Analysis Indicates That Tubal Ligation Is Associated With Lower Endometrial Cancer Stage at Diagnosis and Improved Survival
In an analysis from the NRG Oncology/Gynecologic Oncology Group 210 trial reported in the Journal of the National Cancer Institute, Felix et al found that tubal ligation, which should impede transtubal passage of cells, was associated with lower stage of endometrial cancer at presentation and improved overall survival.
Study Details
The trial included 6,124 women with endometrial carcinoma treated between September 2003 and December 2011 at 62 U.S. sites. The current analysis included 4,489 eligible patients who completed a risk factor questionnaire that included tubal ligation history. Of these, 1,238 had undergone tubal ligation.
Stage
Compared with stage I, patients with tubal ligation vs no tubal ligation were less likely to be diagnosed at stage III (odds ratio [OR] = 0.63, 95% confidence interval [CI] = 0.52–0.78) or stage IV (OR = 0.14, 95% CI = 0.08–0.24) overall. Among individual tumor subtypes, ORs for diagnosis at stage III ranged from 0.47 to 0.89 and were significant for low-grade and high-grade endometrioid tumors and carcinosarcomas; ORs for diagnosis at stage IV ranged from 0.11 to 0.31 and were significant for high-grade endometrioid tumors, serous carcinomas, carcinosarcomas, and clear cell tumors (OR was not evaluable for low-grade endometrioid tumors). Tubal ligation was also inversely related to peritoneal metastasis overall (OR = 0.39, 95% CI = 0.22–0.68) and among serous carcinomas (OR = 0.28, 95% CI = 0.11–0.68).
Survival
In multivariate analysis not including stage, tubal ligation was associated with significantly reduced risk for endometrial carcinoma–specific mortality overall (HR = 0.74, 95% CI = 0.61–0.91) and among serous and clear cell subtypes. With adjustment for stage, the difference was no longer significant overall (HR = 0.99, 95% CI = 0.80–1.22), with a significant difference remaining in the clear cell subtype. Similarly, tubal ligation was associated with significantly better overall survival in multivariate analysis not including stage (HR = 0.77, 95% CI = 0.65–0.91) but not after adjustment for stage (HR = 0.95, 95% CI = 0.80–1.13).
The investigators concluded: “[Tubal ligation] is associated with lower stage and mortality among women with aggressive endometrial carcinomas, suggesting transtubal spread is clinically important. Future studies should evaluate whether detection of intraluminal tumor cells is prognostically relevant.”
Ashley S. Felix, PhD, of the National Cancer Institute, is the corresponding author for the Journal of the National Cancer Institute article.
The study was supported by the National Cancer Institute, Gynecologic Oncology Group Statistical and DataCenter, and NRG Oncology.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
