[Clinico-genetic analysis of the incidence of neoplasms]

The authors sum up the results of clinical and genealogic examinations of 2460 patients with most prevalent tumors, i.e. gastric and mammary carcinomas, melanomas. The obtained values of segregation frequencies for these tumors have proved to be lower than the theoretically expected values for monogenic types of inheritance. A genetic and epidemiologic approach, employed in the tumors analysis, has demonstrated the multifactorial nature of these tumors: the contribution of the genetic factors in mammary carcinoma has made up 52%, in gastric carcinoma 22% for male and 41.1% for female subjects, with the X-chromosome-linked genetic components making up 19%. The studies have shown the possibility of genetic heterogeneity of the tumor forms, identically localized. Basing on these data, the authors have plotted 'repeated risk tables' to assess the potentiality of new cases of the disease in the patients' families; such tables may be useful for practical medicogenetic counselling.