RESUMO
Prostatic cancer, which is an age-associated and androgen-dependent cancer, is the most common malignancy in males in the United States. Although the etiologic factors in prostate cancer are not clear, increased male sexual activity on a hormonal basis, a viral-venereal connection, and air pollution have been hypothesized. Genetic factors are suggested by racial variation and by familial incidence of prostate cancer; however, with family studies alone, it is not possible to decide if it is genetically determined or if it is due to a greater than average similarity in environment. For cancer in general, the study of concordance rates among populations of twins has failed to establish a precise role for inheritance, but more detailed study of individual types of tumors in twins may reveal a genetic connection. The following report describes the second recorded monozygotic twin set concordant for prostate cancer.