Comparison on Clinicopathological Features, Treatments and Prognosis between Proximal Gastric Cancer and Distal Gastric Cancer: A National Cancer Data Base Analysis

Background: The aim of this study was to examine the differences in clinicopathological features, treatment strategies and prognosis between patients with proximal gastric cancer (PGC) and distal gastric cancer (DGC). Methods: Patients with gastric adenocarcinoma were identified from the National Cancer Database during the years 2004-2015. Survival analysis was performed via Kaplan-Meier and Cox proportional hazards models. Results: A total of 97,060 patients were identified with gastric adenocarcinoma. DGC was associated with older age, more advanced tumor stage, and poorly differentiated tumors compared with PGC (all p<0.01). In the multivariate analysis, patients with DGC had a worse prognosis compared with those with PGC. In early and locally advanced stage, the prognosis of DGC was better compared with PGC. In distant metastasis stage, the prognosis of DGC was worse compared with PGC. Compared with patients underwent gastrectomy who received adjuvant therapy (AT) in locally advanced stage, a survival benefit was seen for DGC patients who received neoadjuvant therapy (NAT) or NAT plus AT, whereas PGC patients with locally advanced disease did not share this result (p>0.05). Conclusion: PGC and DGC differed in their clinicopathologic characteristics and prognosis and heterogeneity may be due to differences in tumor biology. Tumor location should be taken into consideration when stratifying patients for optimal therapeutic strategies.