Perioperative Chemotherapy Versus Postoperative Chemoradiotherapy in Patients With Resectable Gastric/Gastroesophageal Junction Adenocarcinomas: A Survival Analysis of 5058 Patients

BACKGROUND: Both perioperative chemotherapy (PECT) and postoperative chemoradiotherapy (POCRT) have a significant survival advantage over surgery alone for the treatment of patients with gastric cancer. However, to the best of our knowledge, these regimens have not been compared in a randomized clinical trial. The purpose of the current observational study was to compare overall survival among patients receiving PECT versus POCRT for the treatment of gastric/gastroesophageal junction (GEJ) adenocarcinomas. METHODS: Patients with resected clinical American Joint Committee on Cancer TNM stage II or III adenocarcinomas of the stomach or GEJ from 2004 through 2013 were identified utilizing the National Cancer Data Base. Hazard ratios (HRs), 95% confidence intervals, and P values were computed using a Cox proportional hazards procedure. Multivariable models were adjusted for treatment regimen, age, race, ethnicity, tumor size, TNM stage, Charlson comorbidity index, and tumor grade. RESULTS: Patients receiving PECT had a 72% survival advantage compared with those treated with POCRT (5058 patients; HR, 0.58 [adjusted P <.0001]). The 5-year actuarial survival rate for PECT was 44% compared with 38% for POCRT. A statistically significant survival advantage for PECT also was observed when the analysis was stratified by clinical stage of disease (stage II [3192 patients]: adjusted HR, 0.79 [P=.041]; and stage III [1866 patients]: adjusted HR, 0.49 [P <.0001]). This benefit was greatest among patients with lymph node-positive disease who converted to lymph node-negative status with PECT. CONCLUSIONS: In this large series of patients with stage II/III resected gastric/GEJ adenocarcinomas from > 1500 American College of Surgeons Commission on Cancer-accredited facilities, patients receiving PECT were shown to survive longer than those receiving POCRT. (c) 2017 American Cancer Society.