PROSTATE CANCER

Epidemiology
After heart disease, cancer is the second most common cause of death in the United States. Prostate cancer is the most common cancer in men and accounts for 43% of newly diagnosed cancers. After lung cancer, it is the second most common cause of death from cancer, accounting for 14% of cases. It is estimated that in 1997, 334,500 new cases of prostate cancer in the United States will be found, and that in the same year, 41,800 people will die from the disease. Since the mid-1980’s, the incidence of prostate cancer has been rising sharply, mostly because of the use of prostate specific antigen (PSA). Although it is premature to be certain, it now appears that the incidence rate is leveling off. More importantly, the mortality rate may be beginning to decline for the first time, possibly due to the cancers being detected early when PSA first came in to use ten years ago.

Risk Factors
A family history of prostate cancer is the strongest predictor, although most prostate cancers in men occur in those without a family history. Familiar prostate cancer appears to be linked to a gene on Chromosome #1.

African American men have a higher risk than any other group in the United States. High fat diet may be linked to prostate cancer as well and may explain the fact that families immigrating to the United States from other countries where there is a low incidence of prostate cancer, may soon develop the same incidence as other families in the United States, after one or two generations.

Screening
Although the widespread use of screening for prostate cancer in otherwise healthy men with PSA and digital rectal exam is controversial because of cost and the undetermined risk/benefit ratio, there is no doubt that prostate cancer is being diagnosed earlier and more often.

Currently, the American Cancer Society and the American Urological Association recommend a rectal exam and a PSA blood test on an annual basis for men over 50 years. For African American men or man with a family history the recommended age is 40 years old.

Diagnosis
An abnormal PSA blood test or rectal exam is suspicious for cancer and usually warrants further testing. Although the PSA may be elevated for other reasons such as an enlarged prostate, prostatitis, or infection, cancer must be ruled out. The diagnosis of prostate cancer is usually done with the use of a transrectal ultrasound probe and biopsy done as an office procedure. The ultrasound and biopsy of the prostate is a short office procedure but requires preparation with an enema and oral antibiotics. The patient may experience some bleeding in the urine, stool, and/or semen, but the infection rate is low.

Staging
Once diagnosis of prostate cancer has been made, the extent or stage of the cancer has to be determined. Usually, the higher the PSA blood test, the higher the stage is likely to be, although this is not always the case.

A bone scan is the best way to determine if a cancer has spread to the bones. A CT and scan of the pelvis can be used to determine if the cancer has spread to the lymph nodes, although this test is not very reliable, if spread of cancer to the lymph nodes is only minimal. The best way to determining lymph node status is to surgically remove the lymph nodes either during surgery to remove the prostate (prostatectomy) or as a separate procedure.

Recently, MRI (Magnetic Resonance Imaging), using an endorectal coil is showing promise to determine if a tumor has spread outside the capsule of the prostate or into the seminal vesicles. Further studies are needed to determine if the MRI is truly reliable.

Therapy Options
Treatment for prostate cancer depends on the stage of the tumor and the health of the patient or expected life expectancy.

Observation - Observation or watchful waiting is an accepted choice, especially if the tumor that is found is small and if the patient is either in poor health or has other medical problems. This is usually not a good option if a patient is relatively young and healthy.

Prostatectomy - A total or radical prostatectomy includes a surgical removal of the prostate gland and seminal vesicles. This is usually performed through a retropubic approach. This offers an excellent chance of cure it the tumor is truly confined to the prostate.

The side effects include: urinary incontinence (leakage of urine) and impotency. Incontinence is unusual, since surgical techniques have improved and impotency can be prevented in select cases if a nerve sparing surgery is performed. However, many treatment options are now available to treat both impotency and urinary incontinence.

Radiation therapy - Radiation therapy can also be used to treat prostate cancer when the tumor is either confined or has spread locally outside the prostate. This does not involve the removal of the prostate, but the tumor cells are killed by radiation therapy. The complications include impotency and urinary incontinence. Bowel or rectal problems are unusual.

Radiation therapy can be given in two ways. 1) External beam radiation includes daily short doses of radiation for four to six weeks, delivered from outside the body. 2) Brachytherapy: Involves radiation therapy given by radioactive seeds implanted into the prostate. This is done accurately with the used of prostate ultrasound and this technique can deliver more radiation to the prostate gland with less complications to the adjacent tissue such as bladder or rectum. Occasionally, brief periods of external beam radiation therapy and/or hormone therapy are given prior to seed implantation. This additional therapy and/or hormone therapy is indicated if local spread outside the prostate is suspected or if the prostate gland is too large.

Hormone therapy - Hormone therapy can be either administered by monthly injections or by the surgical removal of the testes. This eliminates the male sex hormone, testosterone, which starves the cancer and kills tumor cells. This can cure some patients, but sometimes the cancer eventually grows, despite the lack of testosterone.

This therapy is usually reserved for patients with more advanced tumors such as lymph node involvement or bone metastases.

Hormone therapy can also be used for some patients only temporarily, prior to either prostatectomy or radiation therapy, to possibly improve local treatment. Although this therapy has not been proven, the results seem promising.

The complications of hormone therapy may include male menopause. Some patients experience lack of sexual desire and ability, mood swings, hot flashes, weight gain, and slight breast enlargement or tenderness.