Association between tubal ligation and endometrial cancer risk: A Swedish population-based cohort study

Abstract

Tubal ligation results in less advanced stages and lower risk of metastatic spread at diagnosis of endometrial cancer but the primary preventive effect of the procedure is unclear. In a Swedish nationwide population-based cohort study we cross-linked registry data for tubal ligation, endometrial cancer and death for Swedish women between 1973 and 2010. All women were followed until endometrial cancer, emigration, hysterectomy for non-cancerous reasons, death, or end of follow up. Primary outcome was incidence of endometrial cancer and secondary outcome overall survival. We calculated adjusted incidence rates (IR) per 100,000 person-years and hazard ratios (HR) using Cox regression models. 35,711 cases of endometrial cancer were identified among 5,385,186 women. The IR of endometrial cancer among exposed was 17.7 (95% CI 15.7-19.9) vs. 29.0 (95% CI 28.7-29.3) among unexposed (per 100,000 women years). Exposed individuals had significantly reduced risk of endometrial cancer (HR 0.73, 95% CI 0.65-0.83). The mortality rate among women with endometrial cancer was 72 percent lower in exposed compared to unexposed (IR 1,441; 95% CI 1,089-1,907 and IR 5,136; 95% CI 5,065-5,209 respectively) which following adjustment corresponded to a HR of 0.71 (95% CI 0.49-1.03). Tubal ligation was associated with lower risk of endometrial cancer, as well as, mortality rates in women with endometrial cancer. Elective tubal ligation may be adopted in future cancer preventive strategies but must be balanced against the irreversibility of the procedure, which preclude further unassisted reproduction. This article is protected by copyright. All rights reserved.

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