Vitamins A and E: Further Clues for Prostate Cancer Prevention

Extract

The initiation and progression of prostate cancer seems to involve a complex series of both endogenous and exogenous factors. While the frequency of latent prostate cancer is fairly evenly distributed among populations, the rate of transition from latent to progressive, clinically evident cancer shows considerable variation among populations (1). Migrants from countries with low rates of prostate cancer, moreover, tend to assume the higher rates of their new countries within a fairly short period of time, suggesting that environmental factors may play an important role in promoting clinically detectable cancer.

Known risk factors for prostate cancer include age, family history, and race. After age 50 years, both incidence and mortality rates from prostate cancer increase at a nearly exponential rate, more so than with any other major cancer. Younger age at onset of disease is also associated with a family history of prostate cancer: 18% of the patients who were less than 65 years of age at the onset of the disease have a positive family history compared with only 6% of older patients (2). The risk of developing prostate cancer also increases with the number of affected first-degree relatives and with a lower age of onset for those affected relatives (3). Several studies (3–5) suggest that a rare, highly penetrant dominant allele is responsible for this inherited form of prostate cancer, which may also account for some of the racial differences in disease patterns. Worldwide, African Americans have the highest incidence of clinically evident disease, at rates greater than 13 times those of men in China and Japan where rates are the lowest.