle that’s inserted into the prostate to collect tissue. The tissue sample is analyzed in a laboratory to determine whether cancer cells are present.
Determining whether prostate cancer is aggressive
When a biopsy confirms the presence of cancer, the next step, called grading, is to determine how aggressive the cancer is. The tissue samples are studied, and the cancer cells are compared with healthy prostate cells. The more the cancer cells differ from the healthy cells, the more aggressive the cancer and the more likely it is to spread quickly. More aggressive cancer cells have a higher grade.
The most common scale used to evaluate the grade of prostate cancer cells is called a Gleason score. Scoring can range from 2 (nonaggressive cancer) to 10 (very aggressive cancer).
Determining how far the cancer has spread
Once a cancer diagnosis has been made, your doctor works to determine the extent (stage) of the cancer. Many men won’t require these additional tests. But if your doctor suspects your cancer may have spread beyond your prostate, imaging tests such as these may be recommended:
- Bone scan
- Ultrasound
- Computerized tomography (CT) scan
- Magnetic resonance imaging (MRI)
Once testing is complete, your doctor assigns your cancer a stage. This helps determine your treatment options. The prostate cancer stages are:
- Stage I. This stage signifies very early cancer that’s confined to a microscopic area that your doctor can’t feel.
- Stage II. Your cancer can be felt, but it remains confined to your prostate gland.
- Stage III. Your cancer has spread beyond the prostate to the seminal vesicles or other nearby tissues.
- Stage IV. Your cancer has spread to lymph nodes, bones, lungs or other organs.
Most doctors currently use the 2002 TNM (Tumor, Node, Metastases) staging system for prostate cancer. This is based on a combination of three criteria: extent of the primary tumor (T stage), involvement of lymph nodes by the cancer (N stage), and the presence or absence of spread to distant areas of the body in the form of metastasis (M stage). The TNM 2002 staging system is as follows:
Evaluation of the (primary) tumor (“T”)
- TX: The primary tumor cannot be evaluated.
- T0: There is no evidence of tumor.
- T1: Tumor is present but not detectable clinically or with imaging.
- T1a: Tumor was incidentally found in less than 5% of prostate tissue resected (for other reasons).
- T1b: Tumor was incidentally found in greater than 5% of prostate tissue resected.
- T1c: Tumor was found in a needle biopsy performed due to an elevated serum PSA.
- T2: The tumor can be felt (palpated) on examination but has not spread outside the prostate.
- T2a: The tumor is in half or less than half of one of the prostate gland’s two lobes.
- T2b: The tumor is in more than half of one lobe, but not both.
- T2c: The tumor is in both lobes.
- T3: The tumor has spread through the prostatic capsule (if it is only partway through, it is still T2).
- T3a: The tumor has spread through the capsule on one or both sides.
- T3b: The tumor has invaded one or both seminal vesicles.
- T4: The tumor has invaded other nearby structures.
It should be stressed that the designation “T2c” implies a tumor which is palpable in both lobes of the prostate. Tumors which are found to be bilateral on biopsy only but which are not palpable bilaterally should not be staged as T2c.
Evaluation of the regional lymph nodes (“N”)
- NX: The regional lymph nodes cannot be evaluated.
- N0: There has been no spread to the regional lymph nodes.
- N1: There has been spread to the regional lymph nodes.
Evaluation of distant metastasis (“M”)
- MX: Distant metastasis cannot be evaluated.
- M0: There is no distant metastasis.
- M1: There is distant metastasis.
- M1a: The cancer has spread to lymph nodes beyond the regional ones.
- M1b: The cancer has spread to bone.
- M1c: The cancer has spread to other sites (regardless of bone involvement).
Methods of Treatment
Your prostate cancer treatment options depend on several factors, such as how fast your cancer is growing, how much it has spread, your overall health, as well as the benefits and the potential side effects of the treatment.
Immediate treatment may not be necessary
For men diagnosed with a very early stage prostate cancer, treatment may not be necessary right away. Some men may never need treatment. Instead, doctors sometimes recommend watchful waiting, which is sometimes called active surveillance. In watchful waiting, regular follow-up blood tests, rectal exams and possibly biopsies may be performed to monitor progression of your cancer.
If tests show your cancer is progressing, you may opt for a prostate cancer treatment such as surgery or radiation. Watchful waiting may be an option for cancer that isn’t causing symptoms, is expected to grow very slowly and is confined to a small area of the prostate. Watchful waiting may also be considered for a man who has another serious health condition or an advanced age that makes cancer treatment more difficult. Watchful waiting carries a risk that the cancer may grow and spread between checkups, making it more difficult to treat.
Radiation therapy
Radiation therapy uses high-powered energy to kill cancer cells. Prostate cancer radiation therapy can be delivered in two ways:
- Radiation that comes from outside of your body (external beam radiation). During external beam radiation therapy, you lie on a table while a machine moves around your body, directing high-powered energy beams, such as X-rays, to your prostate cancer. You typically undergo external beam radiation treatments five days a week for several weeks.
- Radiation placed inside your body (brachytherapy). Brachytherapy involves placing many rice-sized radioactive seeds in your prostate tissue. The radioactive seeds deliver a low dose of radiation over a long period of time. Your doctor implants the radioactive seeds in your prostate using a needle guided by ultrasound images. The implanted seeds eventually stop giving off radiation and don’t need to be removed.
Side effects of radiation therapy can include painful urination, frequent urination and urgent urination, as well as rectal symptoms, such as loose stools or pain when passing stools. Erectile dysfunction can also occur.
Hormone therapy
Hormone therapy is treatment to stop your body from producing the male hormone testosterone. Prostate cancer cells rely on testosterone to help them grow. Cutting off the supply of hormones may cause cancer cells to die or to grow more slowly. Hormone therapy options include:
- Medications that stop your body from producing testosterone. Medications known as luteinizing hormone-releasing hormone (LH-RH) agonists prevent the testicles from receiving messages to make testosterone. Drugs typically used in this type of hormone therapy include leuprolide (Lupron, Eligard,), goserelin (Zoladex), triptorelin (Trelstar), histrelin (Vantas) and degarelix (Firmagon).
- Medications that block testosterone from reaching cancer cells. Medications known as anti-androgens prevent testosterone from reaching your cancer cells. Examples include bicalutamide (Casodex), flutamide, and nilutamide (Nilandron). These drugs typically are given along with an LH-RH agonist or given before taking an LH-RH agonist.
- Surgery to remove the testicles (orchiectomy). Removing your testicles reduces testosterone levels in your body. The effectiveness of orchiectomy in lowering testosterone levels is similar to that of hormone therapy medications, but orchiectomy may lower testosterone levels more quickly.
Hormone therapy is used in men with advanced prostate cancer to shrink the cancer and slow the growth of tumors. In men with early-stage prostate cancer, hormone therapy may be used to shrink tumors before radiation therapy. This can make it more likely that radiation therapy will be successful. Hormone therapy is sometimes used after surgery or radiation therapy to slow the growth of any cancer cells left behind.
Side effects of hormone therapy may include erectile dysfunction, hot flashes, loss of muscle and bone mass, reduced sex drive, and weight gain. Hormone therapy also increases the risk of heart disease and heart attack. Doctors believe long-term use of hormone therapy and the low hormone levels that result may lead to cardiovascular problems.
Surgery to remove the prostate
Surgery for prostate cancer involves removing the prostate gland (radical prostatectomy), some surrounding tissue and a few lymph nodes. Ways the radical prostatectomy procedure can be performed include:
- Making an incision in your abdomen. During retropubic surgery, the prostate gland is taken out through an incision in your lower abdomen. Compared with other types of prostate surgery, retropubic prostate surgery may carry a lower risk of nerve damage, which can lead to problems with bladder control and erections.
- Making an incision between your anus and scrotum. Perineal surgery involves making an incision between your anus and scrotum in order to access your prostate. The perineal approach to surgery may allow for quicker recovery times, but this technique makes removing the nearby lymph nodes and avoiding nerve damage more difficult.
- Laparoscopic prostatectomy. During a laparoscopic radical prostatectomy, several small incisions are made in the abdomen. The doctor inserts special surgical tools through the incisions, including a long, slender tube with a small camera on the end (laparoscope). The laparoscope sends images to a monitor in the operating room. The surgeon watches the monitor as he or she guides the instruments. Laparoscopic surgery may offer a shorter hospital stay and quicker recovery than traditional surgery.
- Using a robot to assist with surgery. During robotic laparoscopic surgery, the instruments are attached to a mechanical device (robot). The surgeon sits at a console and uses hand controls to guide the robot to move the instruments. Using a robot during laparoscopic surgery may allow the surgeon to make more precise movements with surgical tools than is possible with traditional laparoscopic surgery. Discuss with your doctor which type of surgery is best for your specific situation.
Radical prostatectomy carries a risk of urinary incontinence and erectile dysfunction. Ask your doctor to explain the risks you may face based on your situation, the type of procedure you select, your age, your body type and your overall health.
Freezing prostate tissue
Cryosurgery or cryoablation involves freezing tissue to kill cancer cells. During cryosurgery for prostate cancer, small needles are inserted in the prostate using ultrasound images as guidance. A very cold gas is placed in the needles, which causes the surrounding tissue to freeze. A second gas is then placed in the needles to reheat the tissue. The cycles of freezing and thawing kill the cancer cells and some surrounding healthy tissue. Original attempts to use cryosurgery for prostate cancer resulted in unacceptable side effects. Doctors hope newer technologies will make cryosurgery safer.
Heating prostate tissue using ultrasound
High-intensity focused ultrasound treatment uses powerful sound waves to heat prostate tissue, causing cancer cells to die. High-intensity focused ultrasound is done by inserting a small probe in your rectum. The probe focuses ultrasound energy at precise points in your prostate. High-intensity focused ultrasound treatments are being studied in clinical trials. More study is needed to understand the benefits and risks of this treatment.
Chemotherapy
Chemotherapy uses drugs to kill rapidly growing cells, including cancer cells. Chemotherapy can be administered through a vein in your arm, in pill form or both. Chemotherapy may be a treatment option for men with prostate cancer that has spread to distant areas of their bodies. Chemotherapy may also be an option for cancers that don’t respond to hormone therapy. Doctors are studying whether chemotherapy is helpful when combined with radiation therapy or surgery.
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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 (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.) 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. In Japan, death from prostate cancer was one-fifth to one-half the rates in the United States and Europe in the 1990s. In India in the 1990s, half of the people with prostate cancer confined to the prostate died within ten years. African-American men have 50–60 times more prostate cancer and prostate cancer deaths than men in Shanghai, China. In Nigeria, two percent of men develop prostate cancer and 64% of them are dead after two years.
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.
In 1941, Charles Huggins reported that androgen ablation therapy causes regression of primary and metastatic androgen-dependent prostate cancer. 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. 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.
Classification systems
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 by 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; the SEARCH registry, representing data from several Veterans Administration and active military medical centers; a multi-institutional cohort in Germany; and the prostatectomy cohort at Johns Hopkins University. More recently, it has been shown to predict metastasis and mortality following prostatectomy, radiation therapy, watchful waiting, or androgen deprivation therapy.
Prevention
No specific measures are known to prevent the development of prostate cancer. At present, therefore, we can hope only to prevent progression of the cancer by making early diagnoses and then attempting to cure the disease. Early diagnoses can be made by screening men for prostate cancer with PSA and digital rectal examination The purpose of the screening is to detect early, tiny, or even microscopic cancers that are confined to the prostate gland. Early treatment of these malignancies (cancers) can stop the growth, prevent the spread, and possibly cure the cancer.
Based on some research in animals and people, certain dietary measures have been suggested to prevent the progression of prostate cancer. For example, low-fat diets, particularly avoiding red meats, have been suggested because they are thought to slow down the growth of prostate tumors in a manner not yet known. Soybean products, which work by decreasing the amount of testosterone circulating in the blood, also reportedly can inhibit the growth of prostate tumors. Finally, other studies show that tomato products (lycopenes), the mineral selenium, and vitamin E might slow the growth of prostate tumors in ways that are not yet understood.
Recently, studies have shown that certain medications (finasteride [Propecia] and dutasteride [Avodart]) decrease the chances of getting prostate cancer when taken over the long term. These medications are currently used for shrinking the size of the prostate and relieving symptoms associated with benign (non-cancerous) enlargement of the prostate. However, they may have a future role for decreasing the chances of development of prostate cancer in men who are at high risk for the disease.