Intestinal Subtype as a Biomarker of Response to Neoadjuvant Immunochemotherapy in Locally Advanced Gastric Adenocarcinoma: Insights from a Prospective Phase II Trial.

Purpose: Neoadjuvant immunochemotherapy (NAIC) markedly induces pathologic regression in locally advanced gastric adenocarcinoma. However, specific biomarkers are still lacking to effectively identify the beneficiary patients for NAIC.

Patients And Methods: A prospective, single-arm, phase II study was conducted to treat locally advanced gastric adenocarcinoma with NAIC (NCT05515796).

Reduced intestinal-to-diffuse conversion and immunosuppressive responses underlie superiority of neoadjuvant immunochemotherapy in gastric adenocarcinoma.

Neoadjuvant immunochemotherapy (NAIC) achieves superior clinical benefits over neoadjuvant chemotherapy (NAC) in multiple types of human cancers, including gastric adenocarcinoma (GAC). However, it is poorly understood how the malignant epithelial cells and tumor immune microenvironment (TIME) might respond distinctly to NAIC and NAC that underlies therapeutic efficacy. Here treatment-naive and paired tumor tissues from multiple centers were subjected to pathological, immunological, and transcriptomic analysis.