Baseline features predicting receipt of chemotherapy in metastatic esophageal cancer: A National Cancer Database analysis of 12,370 patients.

Abstract

316 Background: We investigated predictors for chemotherapy (CTX) and prognostic variables in a large metastatic esophageal cancer (mEC) patient data set. Methods: We interrogated the National Cancer Database between 2004-2015 and included patients (pts) with M1 disease who had known CTX status (received or did not receive CTX). Univariable and multivariable analyses were performed, and a logistic regression model was used to estimate the effect of CTX with adjustment for potential confounders. Results: We included 12,370 mEC patients with available CTX status for multivariable analyses. Predictors for CTX treatment included year of diagnosis 2010-2014 (odds ratio (OR) 1.29, 95% confidence interval (CI) 1.17-1.43), median income > $46,000 (OR 1.49, 1.27-1.75), and node-positivity (OR 1.35, 1.20-1.52; all p < 0.05), while female gender (OR 0.86, 0.76-0.98), black race (OR 0.76, 0.67-0.93), uninsured (OR 0.41, 0.33-0.52), and Charlson Comorbidity Index (CCI) ≥2 (OR 0.61, 0.50-0.74) predicted for lower odds of receiving CTX (all p < 0.05). Median OS for pts receiving CTX was 9.53 mos (9.33-9.72) vs. 2.43 mos (2.27-2.60) with no CTX (p < 0.001). Modeling the effect of CTX to OS using a time-dependent coefficient showed that CTX was associated with improved OS up to 10 months, after which there is no significant effect on OS. Independent predictors of OS included treatment at an academic center (hazard ratio (HR) 0.91, 0.87-0.94), CCI ≥2 (HR 1.16, 1.07-1.26), and uninsured status (HR 1.20, 1.09-1.31). Conclusions: We identified several predictors for receipt of CTX and OS in pts with mEC. The benefit of CTX on OS is time-dependent and favors early initiation. Focused outreach in lower income and underinsured patients is critical as receipt of CTX is associated with improved OS.