Case–control study of ovarian cancer in Japan

A case–control study of 80 women with ovarian epithelial carcinoma and 160 individually age‐matched controls were conducted to assess various factors associated with the incidence of ovarian cancer in Hokkaido, Japan. Among the characteristics studied, the following factors were significantly greater in the cases than in the controls: (1) blood group A; (2) never married or married late in life; (3) more frequent surgery for retroflexion of the uterus; (4) less use of contraceptive appliances; and (5) less daily use of cosmetics. It was inferred from these observations that ovarian cancer patients had a genetic predisposition and dysfunctional ovaries. Gonadal dysfunction among ovarian cancer patients presumably explained not only altered personality and behavior patterns, but also facilitated the pituitary gonadotropin activity which has been suggested as increasing the incidence of the disease experimentally.