The prostate is a gland in a man’s reproductive system. It makes and stores seminal fluid, a milky fluid that nourishes sperm. This fluid is released to form part of semen. The prostate is about the size of a walnut. It is located below the bladder and in front of the rectum. It surrounds the upper part of the urethra, the tube that empties urine from the bladder. The causes of prostate cancer are not well understood. Studies have found that the following risk factors are associated with prostate cancer:
- Age. In the United States, prostate cancer is found mainly in men over age 55. The average age of patients at the time of diagnosis is 70. Family history of prostate cancer. A man’s risk for developing prostate cancer is higher if his father or brother has had the disease. Race. This disease is much more common in African American men than in white men. It is less common in Asian and American Indian men.
- Diet and dietary factors. Some evidence suggests that a diet high in animal fat may increase the risk of prostate cancer and a diet high in fruits and vegetables may decrease the risk.
A man who has any of the risk factors may want to ask a doctor whether to begin screening for prostate cancer (even though he does not have any symptoms), what tests to have, and how often to have them. The doctor may suggest either of the tests described below.
- Digital rectal exam–the doctor inserts a lubricated, gloved finger into the rectum and feels the prostate through the rectal wall to check for hard or lumpy areas.
- Blood test for prostate-specific antigen (PSA)–a lab measures the levels of PSA in a blood sample. The level of PSA may rise in men who have prostate cancer, BPH, or infection in the prostate.
Early prostate cancer often does not cause symptoms. But prostate cancer can cause any of these problems:
- A need to urinate frequently, especially at night; Difficulty starting urination or holding back urine; Inability to urinate; Weak or interrupted flow of urine; Painful or burning urination; Difficulty in having an erection; Painful ejaculation; Blood in urine or semen; or
- Frequent pain or stiffness in the lower back, hips, or upper thighs.
If a man has symptoms or test results that suggest prostate cancer, the doctor may order exams to learn more about the cause of the symptoms. These may include:
- Transrectal ultrasonography–sound waves that cannot be heard by humans (ultrasound) are sent out by a probe inserted into the rectum. The waves bounce off the prostate, and a computer uses the echoes to create a picture called a sonogram. Intravenous pyelogram–a series of x-rays of the organs of the urinary tract. Cystoscopy–a procedure in which a doctor looks into the urethra and bladder through a thin, lighted tube.
- Biopsy–If test results suggest that cancer may be present, the man will need to have a biopsy. During a biopsy, the doctor removes tissue samples from the prostate, usually with a needle. A pathologist looks at the tissue under a microscope to check for cancer cells.
If cancer is found in the prostate, the doctor needs to know the stage, or extent, of the disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, what parts of the body are affected. These are the main features of each stage:
- Stage I or Stage A–The cancer cannot be felt during a rectal exam. It may be found by accident when surgery is done for another reason, usually for BPH. There is no evidence that the cancer has spread outside the prostate. Stage II or Stage B–The tumor involves more tissue within the prostate, it can be felt during a rectal exam, or it is found with a biopsy that is done because of a high PSA level. There is no evidence that the cancer has spread outside the prostate. Stage III or Stage C–The cancer has spread outside the prostate to nearby tissues.
- Stage IV or Stage D–The cancer has spread to lymph nodes or to other parts of the body.
Decisions about prostate cancer treatment involve many factors. Before making a decision, a man may want to get a second opinion by asking another doctor to review the diagnosis and treatment options. A short delay will not reduce the chance that treatment will be successful. Treatment for prostate cancer depends on the stage of the disease and the grade of the tumor (which indicates how abnormal the cells look, and how likely they are to grow or spread). Other important factors in planning treatment are the man’s age and general health and his feelings about the treatments and their possible side effects. Treatment for prostate cancer may involve watchful waiting, surgery, radiation therapy, or hormonal therapy. Some patients receive a combination of therapies. Watchful waiting may be suggested for some men who have prostate cancer that is found at an early stage and appears to be slow growing. Also, watchful waiting may be advised for older men or men with other serious medical problems. For these men, the risks and possible side effects of surgery, radiation therapy, or hormonal therapy may outweigh the possible benefits. Surgery is a common treatment for early stage prostate cancer. The doctor may remove all of the prostate (a type of surgery called radical prostatectomy) or only part of it. In some cases, the doctor can use a new technique known as nerve-sparing surgery. This type of surgery may save the nerves that control erection. However, men with large tumors or tumors that are very close to the nerves may not be able to have this surgery. Radiation therapy (also called radiotherapy) uses high-energy x-rays to kill cancer cells. Like surgery, radiation therapy is local therapy; it can affect cancer cells only in the treated area. In early stage prostate cancer, radiation can be used instead of surgery, or it may be used after surgery to destroy any cancer cells that may remain in the area. Radiation may be directed at the body by a machine (external radiation), or it may come from tiny radioactive seeds placed inside or near the tumor (internal or implant radiation, or brachytherapy). Men who receive radioactive seeds alone usually have small tumors. Some men with prostate cancer receive both kinds of radiation therapy. There are several forms of hormonal therapy. :Prostate cancer that has spread to other parts of the body usually can be controlled with hormonal therapy for a period of time, often several years. Eventually, however, most prostate cancers are able to grow with very little or no male hormones. When this happens, hormonal therapy is no longer effective, and the doctor may suggest other forms of treatment that are under study. It is hard to limit the effects of treatment so that only cancer cells are removed or destroyed. Because healthy cells and tissues may be damaged, treatment often causes unwanted side effects. The side effects of cancer treatment depend mainly on the type and extent of the treatment.
- Watchful Waiting. Although men who choose watchful waiting avoid the side effects of surgery and radiation, there can be some negative aspects to this choice. Watchful waiting may reduce the chance of controlling the disease before it spreads. Also, older men should keep in mind that it may be harder to manage surgery and radiation therapy as they age. Surgery. Patients are often uncomfortable for the first few days after surgery. Their pain usually can be controlled with medicine, and patients should discuss pain relief with the doctor or nurse. The patient will wear a catheter (a tube inserted into the urethra) to drain urine for 10 days to 3 weeks. It is also common for patients to feel extremely tired or weak for a while. Surgery to remove the prostate may cause long-term problems, including rectal injury or urinary incontinence. Some men may have permanent impotence. Nerve-sparing surgery is an attempt to avoid the problem of impotence. Radiation Therapy. Radiation therapy may cause patients to become extremely tired, especially in the later weeks of treatment. Some men may have diarrhea or frequent and uncomfortable urination. When men with prostate cancer receive external radiation therapy, it is common for the skin in the treated area to become red, dry, and tender. External radiation therapy can also cause hair loss in the treated area. The loss may be temporary or permanent, depending on the dose of radiation. Both types of radiation therapy may cause impotence in some men, but internal radiation therapy is not as likely as external radiation therapy to damage the nerves that control erection. However, internal radiation therapy may cause temporary incontinence. Long-term side effects from internal radiation therapy are uncommon.
- Hormonal Therapy The side effects of hormonal therapy depend largely on the type of treatment. Men who receive total androgen blockade may experience more side effects than men who receive a single method of hormonal therapy. Any method of hormonal therapy that lowers androgen levels can contribute to weakening of the bones in older men.
During and after treatment, the doctor will continue to follow the patient. The doctor will examine the man regularly to be sure that the disease has not returned or progressed, and will decide what other medical care may be needed. Followup exams may include x-rays, scans, and lab tests, such as the PSA blood test.
Background information provided by: National Cancer Institute, National Institutes of Health, Bethesda, MD 20892