Procedure volume of gastric cancer resections versus 5-year survival

Aim: We used nationwide, population-based data to examine associations between hospital and surgeon volumes of gastric cancer resections and their patients' short-term and long-term survival likelihood. Methods: The study uses 1997-1999 inpatient claims data from Taiwan's National Health Insurance linked to "cause of death" data for 1997-2004. The total cohort of 6909 gastric cancer resection patients were categorized by their surgeon's/hospital's procedure volume, and examined for differences in 6-month mortality and 5-year mortality (post 6 months), by procedure volume, using Cox proportional hazard regressions, adjusting for surgeon, hospital and patient characteristics. We hypothesized that surgeons' case volume and age but not hospital volume will predict short-term and long-term survival. Results: Adjusted estimates show that increasing surgeon volume predicts better 6-month survival (adjusted mortality hazard ratio = 1.3 for low-volume surgeons relative to very high-volume surgeons; p <0.01) and 5-year survival (adjusted mortality hazard ratios = 1.3; p <0.001 for low-volume; 1.2 with p <0.01 for medium volume) and increasing surgeon's age (adjusted hazards ratio = 1.4 for age <41 years relative to 41-50 years; p ≤ 0.001; 0.8 for ≥51 years relative to 41-50 years; p <0.05). In hospital volume regressions, surgeon's age is a consistent and significant predictor, not hospital volume. Findings suggest a key role of experience in surgical skill and sensitivity for early stage diagnosis in gastric cancer survival. Conclusions: Although a key study limitation is the lack of cancer stage data, the pattern of findings suggests that experienced surgeons have relatively better survival outcomes among gastric cancer patients.