Survival Outcome and Prognostic Factors of Remnant Gastric Cancer: A Propensity Score-Matched Analysis

Abstract Purpose. Studies on survival and prognostic factors in individuals with remnant gastric cancer (RGC) after gastric cancer (GC) are rare. It is debatable whether prognosis of RGC after GC is worse than that of only primary gastric cancer (OPGC). Methods. We retrospectively collected data from the Surveillance, Epidemiology, and End Results database among patients who underwent GC surgery in 1988–2020. Propensity score matching (PSM) was conducted to balance baseline characteristics. Kaplan-Meier survival analysis was performed to compare their overall survival (OS) and disease-specific survival (DSS). Multivariable Cox analyses were performed to identify the independent prognostic factors for RGC. Results. 76 patients with RGC and 32763 patients with OPGC were included and analyzed. After balancing the baseline characteristics by PSM, no significant difference existed between OPGC and RGC groups in both OS (p = 0.65) and DSS (p = 0.35). Fixed-time analyses also showed no difference between the two groups for the 5-year (60.0%, RGC vs. 53.3%, OPGC, p = 0.38) and 10-year DSS (56.7%, RGC vs. 48.3%, OPGC, p = 0.34) DSS. Multivariate analysis revealed that area of lower income (<$55000), cardiac tumor, deeper invasion (T3-4), higher grade (G3) and not receiving chemotherapy were independent risk factors for DSS in patients with RGC. Conclusion. The prognosis of RGC following GC was comparable to that of OPGC. The independent prognostic factors for RGC are similar to those established for OPGC. Our findings suggest that RGC might be the same entity to OPGC and curative resection should be considered in selected patients.