A case-control study of risk factors for epithelial ovarian cancer

Ovarian cancer is second prevalent cancer among gynecologic malignancies and the most common type of ovarian cancer is epithelial form (85-90 percent). To detect the risk factors for the epithelial ovarian cancer, a case-control study was conducted in Valieasr hospital in 1988. In this study, 118 cases with epithelial ovarian cancer (according histological records) and 240 controls without any gynecological cancer in gynecologic clinic had been interviewed. For data analysis, T-test, Chi2 test and logistic regression have been used at a =0.05 as level of significance. The mean age in cases was 50±13 and in controls was 49.9±12 years, without significant different. The mean number of pregnancies and parity in cases was less than controls, significantly (P<0.03). The mean months of breast feeding in cases was less than controls (54.9±71.2 versus 82.4±62.7) (P<0.001). The cases had a lower mean age of menarch than controls (P=0.03). 58 percent of cases and 21.3 percent of controls hadn't used any contraception methods (P=0.00001). The mean years of contraception was significantly less in cases versus controls (P<0.001). The odds ratio for epithelial ovarian cancer was 0.24 (95 percent CI: 0.13-0.48) in OCP users, 0.47 (95 percent CI: 0.005-0.43) in TL method, and was 0.41 (95 percent CI: 0.22-0.76) in other contraception methods, relative to women who hadn't used any contraception methods. This study reveals that epithelial ovarian cancer risk increases significantly with earlier menarch, decreasing number of pregnancy, deliveries duration of breast feeding and use of contraception methods. Use of contraception pill and tubal ligation method decreases risk of epithelial ovarian cancer