Tubal ligation, hysterectomy, and interactions with parity in the incidence of ovarian cancer. Garth H. Rauscher, Varant A. Kupelian, Faith Davis, Katherine Mallin, Karin Rosenblatt. Division of Epidemiology and Biostatistics, University of Illinois at Chicago, Chicago, IL; Dept. of Community Health, University of Illinois, Champaign, IL. BACKGROUND: Multiple epidemiologic studies suggest that tubal ligation and hysterectomy protect against risk of ovarian cancer. We re-examined the relation for tubal ligation/hysterectomy, and interactions with parity and number of live births, in a population-based, case-control study (1994-98) in Cook County, Illinois. METHODS: Seventy-five percent of patients and 53% of controls that were contacted by the study were interviewed. Overall case response was 43%, due to hospital refusal to allow contact. Among 351 incident ovarian cancer cases and 501 controls, we estimated relative risks (RR) from odds ratios in logistic regression, for surgery history alone and in combination with parity history while controlling for the study matching factors (age and race), talc use, oral contraceptive (OC) use, and history of ovarian cysts. RESULTS: 32% of control women had a history of surgery; 16% were nulliparous, and 23% had at least four live births. Tubal ligation (RR=0.6, 95% CI: 0.4, 0.9) and hysterectomy (RR=0.8, 95% CI: 0.5, 1.3) were associated with a decreased incidence of ovarian cancer. Surgery appeared to dampen increased risk associated with nulliparity. Compared to multiparous (4+) women with a history of surgery, nulliparous women without surgery had a four-fold increased incidence (RR=4.2, 95% CI: 2.3, 7.7), while nulliparous women with a surgery history were not at increased risk (RR=1.6, 95% CI: 0.6, 4.7). CONCLUSIONS: Tubal ligation and hysterectomy were associated with decreased incidence of ovarian cancer, and the mechanism appears to be in part through negation of risk associated with nulliparity. AACR Abstract Number: R1551, 2003 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.