Epidemiologic Characteristics of Prostate Cancer

Both genetic and exogenous factors are probably important in prostate cancer development, but the specific causes remain poorly understood. An increasing body of evidence now suggests that high animal fat or red meat intake appears to increase risk for this cancer. Some studies indicate that high intake of retinol may be deleterious, but β‐carotene may lower risk, although these data are inconsistent. Carotenoids other than β‐carotene are only now being examined in relation to prostate cancer risk. Ongoing epidemiologic studies may help clarify the relation between diet and prostate cancer. Most studies indicate that men who have had a vasectomy have an increased risk for prostate cancer to develop, although whether this association is causal is unknown. Familial factors are important, particularly at younger ages. Overall, about 9% of cases may be attributed directly to a family history of prostate cancer, although this may be as high as 43% among men younger than 55 years. No occupational factor has been confirmed as a risk factor. Some evidence suggests that occupational exposure to cadmium and some aspect of farming may increase risk moderately, but these would account for a small proportion of the total cases. Dietary factors appear to hold the most promise for primary prevention, but the precise factors and mechanisms need to be better understood. Cancer 1995; 75:1766–77.