Prostate cancer--you can't run away.

As a runner, you've signed up for one of the greatest insurance policies of all time. Running protects your health and wellbeing in an enormous number of ways. But it does not seem to help prevent prostate cancer. Observational data from the Physicians' Health Study (a large prospective study of 22,000 men aged 40 to 84), showed no significant association between frequency of exercise vigorous enough to work up a sweat and prostate cancer. Diet and information are your best weapons against the most commonly occurring cancer in American men.

Risk increases with age--approximately 60% of men develop prostate cancer over time, according to autopsy statistics. Overall incidence is less meaningful than age-specific risk. The incidence is only one per 100,000 among men under 40, but climbs to 1,326 per 100,000 for men 70 to 74 years old. Nearly 180,000 American men will be diagnosed this year and 37,000 will die. Age, race, and family history are the strongest risk factors for prostate cancer. African American men are faced with double the risk of white men, while Asian men have the lowest risk, and men with a first-degree relative with prostate cancer have double the risk of those who don't.

Diet plays a large role, and it's a factor you can control. Dietary animal fat increases your risk, while a high intake of vegetables (especially cruciferous vegetables like cabbage and broccoli) improves your odds. New research shows that men with the highest blood levels of vitamin E were five times less likely to develop prostate cancer. The particular type of vitamin E, gammatocopherol, is not the form usually found in supplements. The gamma form comes primarily from vegetable oils, nuts, seeds, and leafy vegetables.

But the single most important factor in protecting your health from prostate cancer is early detection. Early diagnosis, when tumors are confined to the prostate gland, produces a cure rate of 100%. Cure rates decline dramatically if the cancer has spread beyond the prostate gland and even more so if it has metastasized to distant parts of the body.

The development of the PSA test (prostate specific antigen) revolutionized prostate cancer screening. In the past, the only tool doctors had was the digital rectal exam, and 40% of the men who were found to have prostate cancer with that test already had metastatic spread of the disease.

However, whether or not to test is not as simple a choice as it may appear and there is still controversy within the medical ranks. The PSA test measures a protein produced by the prostate gland found normally in very low quantities in the blood stream. Higher levels may indicate a problem that can then be diagnosed by biopsy. PSA can be higher than normal when the prostate gland is enlarged without the presence of cancer. In that case, an elevated PSA test could lead to unnecessary and invasive procedures. And, some prostate cancers grow so slowly and begin late enough in life that they may never be life threatening.

Even though screening recommendations are still a source of controversy, it is generally accepted that white men over 50 should have an annual PSA test; black men and men with a close family history of the disease should have annual screening over 40. You can't run away, but you can certainly head it off at the pass. For more information visit the Cancer Information Network at http://intouch.cancernetwork.com and The American Cancer Society at www.cancer.org.

(International Journal of Epidemiology, 2000, Vol. 29, No. 1, pp. 29-35; Journal of the National Cancer Institute, 2000. Vol. 92, No. 1, pp. 61-68 and No. 24. pp. 2018-2023)