Gastric cancer surgery in high volume university medical centers influences long-term survival

Short-term gastric cancer surgery outcomes depend greatly on hospital surgical volume, whereas long-term survival studies show conflicting results. This study evaluated the effect of surgical volume on the long-term survival of patients who underwent surgery for gastric cancer in Slovenia.

A retrospective cohort analysis was performed using the Slovenian Cancer Registry data. Patients diagnosed between 2016 and 2020 who underwent gastric cancer surgery were categorized into high- and low-volume centers. High-volume centers were defined, as the two University Medical Centers (Ljubljana and Maribor), which together treated 76.4 % of all patients during the study period. Survival analysis was conducted using Kaplan-Meier overall survival and Pohar-Perme net survival estimators, with predefined subgroup analysis. Cox proportional hazards models assessed the independent association between center volume and overall survival.

Among the 652 patients, 498 (76.4 %) underwent surgery at high-volume centers (44,2-55,4 mean surgeries/year), which demonstrated higher median overall survival (4.9 vs. 3.2 years) and improved overall and net 1-, 3-, and 5-year survival rates compared with low-volume centers (0,2-6,2 mean surgeries/year). This differences persisted in stratified analyses by stage and neoadjuvant therapy but not by age. In multivariable Cox analysis the hazard ratio remained directionally favorable for high-volume centers but was not statistically significant.

Overall, high-volume centers were consistently associated with better long-term survival after gastric cancer surgery in Slovenia, supporting further evaluation of centralization strategies. Future policies should aim to balance the benefits of centralization while maintaining equitable access to timely and high-quality surgical treatment, regardless of location or socioeconomic status.