Hereditary aspects of prostate cancer.CMAJ 1995; 153(7):895-900CMAJ
To review current literature on the hereditary aspects of prostate cancer and to evaluate the importance of family history in history taking and screening for prostate cancer.
MEDLINE was searched for articles in English or French published between Jan. 1, 1956, and Oct. 31, 1994, with the use of MeSH headings "prostatic neoplasms," "genetics" and "chromosomes." Additional references were selected from the bibliographies of articles found during the search.
Case-control studies involving the incidence of prostate cancer and relative risk (RR) of such cancer in the families of men with this disease, compared with a control group, were included. Only studies in which prostate cancer was diagnosed on the basis of histologic tests were included. Animal investigations were excluded.
Ten case-control studies were evaluated critically in terms of design, case and control groups, the size of the samples and statistical results. The incidence of prostate cancer in the families of cases, compared with that in the families of controls, and differences in RR were reviewed.
The lifetime risk of prostate cancer is 9.5% and of death from prostate cancer is 2.9% for a man 50 years of age. For first-degree male relatives of men with prostate cancer, the calculated RR ranges from 1.7 to 8.73. "Hereditary" prostate cancer is a term applied to a specific subset of patients with prostate cancer. This form of prostate cancer is transmitted by a rare, autosomal, dominant allele with high penetrance; it accounts for an estimated 43% of early-onset disease (affecting men less than 55 years of age) but only 9% of all prostate cancer in men up to 85 years of age. A greater number of affected family members and early onset among family members are the most significant predictors of risk.
Recent confirmation of the familial clustering and Mendelian inheritance patterns of some prostate cancer has important implications. It increases the potential for directed research into the causes of prostate cancer and for refinements in the current screening practices to detect this common disease. Manoeuvres to detect prostate cancer should be started earlier among men with one or more first-degree relatives with the disease than among other men.