Guideline-concordant endometrial cancer treatment and survival in the Women's Health Initiative Life and Longevity After Cancer study

In the Women's Health Initiative (WHI) Life and Longevity After Cancer (LILAC) cohort, we examined predictors of guideline-concordant treatment among endometrial cancer (EC) survivors and associations between receipt of guideline-concordant treatment and survival. Receipt of guideline-concordant EC treatment was defined according to year-specific National Comprehensive Cancer Network (NCCN) guidelines. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for predictors of guideline-concordant treatment receipt. We estimated multivariable-adjusted hazard ratios (HRs) and 95% CIs for relationships between guideline-concordant treatment and overall survival using Cox proportional hazards regression. We included 629 women with EC, of whom 83.6% (n = 526) received guideline-concordant treatment. Receipt of guideline-concordant treatment was less common among women with nonendometrioid histology (OR = 0.24, 95% CI = 0.13-0.45) but was more common among women living in the Midwest (OR = 2.09, 95% CI = 1.06-4.12) or West (OR = 3.02, 95% CI = 1.49-6.13) compared to the Northeast. In Cox regression models adjusted for age, histology and stage, receipt of guideline-concordant EC treatment was borderline associated with improved overall survival (HR = 0.80, 95% CI = 0.60-1.01) in the overall population. Guideline-concordant treatment was also linked with better overall survival among women with low-grade uterine-confined endometrioid EC or widely metastatic endometrioid EC. Guideline-concordant treatment varies by some patient characteristics and those women in receipt of guideline-concordant care had borderline improved survival. Studies evaluating regional differences in treatment along with randomized clinical trials to determine appropriate treatment regimens for women with aggressive tumor characteristics are warranted.