Underuse of Surgery Accounts for Racial Disparities in Esophageal Cancer Survival Times: A Matched Cohort Study

Abstract

There are racial disparities in survival times of patients with esophageal cancer. We examined the sequential effects of characteristics, diagnosis, and treatment-related factors on the disparity in survival times of black vs white patients with esophageal cancer. We identified 1900 black and 15,523 non-Hispanic white (NHW) patients, 65 years or older, diagnosed with esophageal squamous cell carcinoma or esophageal adenocarcinoma from 1994 through 2011 in the Surveillance Epidemiology and End Results (SEER)-Medicare database. Patients were followed up until death or December 31, 2012. Three sets of 1900 NHW patients were matched sequentially to the same set of 1900 black patients, based on demographics (age, sex, year of diagnosis, and SEER site), presentation (demographics plus cancer stage, grade, and comorbidity), and treatment (presentation variables plus surgery, chemotherapy, or radiation therapy). The absolute difference in 5-year survival between black patients (13.3%) and NHW patients (18.4%) was 5.1% (95% CI, 2.3%-7.7%; P= .001) in the demographics match. After we matched for presentation, the difference in 5-year survival was reduced to 2.3% (95% CI, 0.3%-4.8%), but remained statistically significant (P= .04). Additional matching of patients on treatment-related factors eliminated the racial difference in 5-year survival (P= .59). Among patients matched for disease presentation, only 10.8% of black patients underwent surgery, compared with 22.8% of NHW patients (P < .001). Histology, tumor location, socioeconomic status, chemotherapy, and radiation therapy each were associated with the receipt of surgery. None of these factors, however, could explain the racial difference in the receipt of surgery. In the SEER-Medicare database, underuse of surgical treatment can account for the disparities in survival times between black and NHW patients with esophageal cancer.