Scoring system for predicting the prognosis of elderly gastric cancer patients after endoscopic submucosal dissection

Objectives Comprehensive assessments of the long-term outcomes of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) in the elderly are unavailable. We aimed to create a scoring system to predict the long-term prognosis after ESD for EGC among patients aged >= 75 years. Methods We conducted retrospective studies of two cohorts: a single-center cohort (2006-2011) for developing the scoring system, and a multicenter cohort for validating the developed system (2012-2016). In the development cohort, factors related to death after ESD were identified using multivariable Cox regression analysis, and a predictive scoring system was developed. In the validation cohort, the scoring system was validated in 295 patients. Results In the development cohort, Charlson comorbidity index (CCI) >= 3 (hazard ratio [HR] 3.017), high psoas muscle index (PMI) (HR 2.206), and age >= 80 years (HR 1.978) were significantly related to overall survival after ESD. Therefore, high CCI, low PMI, and age >= 80 years were assigned 1 point each. The patients were categorized into low (<= 1 point) and high (>= 2 points) score groups based on their total scores. In the validation cohort, 184 and 111 patients were assigned to the low- and high-score groups, respectively. In comparisons based on Kaplan-Meier curves, the 5-year survival rate was 91.5% in the low-score group and 57.8% in the high-score group (log-rank test; P < 0.001). Conclusion Our scoring system including high CCI, low PMI, and age >= 80 years could stratify the long-term prognosis of elderly patients aged >= 75 years after ESD for EGC.