The Impact of a Prior Diagnosis of Barrett's Esophagus on Esophageal Adenocarcinoma Survival.

OBJECTIVES: Endoscopic surveillance of patients with Barrett's Esophagus (BE) is recommended to detect esophageal adenocarcinoma (EAC) and its dysplasia precursors, but survival benefits are unclear. Using Surveillance, Epidemiology, and End Results (SEER) and linked Medicare data, we sought to determine the impact of a prior BE diagnosis on survival in patients with EAC. METHODS: Our analysis focused on patients over age 65 with primary EAC diagnosed in a SEER region from 2000-2011 and enrolled in Medicare. We identified patients with preexisting BE prior to EAC diagnosis and compared this group to EAC patients without a prior BE diagnosis. A Cox Proportional Hazards model compared survival and included variables such as age, sex, cancer stage, treatment, and medical comorbidities. RESULTS: Among 4,978 SEER-Medicare patients identified with EAC, 577 (12%) had preexisting BE; 4,401 (88%) did not. BE patients had overall lower stage (28.5% stage I vs. 12.8% stage IV) than those without preexisting BE (16.4% stage I vs. 30.6% stage IV). Overall survival was better among patients in the BE group (hazard ratio (HR), 0.56; 95% confidence interval (CI), 0.50-0.61); this benefit persisted in the adjusted model (HR, 0.72; 95%, 0.65-0.80). After adjusting for lead-time bias, the HRs attenuated to the null, with an unadjusted HR of 0.96 (95% CI: 0.86-1.05, P = 0.39) and adjusted HR of 0.99 (CI: 0.89-1.10, P = 0.92). CONCLUSIONS: Survival outcomes in patients with a BE diagnosis prior to EAC were statistically better in both the unadjusted and adjusted Cox proportional hazards model. However, this benefit appears to be predominantly lead-time and length-time bias.