The role of adjuvant chemotherapy in FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma treated with surgery and postoperative radiotherapy

Abstract

Objectives: The optimal treatment of FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma remains unknown. It is unclear if adjuvant chemotherapy (CHT) in addition to adjuvant radiotherapy enhances survival in this subgroup of endometrial cancer patients. The goals of the present study were to perform a National Cancer Database (NCDB) analysis in this cohort of patients to 1) compare overall survival following treatment with a hysterectomy and adjuvant radiotherapy with or without CHT, 2) evaluate CHT utilization in the United States, and 3) investigate which factors are associated with survival in stage IB grade 3 endometrioid adenocarcinoma patients. Methods: Patients diagnosed between 2004 and 2015 with FIGO stage IB grade 3 endometrial endometrioid adenocarcinoma treated with hysterectomy and postoperative radiotherapy with or without adjuvant systemic CHT were identified in the NCDB. Overall survival (OS) was assessed with Kaplan-Meier curves, and differences between groups were compared with the log-rank test. A Cox model was constructed to evaluate survival after controlling for confounders, and logistic regression was used to reveal predictors of CHT use. Results: While the receipt of CHT was associated with a trend toward increased 5-year OS from 68.1% to 74.7% (p=0.059), this association did not reach statistical significance on propensity score weighted (p=0.073) and multivariate analyses (adjusted HR (aHR) 0.86; CI: 0.70-1.06; p=0.15) as shown in the figure. Moreover, there was some evidence of a differential CHT effect in patients who did not undergo a lymphadenectomy (LND; p=0.056); CHT was associated with a trend toward reduced hazard of death in patients with LND (aHR=0.82, CI: 0.66-1.01, p=0.0634) but not in patients who did not undergo LND (aHR=1.70, CI: 0.86-3.35, p=0.1255). Patients who underwent brachytherapy as opposed to external beam radiotherapy, had lymphovascular space invasion (LVSI), were 59 years or younger, were diagnosed in the more recent years of the study and treated in higher facility case volume centers were more likely to: receive adjuvant chemotherapy. No LND (HR 1.51; CI: 1.13-2.03; p=0.0057), positive LVSI (HR 1.71; CI: 1.36-2.16; p 70 (HR 2.61; CI: 2.03-3.36; p Download : Download high-res image (275KB) Download : Download full-size image Conclusions: Adjuvant CHT plus radiotherapy was associated with a non-statistically significant increase in OS in FIGO stage IB grade 3 endometrioid adenocarcinoma patients compared to those treated with adjuvant radiotherapy alone. This potential effect is most apparent in patients who underwent LND.