Ovarian Conservation and Overall Survival in Young Women With Early-Stage Low-Grade Endometrial Cancer.

Abstract

To characterize contributing factors for ovarian conservation during surgical treatment for endometrial cancer and to examine the association of ovarian conservation on survival of young women with early-stage, low-grade tumors. This was a population-based study using the Surveillance, Epidemiology, and End Results program to identify surgically treated stage I type I (grade 1-2 endometrioid histology) endometrial cancer cases diagnosed between 1983 and 2012 (N=86,005). Multivariable models were used to identify independent factors for ovarian conservation. Survival outcomes and cause of death were examined for women aged younger than 50 with stage I type I endometrial cancer who underwent ovarian conservation (1,242 among 12,860 women [9.7%]). On multivariable analysis, age younger than 50 years, grade 1 endometrioid histology, and tumor size 2.0 cm or less were noted to be independent factors for ovarian conservation (all, P<.001). For 9,110 women aged younger than 50 years with stage I grade 1 tumors, cause-specific survival was similar between ovarian conservation and oophorectomy cases (20-year rates 98.9% compared with 97.7%, P=.31), whereas overall survival was significantly higher in ovarian conservation cases than oophorectomy cases (88.8% compared with 82.0%, P=.011). On multivariable analysis, ovarian conservation remained an independent prognostic factor for improved overall survival (adjusted hazard ratio 0.73, 95% confidence interval [CI] 0.54-0.98, P=.036) and was independently associated with a lower cumulative risk of death resulting from cardiovascular disease compared with oophorectomy (20-year rates, 2.3% compared with 3.7%, adjusted hazard ratio 0.40, 95% CI 0.17-0.91, P=.029). Contrary, cause-specific survival (20-year rates 94.6% compared with 96.1%, P=.68) and overall survival (81.0% compared with 80.6%, P=.91) were similar between ovarian conservation and oophorectomy among 3,750 women aged younger than 50 years with stage I grade 2 tumors. Ovarian conservation is performed in less than 10% of young women with stage I type I endometrial cancer. Ovarian conservation is associated with decreased mortality in young women with stage I grade 1 tumors.