Trends in the use of evidence-based therapy for resectable gastric cancer.

Background And Objectives: Two pivotal randomized controlled trials (RCTs), the Intergroup (INT-0116) and Medical Research Council Adjuvant Gastric Infusional Chemotherapy (MAGIC) trials, demonstrated a survival benefit of multimodality therapy in patients with resectable gastric cancer. The purpose of this study was to determine utilization rates of these treatment regimens in the United States and to identify factors associated with receipt of evidence-based care.

Methods: We performed a retrospective cohort study of patients with Stage IB-IV (M0) gastric adenocarcinoma who underwent resection from 1991 to 2009 using the linked SEER-Medicare database.

Results: Only 19.1% of patients received post-operative chemoradiation therapy (CRT), and 1.9% received peri-operative chemotherapy; most patients underwent surgery alone (60.9%). Patients with more advanced stage, younger age, and fewer comorbidities were more likely to receive evidence-based care. We found no association between National Cancer Institute (NCI) designation and delivery of multimodality therapy. However, patients who underwent medical oncology consultation were much more likely to receive evidence-based treatment (OR 3.10, 95% CI 2.35-4.09).

Conclusions: Rates of peri-operative chemotherapy and post-operative CRT in patients with resected gastric cancer remain remarkably low, despite high-quality RCT evidence demonstrating their benefit. Furthermore, NCI designation does not appear to be associated with administration of evidence-based treatment.