Tubal ligation, hysterectomy and ovarian cancer: A meta-analysis

Abstract

Purpose: The purpose of this meta-analysis was to determine the strength of the association between gynecologic surgeries, tubal ligation and hysterectomy, and ovarian cancer.

Methods: We searched the PubMed, Web of Science, and Embase databases for all English-language articles dated between 1969 through March 2011 using the keywords "ovarian cancer" and "tubal ligation" or "tubal sterilization" or "hysterectomy." We identified 30 studies on tubal ligation and 24 studies on hysterectomy that provided relative risks for ovarian cancer and a p-value or 95% confidence interval (CI) to include in the meta-analysis. Summary RRs and 95% CIs were calculated using a random-effects model.

Results: The summary RR for women with vs. without tubal ligation was 0.70 (95%CI: 0.64, 0.75). Similarly, the summary RR for women with vs. without hysterectomy was 0.74 (95%CI: 0.65, 0.84). Simple hysterectomy and hysterectomy with unilateral oophorectomy were associated with a similar decrease in risk (summery RR = 0.62, 95%CI: 0.49-0.79 and 0.60, 95%CI: 0.47-0.78, respectively). In secondary analyses, the association between tubal ligation and ovarian cancer risk was stronger for endometrioid tumors (summary RR = 0.45, 95%CI: 0.33, 0.61) compared to serous tumors.

Conclusion: Observational epidemiologic evidence strongly supports that tubal ligation and hysterectomy are associated with a decrease in the risk of ovarian cancer, by approximately 26-30%. Additional research is needed to determine whether the association between tubal ligation and hysterectomy on ovarian cancer risk differs by individual, surgical, and tumor characteristics.

Figure 1

Selection of studies on tubal ligation and hysterectomy with risk of ovarian cancer.

Figure 2

Forest plot for 30 studies of the association between tubal ligation and ovarian cancer risk. Forest plot summarizing individual effect estimates from 30 studies [9-37] contributing to summary effect estimates describing the association between tubal ligation and ovarian cancer risk. Black boxes mark the effect estimate for individual studies and the size of the black boxes represent the weight of individual studies in the summary estimate; horizontal gray lines demonstrate the width of the 95%CIs associated with each individual study; the black diamonds represent summary effect estimates; stars indicate pooled studies.

Figure 3

Forest plot for 24 studies of the association between hysterectomy and ovarian cancer risk. Forest plot summarizing individual effect estimates from 24 studies [9,10,12,13,15,16,23,26,29,31,32,38-47] contributing to summary effect estimates describing the association between hysterectomy and ovarian cancer risk. Black boxes mark the effect estimate for individual studies and the size of the black boxes represent the weight of individual studies in the summary estimate; horizontal gray lines demonstrate the width of the 95% CIs associated with each individual study; the black diamonds represent summary effect; stars indicate pooled studies. HUO=hysterectomy with unilateral oophorectomy, SH=simple hysterectomy, UH=unknown type of hysterectomy.