Multivisceral Resection for Locally Advanced Gastric Cancer.

Background: Locally advanced gastric cancer (LAGC) presents a therapeutic dilemma, particularly as it often involves adjacent organs through desmoplasia or true pathologic invasion. To obtain a margin-negative resection, these tumors require en bloc gastrectomy with multivisceral resection (G+MVR), and contention remains regarding its safety and oncologic benefit.

Methods: We used the National Cancer Database to retrospectively evaluate the short- and long-term outcomes of patients with LAGC treated in the USA between 2004 and 2016. Associations with margin status and perioperative outcomes were calculated using logistic regression. Survival was estimated using Cox proportional hazards regression and the Kaplan-Meier method.

Results: Overall, 785 pathologic stage T4b (pT4b) patients diagnosed with LAGC underwent gastrectomy (n = 438) or G+MVR (n = 347). There was no association between G+MVR and short- or long-term mortality. Positive resection margins (HR 1.68, 95% CI 1.40-2.03), the presence of nodal disease (HRs 1.46-1.50), treatment at a high-volume center (HR 0.76, 95% CI 0.68-0.85), and the receipt of adjuvant chemotherapy (HR 0.64, 95% CI 0.51-0.80) were independently associated with overall survival. Diffuse-type histology was associated with higher rates of an R1 resection (OR 3.60, 95% CI 2.20-5.87). Perioperative and long-term survival metrics were comparable between patients with pT4a and pT4b LAGC who underwent a margin-negative G+MVR. Undergoing a margin-negative G+MVR imparted a 6-month survival benefit over non-curative gastrectomy alone (p < 0.001).

Conclusions: Our study demonstrates the safety and long-term feasibility of G+MVR for disease clearance in well-selected patients with LAGC, and we advocate for their referral to high-volume centers for optimal care.