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.