Response to neoadjuvant chemotherapy and impact on survival for resected gastric cancer.

Abstract

122 Background: This study assesses the survival impact of perioperative chemotherapy, with further analysis of pathologic response to neoadjuvant chemotherapy (NAC), in patients undergoing gastrectomy for gastric cancer (GC) in a large US sample. Methods: Using the 2003-2012 ACS National Cancer Database, 16,128 patients underwent gastrectomy for cancer. Treatment groups were categorized as: NAC, adjuvant chemotherapy, and surgery only. Patients receiving NAC were further categorized as: down-staged, no response, and disease progression. Univariate and multivariate analyses were performed to estimate the impact of treatment on overall survival. Results: Of patients undergoing gastrectomy, 36.6% received NAC, 19.5% received adjuvant chemotherapy, and 43.9% underwent surgery only. Median time of survival was longer in patients with more advanced disease who underwent either NAC or adjuvant chemotherapy versus surgery alone (see Table). In multivariate analysis, patients who received NAC had 20% lower hazard of death than surgery only patients (HR = 0.80, p < 0.0001). Within the NAC cohort (N = 5,909), 47.7% were down-staged, 36.5% had no response, and 15.7% demonstrated disease progression. Having a pathologic response to NAC was associated with having private insurance (OR = 1.22, p < 0.0001), higher socioeconomic status (OR = 1.21, p = 0.003), treatment in the central US (p < 0.0001, both), and undergoing proximal gastrectomy (OR = 1.59, p < 0.0001). Among patients who received NAC, median time of survival was longer if NAC down-staged patients to stages 0 or 1, with no survival difference in advanced stage disease. Conclusions: Neoadjuvant chemotherapy elicits a survival benefit in patients with advanced GC. Pathologic response is achieved in nearly half of patients undergoing NAC and is associated with improved survival, although only when down-staging to early stage disease. [Table: see text] [Table: see text]