Somatic sex chromatin of blood neutrophyls and the metabolism of glucocorticoid hormones were studied in 20 female patients with the intact ovarian function suffering breast cancer of stage III and in 20 healthy females of the same age. A reliable decrease was found in the number of type A and B processes compared with the control group. The same patients showed the increased nonconjugated 17-OCS in the urine, a decrease in the reduced forms of THF and THE hormones and rising of the cortisol and cortisone level. Breast cancer patients show a higher level of biologically active hormones (cortisol and cortisone), which are likely to influence the amount of somatic sex chromatin under this affection.

The necessity is substantiated to discriminate between the two notions: the oncogenic potency of cell genome and the conditions which either favour or prevent its realization. Both epigenetic alterations and mutations may cause neoplastic transformation of the cell but the expression of the tumor phenotype, composed of normal structural and functional elements, occurs exclusively at the epigenetic level. An impaired selectivity of nucleus-to-cytoplasm transport of mRNAs presumably is involved in this process.

The paper presents data from the literature and the author's own materials on the correlation between the extent of activity of reparation processes and the development of cell malignization. A review cites the results of investigations on the molecular mechanisms in some hereditary human diseases in which a defect in some stages of the reparation processes has been found (xeroderma, ataxia telangesthesia. Fanconi anemia, Down's syndrome, etc.). These diseases are also characterized by a high rate of neoplasia development. It is emphasized that inhibition of the reparation process is observed only in the first stages of normal cell transformation into a malignant one. A correlation between carcinogenic and mutagenic activity of chemical compounds which is in favour of the mutation hypothesis of the origin of tumours is discussed.

The author has studied the predisposition to gastric cancer in familiar probands of russian nationality suffering cancer of the stomach. An analysis of the gastric-cancer incidence among the groups of individuals of different degree of kinship of male and female probands indicates their various predisposition only to cancer of the stomach. Most frequently the affection was noted in the blood relations of female probands (mothers, sisters, and daughters). In this group familial gastric cancer was 5.2 times as frequent as the expected value. Familial gastric cancer among the male blood relations of these probands was no more frequent than among the whole population of russian nationality. Males and females--the blood relations of male probands were affected by gastric cancer approximately twice as frequently as the control subjects. The investigation conducted has shown that distant relations (2d and 3d degree of kinship) of all probands were affected by this kind of cancer at the average population level. Also, all kin groups did not show any high risk for other cancer forms.