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 (EC) but the primary preventive effect of the procedure is unclear. In a Swedish nationwide population-based cohort study, we crosslinked registry data for tubal ligation, EC, and death for Swedish women between 1973 and 2010. All women were followed until EC, emigration, hysterectomy for non-cancerous reasons, death, or end of follow-up. Primary outcome was incidence of EC and secondary outcome overall survival. We calculated adjusted incidence rates (IR) per 100,000 person-years and hazard ratios (HR) using Cox regression models. A total of 35,711 cases of EC were identified among 5,385,186 women. The IR of EC among exposed was 17.7 (95% CI 15.7-19.9) versus 29.0 (95% CI 28.7-29.3) among unexposed (per 100,000 women years). Exposed individuals had significantly reduced risk of EC (HR 0.73, 95% CI 0.65-0.83). The mortality rate among women with EC was 72% 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 EC as well as mortality rates in women with EC. 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.

Tubal ligation and endometrial Cancer risk: a global systematic review and meta-analysis

“…Full texts of the remaining 16 articles were studied and 6 articles were excluded (2 studies due to duplication and 4 studies due to irrelevant data). Finally, data of 10 remaining papers [2, 12, 15–17, 22–26] was extracted and entered into the meta-analysis. Results of the Newcastle-Ottawa assessment scale for those 10 studies are presented in Fig.…”

“…According to GLOBOCAN worldwide cancer incidence and mortality report, there are annually 14.1 million new cases and 8.1 million deaths due to cancers [1]. According to that report, endometrial cancer is the most frequent gynecological malignancy and the sixth most frequent malignancy among women in the world [2, 3]. In 2012, 320,000 new cases of endometrial cancer were reported worldwide [1].…”

“…According to 2015 World Health Organization Report, this method was used by 19% of women worldwide [4]. However, its prevalence varies extensively around the world with a prevalence of 22% in United States and lower than 10% in Europe [2]. There are also some reports of dwindling interest in this contraceptive method.…”

“…Several studies have concluded that tubal ligation is associated with the following outcomes: a reduction in risk and mortality of endometrial cancer [2, 12], a less chance of endometrial cancer diagnosis at advanced stages [13], lower positive peritoneal cytology, recurrence rate, and metastatic spread of non-endometrioid endometrial carcinoma [14]. On the contrary, several other studies have indicated that there is no such a link between tubal ligation and risk of endometrial cancer [15–17], pointing to a contradiction in our knowledge about this cancer.…”

“…On the contrary, several other studies have indicated that there is no such a link between tubal ligation and risk of endometrial cancer [15–17], pointing to a contradiction in our knowledge about this cancer. Falconer et al [2] postulated that this contradiction can be attributed to methodological limitations and insufficient sample sizes in published studies. Motivated to solve the contradiction, in this study we systematically reviewed all the previously published studies and performed a meta-analysis to determine the association between tubal ligation and endometrial cancer risk.…”