Patient compliance for postoperative radiotherapy and survival outcome of women with stage I endometrioid endometrial cancer

Background and Objectives To examine characteristics and survival outcome of women with endometrial cancer who declined postoperative radiotherapy. Methods A retrospective study was conducted to examine surgically-treated grade 1-2 stage IB and grade 3 stage IA-IB endometrioid endometrial cancer in the Surveillance, Epidemiology, and End Results Program between 1983 and 2013 (n = 10 613). Associations of patient declination for guideline-based postoperative radiotherapy and clinico-pathological demographics or survival outcome were examined on multivariable analysis. Results There were 323 (3.0%) women who declined adjuvant radiotherapy. Women who declined postoperative radiotherapy were more likely to be older, White, Western U.S. residents, and register in recent years (all, adjusted-P < 0.05). On multivariable analysis, patient declination for guideline-based postoperative radiotherapy remained an independent prognostic factor for decreased endometrial cancer-specific survival in unstaged grade 1-2 stage IB or staged/unstated grade 3 stage IA-IB diseases (adjusted-hazard ratio 1.84, 95% confidence interval 1.34-2.51, P = 0.001). Association of patient declination for guideline-based postoperative radiotherapy and decreased overall survival remained independent in the entire cohort on multivariable analysis (adjuvant-hazard ratio 1.71, 95% confidence interval 1.44-2.02, P < 0.001). Conclusions Our study suggested that patient compliance to guideline-based postoperative radiotherapy is a prognostic factor for women with stage I endometrioid endometrial cancer.