Risk factors for remnant gastric cancer after distal gastrectomy for gastric cancer: a retrospective database review

Background: The number of patients with remnant gastric cancer (RGC) following gastrectomy for gastric cancer (GC) is increasing due to the increasing number of patients undergoing function-preserving gastrectomy and improved outcomes for patients with GC. A few studies involving a small number of cases reported male sex, old age, differentiated type, tumor depth and synchronous multiple GC were associated with RGC development. However, the risk factors for RGC development had not been fully understood. This study aimed to examine the clinicopathological features, followed up patients with GC after they underwent distal gastrectomy (DG), and evaluated the potential risk factors for RGC development. Methods: A retrospective database review of 438 patients who underwent DG for GC at a single institution, from 2006 to 2017, was conducted. We investigated the relationship of clinicopathological features, operative findings, and postoperative course with RGC development was estimated using Cox proportional hazard analysis. The cumulative incidences of RGC were calculated using the Kaplan-Meier method. Results: We retrospectively analyzed 405 cases. The median patient age was 69 years, and the patient cohort consisted of 263 men and 142 women. The Billroth-I reconstruction method was used in 204 cases, Billroth-II method was used in 3 cases, and Roux-en Y method was used in 198 cases. RGC was diagnosed in 11 of the 405 patients. The median follow-up period was 5 years. The cumulative incidences of RGC calculated by the Kaplan-Meier method were 3.0%, 4.1%, and 10.5% at 5, 10, and 15 years after DG, respectively. During the initial surgery, differentiated type was significantly associated with RGC development [hazard ratio (HR): 4.71, 95% confidence interval (CI): 1.02- 21.80, P=0.05]. Male sex (HR: 2.97, 95% CI: 0.64-13.75, P=0.16), old age (>= 70 years) (HR: 2.72, 95% CI: 0.78-9.47, P=0.11), and synchronous multiple GC (HR: 1.31, 95% CI: 0.28-6.08, P=0.73) were not associated with RGC development. Conclusions: Patients who have undergone DG for differentiated type GC were statistically significantly associated with developing RGC. Intensive endoscopic surveillance would be needed for the patients who underwent DG for differentiated type GC.