Improved overall survival with adjuvant radiotherapy for high-intermediate and high risk Stage I endometrial cancer Journal Article

Authors: Harkenrider, M. M.; Adams, W; Block, A. M.; Kliethermes, S; Small, W., Jr; Grover, S.
Article Title: Improved overall survival with adjuvant radiotherapy for high-intermediate and high risk Stage I endometrial cancer
Abstract: BACKGROUND/PURPOSE: To perform a large analysis of Stage I endometrioid-type endometrial cancer patients to determine the impact of adjuvant radiotherapy (ART) on survival. MATERIAL/METHODS: 132,976 FIGO Stage I endometrioid-type endometrial cancer patients treated surgically were identified within the National Cancer Database (NCDB) comprising Commission on Cancer facilities in the United States. Patients were categorized as observation (OBS) or ART (vaginal brachytherapy, external beam radiotherapy, or both). Univariable generalized linear mixed effects models were used to estimate the odds of receiving ART, and a multivariable frailty survival model was used to estimate the instantaneous hazard of death for those receiving OBS versus ART. Due to the presence of a significant interaction, these estimates were stratified by PORTEC-based low, low-intermediate, high-intermediate, and high risk groups. RESULTS: 104,645 (79%) underwent OBS while 28,331 (21%) received ART. Of those receiving ART, 12,913 (46%) received VBT alone, 12,857 (45%) received EBRT alone, and 2561 (9%) received EBRT+VBT. On univariable analysis, increasing stage/myometrial invasion, higher grade, older age, presence of lymphovascular space invasion, and larger tumor size predicted poorer survival (all p0.01). On multivariable analysis, patients at high-intermediate risk and high risk experienced improved survival with ART with a hazard ratio of 0.796 (95% CI: 0.731-0.867; p0.001) and 0.783 (95% CI: 0.693-0.885; p0.001), respectively. There was no survival benefit for ART among patients at low or low-intermediate risk. CONCLUSIONS: In Stage I high-intermediate and high risk endometrioid-type endometrial cancer patients, ART significantly improves overall survival.
Keywords: Radiation Oncology; endometrial cancer; Vaginal brachytherapy; Adjuvant radiotherapy; External beam radiation therapy; Stage I
Journal Title: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
Volume: 122
Issue: 3
ISSN: 1879-0887; 0167-8140
Publisher: Elsevier Inc  
Journal Place: Ireland
Date Published: 2017
Start Page: 452
End Page: 457
Language: eng
Notes: LR: 20170311; CI: Copyright (c) 2016; JID: 8407192; OTO: NOTNLM; 2016/08/12 [received]; 2016/11/27 [revised]; 2016/12/01 [accepted]; ppublish