Lack of National Adoption of Evidence-Based Treatment for Resectable Gastric Adenocarcinoma

BACKGROUND: Level 1 evidence for multimodal treatment of resectable gastric adenocarcinoma from the Intergroup 0116 (2001) and MAGIC (2006) trials demonstrated survival benefit of adjuvant chemoradiation (CRT) and perioperative chemotherapy, respectively. We evaluated the adoption of evidence-based treatment in the post-MAGIC era and its impact on survival. METHODS: A total of 7058 patients with resectable gastric adenocarcinoma undergoing definitive surgical resection between 2004 and 2015 were analyzed using the National Cancer Database. RESULTS: Over the study period, the proportion of patients receiving adjuvant CRT decreased from 19.1% to 9.1%, while perioperative chemotherapy increased from 1.9% to 28.6%. Utilization of perioperative chemotherapy surpassed adjuvant CRT in 2011. Evidence-based treatment (either perioperative chemotherapy or adjuvant CRT) had better overall survival (OS) than other treatments for clinical stage II–III patients (p < 0.05). On multivariate analysis of the whole study period, evidence-based treatments were associated with better OS (HR 0.67 [0.60–0.74], p < 0.05). Only 360/1262 (28.5%) patients in the perioperative chemotherapy group completed postoperative therapy, which was associated with improved OS (p < 0.05). For clinical stage III patients (n = 2402), only 806 (33.6%) received evidence-based treatment, while 487 (22.2%) underwent surgery alone. On multivariate analysis of these patients between 2010 and 2015, both perioperative chemotherapy (HR 0.49 [0.35–0.68]) and adjuvant CRT (HR 0.31 [0.21–0.44]) were associated with better OS than surgery alone (p < 0.05). CONCLUSIONS: Since the INT-0116 and MAGIC trials, utilization of evidence-based treatments for resectable gastric adenocarcinoma has increased, with perioperative chemotherapy surpassing adjuvant CRT as the preferred practice. However, overall utilization of these regimens remains quite low nationally despite association with improved OS.