Real-world outcomes of biomarker-guided multidisciplinary management in localized and metastatic gastric cancer.

Abstract

e16060 Background: Gastric cancer (GC) is a biologically heterogeneous disease with limited prognosis, particularly in advanced stages. In routine clinical practice, treatment decisions are commonly discussed within multidisciplinary teams (MDTs) integrating clinical, pathological, and molecular information. However, real-world data describing outcomes of patients managed through standard MDT discussions across different disease settings remain limited. Methods: We retrospectively evaluated 172 consecutive patients with gastric or gastroesophageal junction adenocarcinoma (96 localized/neoadjuvant, 76 metastatic) discussed within the institution’s standard weekly MDT for gastric cancer between January 2018 and December 2024. Data were collected retrospectively from institutional databases and medical records; MDT evaluation included tumor stage, ECOG performance status, comorbidities, and molecular profiling (HER2, PD-L1 combined positive score [CPS], microsatellite instability [MSI]). Neoadjuvant treatment consisted of platinum–fluoropyrimidine–based chemotherapy with or without docetaxel (FOLFOX or FLOT), followed by surgery when feasible. In metastatic disease, treatment selection included chemotherapy alone or combined with targeted therapy or immunotherapy according to molecular status. The primary endpoint was overall survival (OS); secondary endpoints included progression-free survival (PFS), R0 resection rate, and treatment allocation. Results: Median age was 70 years (range 50–85); 59% were male. ECOG PS was 0–1 in 68% and PS 2 in 32% of patients. Molecular alterations included HER2 positivity in 18%, PD-L1 CPS ≥5 in 44%, and MSI-high status in 9%. In the localized/neoadjuvant cohort, MDT-guided management was associated with an R0 resection rate of 76%, median PFS of 14.5 months, and median OS not reached after a median follow-up of 32 months. In metastatic patients, MDT-guided treatment selection was associated with a median PFS of 7.2 months and median OS of 15.2 months, compared with 10.4 months in patients treated prior to routine MDT implementation. Objective response rate was 48% and disease control rate 68%. Grade ≥3 adverse events occurred in 24% of patients, mainly hematologic; no unexpected toxicities were observed. On multivariate analysis, MDT discussion was associated with improved OS (HR 0.66, 95% CI 0.50–0.87). Conclusions: In this real-world experience, systematic discussion within a standard weekly MDT integrating molecular profiling was associated with optimized treatment allocation and favorable clinical outcomes in both localized and metastatic GC. These findings support the role of a structured multidisciplinary discussion in routine clinical practice.