What determines complications and prognosis among patients subject to multivisceral resections for locally advanced gastric cancer?

BACKGROUND: Locally advanced gastric cancer (GC) extending to the surrounding tissues may require a multivisceral resection (MVR) to provide the best chance of cure. However, little is known about how the extent of organ resection affects the risks and benefits of surgery. METHODS: An electronic database of patients treated between 1996 and 2020 in an academic surgical centre was reviewed. MVRs were defined as partial or total gastrectomy combined with splenectomy, distal pancreatectomy, or partial colectomy. RESULTS: Suspected intraoperative tumour invasion of perigastric organs (cT4b) was found in 298 of 1476 patients with non-metastatic GC, and 218 were subject to MVRs, including the spleen (n = 126), pancreas (n = 51), and colon (n = 41). MVRs were associated with higher proportions of surgical and general complications, but not mortality. A nomogram was developed to predict the risk of major postoperative morbidity (Clavien–Dindo’s grade ≥ 3a), and the highest odds ratio for major morbidity identified by logistic regression modelling was found for distal pancreatectomy (2.53, 95% CI 1.23–5.19, P = 0.012) and colectomy (2.29, 95% CI 1.04–5.09, P = 0.035). Margin-positive resections were identified by the Cox proportional hazards model as the most important risk factor for patients’ survival (hazard ratio 1.47, 95% CI 1.10–1.97). The extent of organ resection did not affect prognosis, but a MVR was the only factor reducing the risk of margin positivity (OR 0.44, 95% CI 0.21–0.87). CONCLUSIONS: The risk of multivisceral resections is associated with the organ being removed, but only MVRs increase the odds of complete tumour clearance for locally advanced gastric cancer. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00423-023-03187-7.