Is variety really the spice of life? An NCDB analysis of treatment patterns of stage IB grade 3 endometrioid endometrial carcinoma (192)

Abstract

Objectives: No clear consensus exists for the optimal treatment of stage IB grade 3 endometrioid endometrial carcinoma (EC). We sought to describe national treatment patterns over time and examine associations between treatment modality and overall survival (OS). Methods: Using data from the National Cancer Database, we identified 3,964 women with stage IB grade 3 endometrioid EC diagnosed between 2010 and 2016. We used multivariable-adjusted logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations of demographic and tumor characteristics with the type of adjuvant treatment received (surgery only, radiation only [RT], or chemotherapy +/- radiation [chemo +/- RT]). Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% CIs for associations between type of adjuvant therapy and OS in the overall study population and stratified by age (<50, 50-69, >70), and presence of lymphovascular space invasion (LVSI, no vs yes). Results: Approximately one-third received surgery only (31%), 20% received vaginal brachytherapy (VBT) alone, 23% received external beam radiation (EBRT) +/- VBT, 6% chemo only, 11% received chemo + VBT, and 7.8% received chemo + EBRT +/-VBT. Over the study period, the proportion of women undergoing surgery alone decreased from 38% in 2010 to 27% in 2016, while proportions of women receiving chemo +/- RT increased from 17% in 2010 to 28% in 2016. Treatment with chemo +/- RT was associated with improved survival, independent of LVSI (HR: 0.54; 95% CI: 0.45-0.64). When stratifying by both age and LVSI, the benefit of chemo +/- RT was most pronounced for the subgroup of women >70 with LVSI present (HR: 0.51; 95% CI: 0.37-0.71). During the study period, a more recent diagnosis was associated with improved OS (HR 2016 vs 2010: 0.96; 95% CI: 0.71-1.30; HR 2011 vs 2010: 1.30; 95% CI: 1.07-1.59). Conclusions: Wide variation exists in the treatment of stage IB grade 3 EC, uterine-confined cancer with a propensity for distant recurrence. Over the study period, concomitant increases in systemic therapy and radiation with decreases in surgery alone were observed. Use of chemo +/- RT was associated with improved survival. Although additional data are needed to inform optimal treatment recommendations for women with stage IB G3 endometrial cancer, our results suggest that systemic chemotherapy, which has increased over time, may play a role in improving survival. Objectives: No clear consensus exists for the optimal treatment of stage IB grade 3 endometrioid endometrial carcinoma (EC). We sought to describe national treatment patterns over time and examine associations between treatment modality and overall survival (OS). Methods: Using data from the National Cancer Database, we identified 3,964 women with stage IB grade 3 endometrioid EC diagnosed between 2010 and 2016. We used multivariable-adjusted logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations of demographic and tumor characteristics with the type of adjuvant treatment received (surgery only, radiation only [RT], or chemotherapy +/- radiation [chemo +/- RT]). Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% CIs for associations between type of adjuvant therapy and OS in the overall study population and stratified by age (<50, 50-69, >70), and presence of lymphovascular space invasion (LVSI, no vs yes). Results: Approximately one-third received surgery only (31%), 20% received vaginal brachytherapy (VBT) alone, 23% received external beam radiation (EBRT) +/- VBT, 6% chemo only, 11% received chemo + VBT, and 7.8% received chemo + EBRT +/-VBT. Over the study period, the proportion of women undergoing surgery alone decreased from 38% in 2010 to 27% in 2016, while proportions of women receiving chemo +/- RT increased from 17% in 2010 to 28% in 2016. Treatment with chemo +/- RT was associated with improved survival, independent of LVSI (HR: 0.54; 95% CI: 0.45-0.64). When stratifying by both age and LVSI, the benefit of chemo +/- RT was most pronounced for the subgroup of women >70 with LVSI present (HR: 0.51; 95% CI: 0.37-0.71). During the study period, a more recent diagnosis was associated with improved OS (HR 2016 vs 2010: 0.96; 95% CI: 0.71-1.30; HR 2011 vs 2010: 1.30; 95% CI: 1.07-1.59). Conclusions: Wide variation exists in the treatment of stage IB grade 3 EC, uterine-confined cancer with a propensity for distant recurrence. Over the study period, concomitant increases in systemic therapy and radiation with decreases in surgery alone were observed. Use of chemo +/- RT was associated with improved survival. Although additional data are needed to inform optimal treatment recommendations for women with stage IB G3 endometrial cancer, our results suggest that systemic chemotherapy, which has increased over time, may play a role in improving survival.