Salpingectomy for ectopic pregnancy reduces ovarian cancer risk-a nation-wide study.

Recent studies propose fallopian tubes as the tissue origin for many ovarian epithelial cancers. To further support this paradigm, we assessed whether salpingectomy for treating ectopic pregnancy had a protective effect using the Taiwan Longitudinal National-Health-Research Database. We identified 316,882 women with surgical treatment for ectopic pregnancy and 3,168,820 age- and index-date-matched controls from 2000-2016. In a nested cohort, 91.5% of cases underwent unilateral salpingectomy, suggesting that most surgically managed patients have salpingectomy. Over a follow-up period of 17 years, the ovarian carcinoma incidence was 0.0069 (95%CI : 0.0060-0.0079) and 0.0089 (95%CI : 0.0086-0.0092) in the ectopic pregnancy and the control groups, respectively (p < .001). After adjusting the events to per 100-person years, the hazard ratio in the ectopic pregnancy group was 0.70 (95%CI : 0.61-0.80). The risk reduction occurred only in epithelial ovarian cancer (HR : 0.73, CI : 0.63-0.86) and not in non-epithelial subtypes. These findings show a decrease in ovarian carcinoma incidence following salpingectomy for treating ectopic pregnancy.