Multimodality Treatment of T4 Gastric Cancer in the United States: Utilization Trends and Impact on Survival.

Abstract

National guidelines advocate use of multimodality therapy (MMT) for treatment of T4 gastric cancer (T4GC). Prior studies demonstrate poor compliance with these guidelines. We sought to assess treatment trends and association between different treatment approaches and overall survival (OS) in a large cohort of U.S. Patients diagnosed with clinical T4 gastric adenocarcinoma were selected from the National Cancer Data Base (1998-2011). Temporal trends, risk factors associated with failure to receive treatment, and effect of treatments on OS were assessed. Of 4369 patients with T4GC, only 15 % (n = 652) received MMT. Treatment with MMT increased over time, and was utilized in 25 % of patients after 2006. Older age, African American race, nonprivate insurance, proximal tumor location, and clinical node-negative disease were associated with failure to receive surgery; older age, female sex, poorly differentiated tumor grade, clinical node-negative disease, and prolonged postoperative length of stay were associated with failure to complete MMT in patients who underwent surgical resection. Median OS was longest in patients receiving MMT (19.2 months), and was similarly poor in patients undergoing surgical resection (9.0 months) or nonsurgical therapy (8.3 months; p < 0.001). Median OS was longer in patients receiving neoadjuvant therapy compared to patients receiving adjuvant therapy (27.8 vs. 16.6 months; p = 0.004). Treatment with neoadjuvant MMT is increasing and is associated with prolonged survival. Surgery alone and chemotherapy with or without radiotherapy without resection are associated with similarly poor outcomes. Appropriate treatment sequencing may facilitate delivery of MMT and improve outcomes in patients with T4GC.