STUDIES OF GENETIC-FACTORS IN PROSTATE-CANCER IN A TWIN POPULATION

It has been suggested that positive family history constitutes a risk factor for the development of prostate cancer. Familial clustering of prostate cancer might suggest that genetic factors are of importance i n the etiology of this disease. To elucidate further the relative impo rtance of genetic factors, we studied prostate cancer among an unselec ted Swedish twin population. Information from the Swedish Twin Registr y and the Swedish Cancer Registry was used. In 4,840 male twin pairs 4 58 prostate cancers were identified between 1959 and 1989. Among these 16 monozygotic and 6 dizygotic twin pairs were concordant for prostat e cancer. Proband concordance rates of 0.192 and 0.043, and a correlat ion of liability of 0.40 and -0.05 were found for monozygotic and dizy gotic pairs, respectively. These differences in proband concordance ra tes and correlations of liability for monozygotic pairs compared to di zygotic pairs are pronounced. The results indicate that genetic factor s might be of importance for the development of prostate cancer. The r esults of this study indicate the need for further investigations of g enetic factors in prostate cancer, including large scale epidemiologic al studies and investigations of molecular genetics of risk families.