Abstract
OBJECTIVE: Adenocarcinoma of the esophagogastric junction (AEJ) is a relatively rare malignancy in Western countries whose specific clinicopathological characteristics and associated prognosis have not been comprehensively described. METHODS: Data on patients with AEJ between 2005 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were extracted, evaluated, and compared with patients with gastric cancer (GC) in general. Overall survival (OS) was evaluated using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox proportional hazards regression model to identify risk factors predictive for OS, and the results were used to construct a nomogram to predict 1-, 3-, and 5-year OS among patients with AEJ. RESULTS: A total of 8013 patients diagnosed with AEJ were identified from the records of 30,179 patients with GC. The mean age was 65.4 (SD = 12.0) years, 79.5% were men, 87.2% were Caucasian, 91.5% were moderately-to-poorly differentiated, 34.4% had AJCC stage I AEJ, and 28.8% had stage IV. The median OS was 18 months, and the 5-year OS was 25.8% (95% CI: 24.8-26.8%). Fewer patients with AEJ had undergone surgical resection, fewer had T+ and N+ (N2~N3) disease (P < 0.001), and fewer had distant metastases compared to the patients with GC (P < 0.05). In the univariate and multivariate analyses, age, race, summary stage, N stage, M stage, and surgery were identified as independent risk factors. The nomogram had a calibration index of 0.726. CONCLUSION: AEJ was found to have distinct clinicopathological characteristics. Age, race, summary stage, N stage, M stage, and surgery were independently associated with OS. The nomogram accurately predicted 1-, 3-, and 5-year OS rates.