Postoperative morbidity after gastrectomy for gastric cancer: risk factors and survival outcomes in a Western single-center cohort study - An evaluation of the GASTRODATA documentation standard.

INTRODUCTION: Gastrectomy for cancer remains a high-risk surgical procedure associated with substantial postoperative morbidity and mortality. Standardized assessment of postoperative complications is therefore essential. The Gastrectomy Complications Consensus Group (GCCG) classification, validated within the GASTRODATA registry, was developed to enable uniform and clinically relevant reporting of complications after gastrectomy. The aim of this study was to identify preoperative risk factors and postoperative complications following gastrectomy for cancer, to evaluate their association with long-term outcomes, and to assess the applicability of the GASTRODATA registry in a high-volume Western cohort. METHODS: This single-center retrospective cohort study included 435 patients who underwent partial or total gastrectomy for gastric or gastroesophageal junction (GEJ) cancer between 2005 and 2022. Postoperative complications were documented using the GASTRODATA standard and established complication scores (Clavien-Dindo classification and Comprehensive Complication Index (CCI)). Univariable comparisons and multivariable regression models, Kaplan-Meier estimates and Cox regression regarding Overall- and Recurrence-free were performed. RESULTS: Overall postoperative complications occurred in 48.0%, with major complications (Clavien-Dindo ≥ III) observed in 30.1%. GASTRODATA-defined complication rates ranged from 0% to 21.1%, with non-specified postoperative surgical (21.1%) and general infections (13.6%) being most common. Major postoperative complications were significantly associated with ASA classification (p = 0.013), tumor localization (p < 0.001), T category (p = 0.023), Lauren classification (p = 0.030), and type of operation (p = 0.026). In multivariable logistic regression, tumor localization at the gastroesophageal junction (p = 0.002), diffuse (OR 2.247; p = 0.023) and mixed (OR2.880; p = 0.006) Lauren Subtype remained independently associated. Major postoperative complications were associated with reduced overall survival in unadjusted analyses (p = 0.018). In multivariable Cox models, complications were not independently associated with either outcome, whereas tumor stage remained independently associated (p < 0.001). CONCLUSION: Postoperative morbidity after gastrectomy remains common in Western populations and is influenced by patient- and tumor-related factors. Long-term oncological outcomes are primarily determined by tumor stage rather than postoperative complications. Although applicable in clinical practice, the GASTRODATA standard shows limitations in capturing relevant morbidity patterns.