Prostate CancerLast Updated: October 07, 2009 This section has been reviewed and approved by the Cancer.Net Editorial Board, 09/09 Overview
Cancer begins when normal cells in the prostate begin to change and grow uncontrollably, forming a mass called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body). Prostate cancer is a malignant tumor that begins in the prostate gland of men. The prostate is a walnut-sized gland located behind the base of the penis, in front of the rectum, and below the bladder. It surrounds the urethra, the tube-like channel that carries urine and semen through the penis. The prostate's main function is to produce seminal fluid, the liquid in semen that protects, supports, and helps transport sperm. Some prostate cancers grow very slowly and may not cause symptoms or problems for years. In this situation, the cause of death is usually not from prostate cancer, but other causes. However, if cancer does metastasize (spread) to other parts of the body, it can cause pain, fatigue, and other symptoms. Prostate cancer is somewhat unusual from other types of cancer, in that many tumors that are diagnosed do not spread from the prostate. And often, even metastatic prostate cancer can be successfully treated, with the person surviving in good health for some years. More than 95% of prostate cancers are adenocarcinomas, cancer that develops in glandular tissue. A rare type of prostate cancer known as neuroendocrine cancer or small cell anaplastic cancer tends to spread earlier, but usually does not produce prostate-specific antigen (PSA), a tumor marker discussed later in this section. Read more about neuroendocrine tumors. Statistics Prostate cancer is the most common cancer among men. In 2009, an estimated 192,280 men in the United States will be diagnosed with prostate cancer. It is estimated that 27,360 deaths from this disease will occur this year. Prostate cancer is the second leading cause of cancer death in men. Although the number of deaths from prostate cancer is declining among all men, the death rate remains more than twice as high in black men than in white men. More than 90% of all prostate cancer cases are discovered when the disease is limited to the prostate and surrounding organs. In these cases, nearly 100% of men are expected to live at least five years after diagnosis. The five-year relative survival rate (the percentage of people who survive after the cancer is detected, excluding those who die from other diseases) of men with prostate cancer is 99%. The 10-year and 15-year relative survival rates are 93% and 79%, respectively. Cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a man how long he will live with prostate cancer. Because survival statistics are often measured in multi-year intervals, they may not represent advances made in the treatment or diagnosis of this cancer. Statistics adapted from the American Cancer Society's publication, Cancer Facts & Figures 2009. Find out more about basic cancer terms used in this section. Medical Illustrations
Risk Factors and Prevention
A risk factor is anything that increases a person’s chance of developing a disease, including cancer. Some risk factors can be controlled, such as smoking, and some cannot be controlled, such as age and family history. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and communicating them to your doctor may help you make more informed lifestyle and health care choices. Because the exact cause of prostate cancer is still unknown, it is also unknown how to prevent prostate cancer. The following factors can raise a man’s risk of developing prostate cancer: Age. The risk of prostate cancer increases with age, rising rapidly after age 50. More than 80% of prostate cancers are diagnosed in men who are 65 or older. Race/ethnicity. African American men are at higher risk for prostate cancer than white men. They are more likely to develop prostate cancer at an earlier age and to have aggressive tumors that grow quickly. The precise reasons for these differences are not known and probably involve both biologic and socioeconomic factors. Some scientists believe that a high-fat diet, which can be common in many parts of the African American community, plays a role in the development of prostate cancer (see the Diet heading below for more details). It may also be due to genetic factors within the African American community, but the specific genes are not known. Prostate cancer occurs most often in North America and northern Europe and is less common in Asia, Africa, and Latin America. Of importance, it appears that its frequency is increasing in Asian populations living in urbanized environments, such as Hong Kong, Singapore, and North American and European cities. Family history. A man who has a father or brother with prostate cancer has a higher risk of developing the disease than a man who does not. Researchers have discovered specific genes that may possibly be associated with prostate cancer, although these have not yet been shown to cause prostate cancer or to be specific to this disease. Learn more about The Genetics of Prostate Cancer. Diet. No study has shown conclusively that diet and nutrition can directly influence the development of prostate cancer, but many studies indicate there may be a link. There is not enough information yet to make clear recommendations about the role diet plays in prostate cancer, but the following may be helpful:
Viruses. Researchers have discovered a virus called xenotropic murine leukemia virus (XMRV) in tissue from some men with prostate cancer. Men infected with this virus may be more likely to develop prostate cancer, but more studies are needed to understand the role of XMRV in prostate cancer. Hormones and chemoprevention. High levels of testosterone (a male sex hormone) may speed up or cause the development of prostate cancer. For instance, prostate cancer does not develop in men whose bodies no longer make testosterone, and stopping the body’s production of testosterone, called androgen deprivation therapy, often treats advanced prostate cancer. A class of drugs called 5-alpha-reductase inhibitors (5-ARIs) that include finasteride (Proscar, Propecia) and dutasteride (Avodart) may lower a man’s risk of prostate cancer. In clinical trials, both drugs lowered the risk of prostate cancer. Initially, one of these trials suggested that a very small percentage of men who took finasteride had a higher risk of developing a more aggressive type of prostate cancer than the patients who did not receive finasteride. With further review, it now seems that finasteride causes the prostate gland to shrink, which may have allowed the doctors to find these sections of more aggressive cancers in the post-treatment biopsies (tissue removed for further examination). But, the data reviews are ongoing and these drugs have not been approved yet for prostate cancer prevention by the U.S. Food and Drug Administration (FDA). Learn what to know about ASCO’s guideline on finasteride for prostate cancer prevention. Prostate cancer screening Screening for prostate cancer is done to find evidence of cancer in otherwise healthy men. Two tests are used to screen for prostate cancer: the prostate-specific antigen (PSA) test and digital rectal examination (DRE, a test where the doctor inserts a gloved, lubricated finger into a man's rectum and feels the surface of the prostate for any irregularities). PSA is found in higher-than-normal levels in men with various conditions of the prostate, including benign prostatic hyperplasia (BPH, an enlarged prostate), inflammation of the prostate, and prostate cancer. There is controversy about using the PSA test as a screening test for large numbers of men with no symptoms of prostate cancer. On one hand, the PSA test is useful for detecting early prostate cancer, which helps men get the treatment they need before the cancer has spread. On the other hand, PSA screening has not yet proven to lower death rates from prostate cancer, detects conditions that are not cancer, and misses some prostate cancers. Unlike other types of cancer, prostate cancer grows slowly in many men—so slowly that in some men it would not threaten their life even if not treated. Because of this, screening for prostate cancer may mean that some men have surgery and other treatments that may not ever be needed. For this reason, many men and their doctors may consider active surveillance (watchful waiting; see Treatment) of their cancer rather than immediate treatment. Because prostate cancer treatments have significant side effects, treating it unnecessarily may seriously affect a man's quality of life, including impotence (inability to get an erection) and incontinence (inability to control urine flow). However, it is important to note that it is not easy to predict which tumors will behave aggressively and which will grow slowly. This has led some doctors to believe that it is prudent to use relatively safe screening tests, such as the PSA test, to detect aggressive cases early, even if it means that some patients will receive unnecessary treatment. Two major clinical trials have reported results on prostate cancer screening. In the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, researchers found more cancers with screening, but they also found no differences in deaths from prostate cancer in men who were screened with PSA and DRE compared with men who were not screened up to 11 years after the screening began. In the European Randomized Study of Screening for Prostate Cancer (ERSPC) trial, researchers saw a small reduction in prostate cancer deaths of men who were screened for prostate cancer (7 deaths per 10,000 men screened), but the overall survival was the same in the two groups. Until there is more complete research to evaluate this issue, ASCO does not have an official statement about prostate cancer screening. Every man should discuss his individual situation and risk level with his doctor and work together to make a decision. However, no study definitely proves that screening is more beneficial for men at higher risk of prostate cancer, or for African American men versus white men. In addition, men older than 75 may not need screening. Read about talking with your doctor about PSA screening. Symptoms
Often, prostate cancer is discovered through a PSA test or DRE (see Risk Factors and Prevention) in otherwise healthy men who have not had any symptoms. When prostate cancer does cause symptoms, the following symptoms may occur. Sometimes, men with prostate cancer do not show any of these symptoms. Or, these symptoms may be caused by a medical condition that is not cancer. If you are concerned about a symptom on this list, please talk with your doctor.
None of these symptoms is specific to prostate cancer, and the absence of symptoms does not mean that a man does not have prostate cancer. The same symptoms occur in men who have a noncancerous condition known as BPH, or enlarged prostate. Urinary symptoms also can indicate an infection or other conditions. If cancer has spread beyond the prostate gland, a man may experience:
Diagnosis
Doctors use many tests to diagnose cancer and determine if it has metastasized. Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis, but this situation occurs infrequently with prostate cancer. For example, this occurs when a patient has another medical problem that makes it difficult to carry out a biopsy, or when a person has a very high PSA level and a bone scan that indicates cancer. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:
In addition to a physical examination, the following tests may be used to diagnose prostate cancer: PSA test. As described in Risk Factors and Prevention, PSA is a type of protein released by prostate tissue found in higher levels in a man's blood when there is abnormal activity in the prostate, including prostate cancer, BPH, or inflammation of the prostate. Doctors can look at features of the PSA value, such as absolute level, change over time, and level in relation to prostate size, to determine if a biopsy is needed. In addition, a version of the PSA test allows the doctor to measure a specific component, called the “free” PSA, which can sometimes help determine if a tumor is benign (noncancerous) or malignant. DRE. This test is used to find irregularities in the prostate (see Risk Factors and Prevention). It is not very precise; therefore, most men with early prostate cancer have a normal DRE test. If the PSA or DRE test results are abnormal, the following tests can confirm a diagnosis of cancer: Transrectal ultrasound (TRUS). A doctor inserts a probe into the rectum that takes a picture of the prostate using sound waves that bounce off the prostate. Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. To get a tissue sample, most often a surgeon uses TRUS and a biopsy tool to take very small slivers of prostate tissue. The sample removed with the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). This procedure is usually performed as an outpatient procedure, and the patient is given local anesthesia beforehand to numb the area. To determine if cancer has spread beyond the prostate, doctors may perform the following imaging tests: Bone scan. A bone scan uses a radioactive tracer to look at the inside of the bones. The tracer is injected into a patient’s vein. It collects in areas of the bone and is detected by a special camera. Healthy bone appears gray to the camera, and areas of injury, such as those caused by cancer, appear dark. Computed tomography (CT or CAT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein to provide better detail. Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium may be injected into a patient’s vein to create a clearer picture. Learn more about what to expect when having common tests, procedures, and scans. Find out more about common terms used during a diagnosis of cancer. Staging With Illustrations
Staging is a way of describing a cancer, such as where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis (chance of recovery). There are different stage descriptions for different types of cancer. There are two types of staging for prostate cancer. First, the clinical stage is based on the results of tests done before surgery, such as a biopsy, x-rays, CT scans, and bone scans. (X-rays, bone scans, and CT scans may not be necessary; they are recommended based on the level of serum PSA, the grade and volume of the cancer, and the clinical stage of the cancer.) Then, the pathologic stage is based on information found during surgery, plus the laboratory results (pathology) of the prostate tissue removed during surgery (which often includes the removal of the entire prostate and some lymph nodes). One tool that doctors use to describe the stage is the TNM system. This system uses three criteria to judge the stage of the cancer: the tumor itself, the lymph nodes around the tumor, and if the tumor has spread to other parts of the body. The results are combined to determine the stage of cancer for each person. There are four stages: stages I through IV (one through four). The stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments. After gathering information with the TNM method, the results can be grouped together into a simpler set of stages (called stage grouping). Many doctors do not use the TNM system and prefer another method called the Jewett-Whitmore staging system (stages A, B, C, and D). Both are described below. Staging for prostate cancer involves reviewing test results to determine if the cancer has spread from the prostate to other parts of the body. The cancer is also given a grade (G), which is based on its appearance under a microscope, according to how much the cancer resembles healthy tissue. TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:
Tumor. Using the TNM system, the "T" plus a letter or number (0 to 4) is used to describe the size and location of the tumor. Some stages are also divided into smaller groups that help describe the tumor in even more detail. Specific tumor stage information, based on the classification system that was implemented in 2002, is listed below. TX: The primary tumor cannot be evaluated. T0: There is no evidence of tumor in the prostate. T1: The tumor cannot be felt during the DRE and is not seen during imaging (any test that produces pictures of the inside of the body, such as a CT scan). It may be found when surgery is done for another reason, usually for BPH, or abnormal growth of benign prostate cells. T1a: The tumor is in 5% or less of the prostate tissue removed through surgery. T1b: The tumor is in more than 5% of the prostate tissue removed through surgery. T1c: The tumor is found during a needle biopsy, usually because the patient has an elevated PSA level. T2: The tumor is found only within the prostate, not other areas of the body. It is large enough to be felt during the DRE. T2a: The tumor has invaded one-half of one lobe (part or side) of the prostate. T2b: The tumor has spread to more than one-half of one lobe of the prostate, but not to both lobes. T2c: The tumor has invaded both lobes of the prostate. T3: The tumor extends through the prostate capsule (into the tissue just outside the prostate on one side). T3a: The tumor extends through the prostate capsule either unilaterally (on one side) or bilaterally (on both sides of the prostate). T3b: The tumor has invaded the seminal vesicle(s), the tube(s) that carry semen. T4: The tumor is fixed, or it is invading nearby structures besides the seminal vesicles, such as the neck of the bladder, the external sphincter (part of the body that helps to control urination), the rectum, levator muscles, and/or the pelvic wall. Nodes. The “N” in the TNM staging system stands for lymph nodes, the tiny, bean-shaped organs that help fight infection. Lymph nodes near the prostate in the pelvic region are called regional lymph nodes. Lymph nodes in other parts of the body are called distant lymph nodes. NX: The regional lymph nodes cannot be evaluated. N0: There is no regional lymph node metastasis. N1: The prostate cancer has invaded the regional lymph node(s). Distant metastasis. The "M" in the TNM system indicates whether the prostate cancer has spread to other parts of the body (to areas such as the lungs or the bones). MX: Distant metastasis cannot be evaluated. M0: The disease has not metastasized. M1: There is distant metastasis. M1a: The cancer has invaded nonregional, or distant, lymph node(s). M1b: The cancer has invaded bone(s) in the body. M1c: The cancer has reached another part of the body. Grade. Doctors may also use the term “grade,” which describes how much the tumor appears like healthy tissue. The grade of a cancer can help the doctor to predict how quickly the cancer might grow. In cancer that resembles healthy tissue, doctors can clearly see different types of cells grouped together (called well differentiated). In a higher-grade cancer, the cancer cells usually look less like healthy cells, or “wilder” (called poorly differentiated or undifferentiated). In general, tumors with more differentiated cells have a better prognosis. The Gleason System is the most common prostate cancer grading system used. This method looks at how the cancer cells are arranged in the prostate and grades them based on a scale of 1 to 5. The doctor looks for a pattern of cell growth, and adds the score to come up with an overall score. The interpretation of the Gleason score by physicians has changed in recent years. Originally, there was a broader spread, with physicians using a range of scores. Today, doctors tend to describe a score of 6 is a low-grade cancer, 7 is medium-grade, and a score of 8, 9, or 10 is high-grade cancer. A lower-grade cancer grows more slowly and is less likely to spread than a cancer with a higher grade. The TNM system uses the letter "G" to define a grade for prostate cancer. GX: The grade cannot be evaluated. G1: The cells are well-differentiated (Gleason 6 or less). G2: The cells are moderately differentiated (Gleason 7). G3: The cells are poorly differentiated or undifferentiated (Gleason 8 to 10). Cancer stage grouping. Doctors assign the stage of the cancer by combining the T, N, and M classification and the grade. As mentioned above, some doctors prefer to use the Jewett-Whitmore staging system (stages A, B, C, and D). Stage I or Stage A: Cancer is found in the prostate only, usually during another medical procedure. It cannot be felt during the DRE. A stage I cancer usually contains well-differentiated cells and is predicted to grow slowly. This can also be called stage A1 prostate cancer when it affects only one lobe of the prostate and stage A2 when both prostate lobes are involved (T1a, N0, M0, G1).Stage II or Stage B: The doctor can feel the tumor during a DRE. There is no evidence that it has spread beyond the prostate gland, but the cells are usually more abnormal and may tend to grow more quickly. (It has not spread to lymph nodes or distant organs.) Stage II prostate cancer may also be called stage A2, stage B1, or stage B2 prostate cancer (T1, T2, T3; N0; M0; any G). Stage III or Stage C: The cancer has spread beyond the outer layer of the prostate into nearby tissues. It may also have spread to the seminal vesicles, the glands in men that help produce semen (T3, N0, M0, any G). Stage IV or Stage D: This describes any tumor of any grade (any G) that has spread to other areas of the body such as the bladder or rectum (T4, N0, M0); bone, liver, lungs (any T, N0, M1); or lymph nodes (any T, N1, M0). Stage IV prostate cancer may also be called stage D1 or D2 prostate cancer. Recurrent: Recurrent prostate cancer is cancer that comes back after treatment. It may come back in the prostate area again or in other parts of the body. Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Sixth Edition (2002) published by Springer-Verlag New York, www.cancerstaging.net. Treatment
The treatment of prostate cancer depends on the size and location of the tumor, whether the cancer has spread, and the man’s overall health. In many cases, a team of doctors will work with the patient to determine the best treatment plan. This section outlines treatments that are the standard of care (the best treatments available) for this specific type of cancer. Patients are also encouraged to consider clinical trials when making treatment plan decisions. A clinical trial is a research study to test a new treatment to prove it is safe, effective, and possibly better than standard treatment. Your doctor can help you review all treatment options. For more information, read the Clinical Trials section. It is important to discuss the goals and possible side effects of treatment with your doctor before treatment begins, including the likelihood of success of that treatment, the potential side effects of therapy (including possible urinary, bowel, sexual, and hormone-related side effects), and the patient’s preferences. Men should talk with their doctor about how the various treatments affect recurrence (the return of the cancer after treatment), survival, and quality of life. In addition, the success of any treatment often depends on the skill and expertise of the physician or surgeon, so it is important to find doctors who have experience treating prostate cancer. Descriptions of the most common treatment options for prostate cancer are listed below. Active surveillance (watchful waiting), for early-stage cancer If a prostate cancer is in an early stage, growing slowly, and if treating the cancer would cause more discomfort than the disease itself, a doctor may recommend watchful waiting, also called active surveillance or watch-and-wait. The cancer is monitored closely with periodic PSA testing, DRE tests, and watching for symptoms. Treatment would begin only when the tumor shows signs of becoming more aggressive or spreading, causes pain, or obstructs the urinary tract. This approach may be taken in much older patients, those with other serious or life-threatening illnesses, or those who wish to delay active treatment because of potential side effects. However, real caution must be taken not to make errors of judgment about the disease. In other words, doctors must collect as much information as possible about the patient’s other illnesses and potential life expectancy, so they don’t miss the chance to detect an early, aggressive prostate cancer. New information is becoming available all the time, and it is important for men to discuss these issues with their doctor to make the best decision about treatment. Surgery Surgery is used to try to cure cancer before it has spread outside the prostate. A surgical oncologist is a doctor who specializes in treating cancer using surgery; for prostate cancer, a urologist or urologic oncologist is the surgical oncologist involved in treatment. The type of surgery depends on the stage of the disease, the man’s general health, and other factors. Radical (open) prostatectomy. A radical prostatectomy involves surgical removal of the whole prostate and accompanying seminal vesicles; lymph nodes in the pelvic area may also be removed . This operation has the risk of interfering with sexual potency. Nerve-sparing surgery, when possible, increases the chances that a man will remain sexually potent after surgery by avoiding surgical damage to the nerves that allow erections and orgasm to occur. Orgasm can occur even if some nerves are cut; these are two separate processes. Urinary incontinence (inability to control urine flow) is also a possible complication of prostatectomy. To help resume normal sexual function, men can receive drugs, penile implants, or injections. Sometimes, additional surgery can fix the complication of urinary incontinence. Laparoscopic prostatectomy (with or without robotic assistance). This type of surgery is potentially much less invasive than an open radical prostatectomy and may potentially reduce recovery time. A camera and instruments are inserted through small, keyhole incision in the patient’s abdomen. The surgeon then directs the robotic instruments (if robotic assistance is being used) to remove the prostate gland and surrounding tissue. In general, laparoscopic prostatectomy has less bleeding and less pain, but sexual and urinary side effects can be similar to an open radical prostatectomy. This procedure has not been available for as long a time as open radical prostatectomy, so longer-term follow-up information, including permanent cure rates, are not yet certain. This procedure remains controversial among some specialists. As noted, more follow-up data are needed. Talk with your doctor about whether your treatment center offers this procedure and how it compares with the results to the conventional open radical prostatectomy. Transurethral resection of the prostate (TURP). TURP is most often used to relieve symptoms of urinary obstruction, not to cure cancer. In this procedure, under a full anesthetic, a surgeon inserts a cystoscope (a narrow tube with a cutting device) into the urethra and into the prostate to remove prostate tissue. This is rarely used to treat prostate cancer in current clinical practice. Cryosurgery. This procedure is commonly used for investigational studies. Cryosurgery (also called cryotherapy or cryoablation) involves freezing cancer cells with a metal probe inserted through a small incision in the area between the rectum and the scrotum, the skin sac that contains the testicles. Cryosurgery may be useful for early-stage cancer and for men who cannot have a radical prostatectomy. A common side effect of cryosurgery is impotence, so this approach is not recommended for men who desire to preserve their sexual function. Another complication may be the development of fistulae (holes between the prostate and the bowel), although this complication appears to occur much less frequently with the development of newer cryosurgery techniques. Learn more about cancer surgery. Radiation therapy Radiation therapy is the use of high-energy rays to kill cancer cells. Radiation therapy may be given externally, called external-beam radiation therapy, in which radiation is given from a machine outside the body, or internally, where a radioactive substance or seeds are placed inside the prostate, near the tumor. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. Radiation therapy can be useful at all stages of localized cancer. It is also used to relieve symptoms, such as pain, for patients with advanced or metastatic cancer. Several treatments or “fractions” may be needed. External-beam radiation therapy. External-beam radiation therapy focuses a beam of radiation on the area affected by cancer. Some cancer centers use conformal radiation therapy (CRT), where computers help precisely map the location and shape of the cancer. CRT reduces radiation exposure to healthy tissues and organs around the tumor by directing the radiation therapy beam from different directions with the intention of focusing the dose on the area of the tumor. Intensity-modulated radiation therapy (IMRT). IMRT is a form of three-dimensional (3-D) CRT. CRT uses CT scans to form a 3-D picture of the prostate before treatment. IMRT enables high doses to be delivered to the prostate without increasing the risk of exposure to nearby organs. Brachytherapy. Brachytherapy involves insertion of radioactive sources directly into the prostate. These sources (called seeds) give off localized radiation and may be used for hours (high-dose rate) or for weeks (low-dose rate). Low-dose rate seeds are left in the prostate permanently, even after all the radioactive material has been used up. Radiation therapy may cause such side effects as diarrhea or other disruption of bowel function; increased urinary urge or frequency; fatigue; impotence; and rectal discomfort, burning, or pain. These side effects usually go away after treatment. Learn more about radiation therapy. Hormone therapy Because prostate cancer growth is driven by male sex hormones known as androgens, reducing levels of these hormones can help slow the growth of the cancer. Hormone treatment is also called androgen ablation or androgen deprivation therapy. The most common androgen is testosterone. The production of testosterone can be reduced either surgically, with surgical castration (removal of the testicles), or with drugs that turn off the function of the testicles (see below). Hormone therapy is used to treat prostate cancer that has continued to grow after surgery and radiation therapy, or when it is widespread at the time of diagnosis. More recently, hormone therapy has also been used with radiation therapy for men with a cancer at a higher risk for recurrence. In some men, hormone therapy will be used first to shrink a prostate cancer tumor before radiation therapy or surgery. In some men with prostate cancer that has spread locally (and identified during a radical prostatectomy), hormone therapy is given after the surgery for two to three years as adjuvant therapy (treatment that is given after the first treatment). Traditionally, hormone therapy was used until it stopped controlling the cancer. Then the cancer was said to be hormone refractory (meaning that the hormone therapy has stopped working), and other options were considered. Recently, researchers have begun studying intermittent hormone therapy, which is hormone therapy that is given for specified periods and then discontinued temporarily according to a schedule. Giving hormones in this way appears to lower the symptoms of this therapy. In addition, intermittent hormone therapy may possibly maintain hormone responsiveness for a longer time than standard (continuous) hormone treatment; this concept is currently being tested in clinical trials. One important complication of hormonal therapy is the risk of developing metabolic syndrome. Metabolic syndrome refers to a set of conditions, such as high levels of blood cholesterol and high blood pressure that place a person at high risk of heart disease, stroke, and diabetes. At present, it is not certain how often is occurs, nor the exact mechanism, but it is quite clear that patients who undergo a surgical or medical castration with hormone therapy (even a temporary medical castration) are at increased risk for developing metabolic syndrome. The risks and benefits of castration should be carefully discussed with your doctor. For men with metastatic prostate cancer, especially if it is advanced and causing symptoms, most doctors believe that the benefits of castration far outweigh the risks of metabolic syndrome. Types of hormone therapy Bilateral orchiectomy. Bilateral orchiectomy involves surgical removal of both testicles. Even though this is surgery, it is called a hormone treatment because it removes the main source of testosterone production, the testicles. This surgery is permanent and cannot be reversed. LHRH agonists. LHRH stands for luteinizing hormone-releasing hormone. LHRH agonists are drugs that reduce the body's production of testosterone by interfering with hormonal control mechanisms within the brain, which control the functioning of the testicles. Anti-androgens. While LHRH agonists lower testosterone levels in the blood, anti-androgens block testosterone from binding to so-called “androgen receptors,” chemical structures in the cancer cells that allow testosterone and other male hormones to enter the cells. LHRH antagonist. This type of drug, also called a gonadotropin-releasing hormone (GnRH) antagonist, stops the testicles from producing testosterone by mimicking the action of LHRH. The FDA has approved one drug, degarelix (Firmagon), given by injection, to treat advanced prostate cancer. This drug may cause a severe allergic reaction. Female hormones. Estrogen can lower testosterone levels. When this drug is given as a pill, side effects can include heart problems and blood clots. More recently, estrogens have been administered as injections or as skin patches, and this type of treatment may be associated with a lower chance of heart and clotting side effects. Combined androgen blockade. Sometimes, LHRH agonists are used in combination with peripheral-blocking drugs, such as anti-androgens, to more completely inhibit male hormones. Many doctors feel that this combined approach is the safest way to start hormone treatment, as this prevents a potential flare-up or increase in activity of the prostate cancer cells that sometimes occurs as a result of a temporary surge in testosterone production by the testicles (in response to the LHRH agonists). Major clinical trials have not shown a big difference in long-term survival results from the use of combined androgen blockade as permanent therapy; therefore, some doctors prefer to give combined drug treatment only for the first two to three months. Hormone therapy may cause significant side effects. Side effects generally go away after hormone treatment is finished, except in men who have had an orchiectomy. Patients may experience impotence, loss of libido (sexual desire), hot flashes, gynecomastia (enlarged breasts), and osteoporosis (weakening bones). Men who have received LHRH agonists for more than two years will frequently have ongoing hormonal effects, even if the drugs are no longer given. Chemotherapy Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. Chemotherapy is given by a medical oncologist, a doctor who specializes in treating cancer with medication. Some people may receive chemotherapy in their doctor's office; others may go to the hospital. A chemotherapy regimen (schedule) usually consists of a specific number of cycles given over a specific time. The side effects of chemotherapy depend on the individual and the dose used, but can include fatigue, risk of infection, nausea and vomiting, loss of appetite, and diarrhea. These side effects usually go away once treatment is finished. Chemotherapy can be taken orally (by mouth) or intravenously (injected into a vein), and it may help patients with advanced or hormone-refractory prostate cancer. There is no standard chemotherapy for use against prostate cancer, but a number of clinical trials are exploring chemotherapy for advanced prostate cancer. The most popular, current approach involves the use of a drug called docetaxel (Taxotere) given in conjunction with a steroid called prednisone (multiple brand names). This combination has been shown to help men with advanced prostate cancer live longer than another chemotherapy, mitoxantrone (Novantrone), which is most useful for controlling prostate cancer symptoms. The FDA has approved the drugs mitoxantrone and docetaxel for use in men with prostate cancer that is resistant to hormone therapy. Also, the drugs paclitaxel (Taxol) and estramustine (Estracyt) have shown some beneficial effects in treating advanced prostate cancer. Estramustine is being used less often in current clinical practice because of its side effects, which includes an increased risk of blood clots. Although clinical trials have shown that docetaxel prolongs survival and has a higher rate of remission than mitoxantrone, the difference in survival is only an average of a few additional months, and the side effects of mitoxantrone are generally milder than for docetaxel. Many new medications for prostate cancer are in development and may be available in clinical trials. Learn more about chemotherapy and preparing for treatment. The medications used to treat cancer are continually being evaluated. Talking with your doctor is often the best way to learn about the medications prescribed for you, their purpose, and their potential side effects or interactions with other medications. Learn more about your prescriptions by using searchable drug databases. Advanced prostate cancer Prostate cancer that develops the ability to grow without the presence of male sex hormones, and causes hormone treatments to stop working, is called androgen-independent cancer, or hormone-refractory prostate cancer. Although there is no cure for this type of cancer, it is often treatable with radiation therapy or chemotherapy. If all treatments have failed to control prostate cancer, or if cancer comes back after treatment, a patient may experience pain, fatigue, and weight loss. At this point, the goal of treatment switches from curing the cancer to slowing it down and relieving symptoms. It is important to note that many men outlive their prostate cancer, even those with advanced disease. Often, the prostate cancer grows slowly, and there are now effective treatment options that extend life even further. A few drugs can help treat the symptoms of advanced cancer. Chemotherapy (see above). Chemotherapy is most commonly used for patients with advanced, hormone-refractory prostate cancer. It can be effective in relieving symptoms, such as pain, weight loss, and fatigue, and may prolong life for some patients. Strontium and samarium. Given by injection, these radioactive agents are absorbed near the area of bone pain. The radiation that is released helps relieve the pain, probably by causing local tumor shrinkage. Pamidronate (Aredia) and zoledronic acid (Zometa). Given by injection, these drugs reduce the level of calcium in the blood and cause a reduction of bone complications (such as pain, fracture, need for surgery) due to metastases. A high calcium level is called hypercalcemia and is sometimes present in men with advanced prostate cancer. Hormone therapy. Some types of hormone therapy may be used to treat advanced cancer (see above). Read more about hormone therapy for advanced prostate cancer. Find out more about common terms used during cancer treatment. Clinical Trials Resources
Doctors and scientists are always looking for better ways to treat patients with prostate cancer. A clinical trial is a way to test a new treatment to prove that it is safe, effective, and possibly better than a standard treatment. The clinical trial may be evaluating a new drug, a new combination of existing treatments, a new approach to radiation therapy or surgery, or a new method of treatment or prevention. Patients who participate in clinical trials are among the first to receive new treatments before they are widely available. However, there is no guarantee that the new treatment will be safe, effective, or better than a standard treatment. Patients decide to participate in clinical trials for many reasons. For some patients, a clinical trial is the best treatment option available. Because standard treatments are not perfect, patients are often willing to face the added uncertainty of a clinical trial in the hope of a better result. Other patients volunteer for clinical trials because they know that finding new drugs and other therapies is the only way to make progress in treating prostate cancer. Even if they do not benefit directly from the clinical trial, their participation may benefit future men with prostate cancer. Sometimes people have concerns that, by participating in a clinical trial, they may receive no treatment by being given a placebo or a “sugar pill”. The use of placebos in cancer clinical trials is rare. When a placebo is used in a study, it is done with the full knowledge of the participants. Find out more about placebos in cancer clinical trials. To join a clinical trial, patients participate in a process known as informed consent. During informed consent, the doctor should list all of the patient’s options, so the person understands how the new treatment differs from the standard treatment. The doctor must also list all of the risks of the new treatment, which may or may not be different from the risks of standard treatment. Finally, the doctor must explain what will be required of each patient in order to participate in the clinical trial, including the number of doctor visits, tests, and the schedule of treatment. Learn more about Clinical Trials, including patient safety, phases of a clinical trial, deciding to participate in a clinical trial, questions to ask the research team, and links to find cancer clinical trials. For specific topics being studied for prostate cancer, learn more in the Current Research section. Side Effects
Cancer and its treatment can cause a variety of side effects. However, doctors have made major strides in recent years in reducing pain, nausea and vomiting, and other physical side effects of cancer treatments. Many treatments used today are less intensive but as effective as treatments used in the past. Doctors also have many ways to provide relief to patients when such side effects do occur. Fear of treatment side effects is common after a diagnosis of cancer, but it may be helpful to know that preventing and controlling side effects is a major focus of your health care team. Before treatment begins, talk with your doctor about possible side effects of the specific treatments you will be receiving. The specific side effects that can occur depend on a variety of factors, including the type of cancer, its location, the individual treatment plan (including the length and dosage of treatment), and the person’s overall health. Ask your doctor which side effects are most likely to happen (and which are not), when side effects are likely to occur, and how they will be addressed by the health care team if they do happen. Also, be sure to communicate with the doctor about side effects you experience during and after treatment. Learn more about the most common side effects of cancer and different treatments, along with ways to prevent or control them. In addition to physical side effects, there may be psychosocial (emotional and social) effects as well. Learn more about the importance of addressing such needs, including concerns about managing the cost of your medical care. Learn more about late effects or long-term side effects by reading the After Treatment section or talking with your doctor. After Treatment
After treatment for prostate cancer ends, talk with your doctor about developing a follow-up care plan. This plan may include regular physical examinations and/or medical tests to monitor your recovery for the coming months and years. Men recovering from prostate cancer are encouraged to follow established guidelines for good health, such as maintaining a healthy weight, not smoking, eating a balanced diet, and having recommended cancer screening tests. Talk with your doctor to develop a plan that is best for your needs. Moderate physical activity can help rebuild your strength and energy level. Your doctor can help you create an appropriate exercise plan based upon your needs, physical abilities, and fitness level. Learn more about healthy living after cancer. For information on coping with cancer, visit the Coping section of Cancer.Net, which contains important topics for men with prostate cancer, such as self-image and cancer, dealing with cancer recurrence, fertility and cancer treatment, and talking with your spouse or partner. Find out more about common terms used after cancer treatment is complete. Current Research
Research for prostate cancer is ongoing. The following advances may still be under investigation in Clinical Trials and may not be approved or available at this time. Always discuss all diagnostic and treatment options with your doctor. Identifying causes of prostate cancer. Researchers continue to explore the link between nutrition and lifestyle factors in the development of prostate cancer. PSA test improvements. Researchers are developing a better PSA test, either a more specific and precise test or another test altogether. With improved testing, larger numbers of healthy men could be screened for prostate cancer, so more prostate cancers can be found and treated early. Improved surgical techniques. Better techniques for nerve-sparing surgery can improve the likelihood that men who need radical prostatectomy retain their urinary continence and sexual potency after surgery. Shorter courses of radiation therapy. With better, more precise external-beam radiation therapy, researchers are exploring much shorter and convenient treatment schedules. Instead of 40 treatments, researchers are evaluating 28, 12, or only five treatments. High-intensity focused ultrasound (HIFU). This procedure, which is still investigational in the United States, uses transrectal ultrasound to heat and destroy cancer cells. Tests that evaluate the success of treatment. These tests can help doctors know if chemotherapy is working.
Questions to Ask the Doctor
Regular communication with your doctor is important in making informed decisions about your health care. Consider asking the following questions of your doctor: Before diagnosis/prevention and screening
After a diagnosis of prostate cancer
Patient Information Resources
In addition to Cancer.Net, there are other sources of information about this type of cancer available online. Cancer.Net maintains a list of national, not-for-profit organizations that may be helpful in finding additional information, services, and support. As always, be sure to talk with your doctor about questions you may have about information you find about this disease. View organizations that offer information on this specific type of cancer. |
