PROSTATE CANCER

DEFINITION

Prostate cancer is a disease in which the cells of the prostate become abnormal. They start to grow uncontrollably, forming tumors. A tumor is a mass or lump of tissue made of abnormal cells. Tumors may be malignant or benign. A malignant tumor can spread to other parts of the body. Malignant tumors are cancerous. Benign tumors cannot spread to other parts of the body.

DESCRIPTION

The prostate is one of the major male sex glands. It is about the size of a walnut and lies just behind the urinary bladder. Together with the testicles and seminal vesicles, the prostate produces the fluid that makes up semen.

Prostate cancer is the most common form of cancer among men in the United States. It is the second-leading cause of cancer deaths. According to the American Cancer Society there were approximately 179,300 new cases of prostate cancer diagnosed in the United States in 1999. About thirty-seven thousand American men died of the disease in 1999.

Prostate cancer affects black men twice as often as it does white men. The mortality rate among blacks is also twice as great. African American men have the highest rate of prostate cancer in the world.

As prostate cancer develops, it may metastasize. Metastasis is the process by which cancer cells travel from one part of the body to another. The most common sites to which it spreads are the lymph nodes, the lungs, and various bones in the hip region.

CAUSES

The cause of prostate cancer is not known. It is found primarily in men over the age of fifty-five. The average age of diagnosis is seventy-two. As men grow older, their likelihood of getting prostate cancer increases. For men under the age of forty, the chance of getting prostate cancer is about 1 in 100,000. For men seventy to seventy-four years old, the chance rises to 1,326 in 100,000.

Certain factors increase a man's risk for prostate cancer. These factors include:

• A family history of prostate cancer
• A high-fat diet
• Work in the electroplating, welding, and rubber industries
• High blood testosterone (a male sex hormone) levels

SYMPTOMS

In many cases prostate cancer has no symptoms in its early stages. The disease is usually discovered during a routine physical examination. As the

Former U.S. Senator Bob Dole, who was diagnosed with prostate cancer in 1990, helps promote prostate cancer awareness at the National Men's Health and Fitness Conference in Philadelphia, PA in 1999. (Reproduced by permission of

AP/Wide World Photos

)

disease develops, certain symptoms are more likely to appear. These symptoms include:

• Weak or interrupted flow of urine
• Frequent urination, especially at night
• Difficulty in starting to urinate
• Inability to urinate
• Pain or burning sensation during urination
• Blood in the urine
• Continuous pain in the lower back, hips, or thighs
• Painful ejaculation

DIAGNOSIS

The first step in diagnosing prostate cancer is usually a digital rectal examination. In a digital rectal examination, a doctor places a gloved, lubricated finger into the patient's rectum. The doctor feels for lumps in the prostate.

If the doctor detects a lump, additional tests may be necessary. The first test may be a blood test. The purpose of a blood test is to search for a particular chemical associated with prostate cancer. This chemical is called prostate-specific antigen (PSA). PSA occurs naturally in the blood, but it occurs in much higher amounts if prostate cancer is present.

A second test that may be used is a transrectal (across the rectum) ultrasound. In this test, sound waves are bounced off the prostate gland. The reflected waves form a picture of the prostate. The picture shows the presence of any tumors.

A prostate biopsy may also be necessary. A biopsy is a procedure in which a small sample of tissue is removed. The sample is then studied under the microscope. Cancer cells can be detected under the microscope because of their distinctive appearance.

Other tests may be conducted to see if the cancer has begun to spread. For example, a chest X ray will show if cancer has spread to the lungs. A bone scan may be used to check whether the cancer has spread to the bone.

TREATMENT

A number of treatments are available for prostate cancer. The treatment chosen depends on the patient's age and general health, the stage of the tumor, the presence of other illnesses, and other factors.

The two most common forms of treatment for early prostate cancer are surgery and radiation. Surgery involves the removal of the prostate gland. In addition, a sample of the lymph nodes near the prostate is removed. This sample is then tested to see whether the cancer has spread.

Removal of the prostate also involves removal of the seminal vesicles that lie next to it. The seminal vesicles are the organs that make semen. Since they are usually removed along with the prostate, the patient usually becomes sterile as a result of the operation.

Radiation involves the use of high-energy rays to kill cancer cells. In most cases, the radiation comes from radioactive materials. Radioactive materials are substances that give off high-energy radiation, similar to X rays. The radiation can be given either externally or internally. If it is given externally, the radioactive source is placed above the patient's body in the area of the cancer. Radiation from the source penetrates the body and destroys cancer cells. Radiation can also be given internally by implanting the source in the patient's body.

For more advanced cases of prostate cancer, hormone therapy may be necessary. Prostate cells need the male hormone testosterone to grow. One way to stop the growth of prostate cells, then, is to reduce the amount of testosterone in the body. One way to do that is to surgically remove the patient's testicles. The testicles are the organ that produces testosterone. Another way to achieve the same goal is to give the patient a medication that reacts with testosterone. The medication "cancels out" the testosterone produced by the body.

Finally, the patient may be given a female hormone, such as estrogen. The estrogen makes the body stop producing testosterone. This treatment has some undesirable side effects, however. For example, a man may have "hot flashes," have enlarged and tender breasts, and lose sexual desire.

Chemotherapy may be used if the cancer has metastasized (pronounced muh-TASS-tuh-sized). Chemotherapy involves the use of chemicals that kill cancer cells. These chemicals can be given either orally (by mouth) or intravenously (into the bloodstream). The chemicals spread throughout the patient's body and attack cancer cells wherever they occur. Chemotherapy is sometimes used to treat prostate cancer that has recurred after other treatments.

A final form of treatment is no treatment at all. Prostate cancers sometimes develop very slowly. It may take years for them to become a serious threat to the patient's life. That fact is considered in treating older men. In many cases, the man is likely to die of other causes before prostate cancer becomes a serious concern. The approach in such cases is called "watchful waiting." The patient receives regular checkups. If no major change is found, no treatment is offered. If the tumor becomes significantly larger, one of the above forms of treatment is used.

PROGNOSIS

According to the American Cancer Society, the survival rate for all stages of prostate cancer combined increased from 67 percent in the late 1970s to 93 percent in the late 1990s. The main reason for this change is early detection. When tumors are still small, they can be removed successfully in almost all cases.

About 99 percent of all patients diagnosed with prostate cancer now live at least five years. More than 60 percent survive for ten years, and about 50 percent survive for fifteen years after diagnosis.

PREVENTION

There is no way to prevent prostate cancer. However, early detection can dramatically reduce the threat posed by the disease. The American Cancer Society (ACS) recommends that all men over the age of forty have an annual rectal examination. The ACS also recommends an annual PSA test once a year for men over the age of fifty.

A low-fat diet may slow the progress of prostate cancer. The ACS recommends a diet rich in fruits, vegetables, and fiber and low in red meat and saturated fats.

FOR MORE INFORMATION

Books

Bostwick, David G., Gregory T. MacLennan, and Thayne R. Larson. Prostate Cancer: What Every Man—and His Family—Needs to Know. New York: Villard Books, 1999.

Dollinger, Malin, Ernest H. Rosenbaum, and Greg Cable. Everyone's Guide to Cancer Therapy. Kansas City, MO: Somerville House Books, 1994.

Loo, Marcus, H., and Marian Betancourt. The Prostate Cancer Sourcebook : How to Make Informed Treatment Choices. New York: John Wiley & Sons, 1998.

Morra, Marion, and Eve Potts. Choices. New York: Avon Books, 1994.

Oesterling, Joseph A. The ABC's of Prostate Cancer : The Book That Could Save Your Life. Lanham: Madison Books, 1997.

Wallner, Kent. Prostate Cancer: A Non-Surgical Perspective. Seattle: SmartMedicine Press, 1996.

Organizations

American Cancer Society. 1599 Clifton Rd., N.E., Atlanta, GA 30329. (800) 227–2345.

American Urologic Association. 1120 N. Charles St., Baltimore, MD 21201. (410) 223–4310.

Cancer Research Institute. 681 Fifth Ave., New York, NY 10022. (800) 992–2623.

National Cancer Institute. 31 Center Drive, Bethesda, MD 20892–2580. (800) 4–CANCER. http://www.nci.nih.gov.

National Prostate Cancer Coalition. 1300 19th St., NW, Suite 400, Washington, DC 20036. (202) 842–3600.

Web sites

"Ask NOAH About: Prostate Cancer." NOAH: New York Online Access to Health. [Online] http://www.noah.cuny.edu/cancer/nci/cancernet/201229.html (accessed on October 28, 1999).

"Prostate Action Network." http://rattler.cameron.edu/pacnet (accessed on October 28, 1999).

"Prostate Cancer." The Prostate Cancer Resource Center. [Online] http://www3.cancer.org/cancerinfo/main_cont.asp?st=wi&ct=36 (accessed on October 28, 1999).

The Prostate Cancer Info Link. [Online] http://www.comed.com/Prostate/ (accessed on October 28, 1999).