A Benefit Population Atlas of nICT Versus nCT for LAGC

Identifying Optimal Responders: A Benefit Population Atlas of Neoadjuvant Immunochemotherapy Versus Chemotherapy for Locally Advanced Gastric Cancer

The purpose of this observational study is to evaluate the impact of different neoadjuvant therapies on patients with locally advanced gastric cancer. The primary question it aims to address is: Which patient populations benefit most from neoadjuvant immunochemotherapy versus neoadjuvant chemotherapy in locally advanced gastric cancer?

This study aims to: 1. Compare pCR rates and TRG between neoadjuvant chemotherapy (two-drug vs. three-drug) and neoadjuvant immunochemotherapy; 2. Explore efficacy differences across subgroups; 3. Provide evidence-based guidance for individualized neoadjuvant treatment.

Inclusion Criteria:

Eligible patients had pathologically confirmed adenocarcinoma, imaging-confirmed resectable LAGC (cT2-4aN0-3M0, AJCC 8th), no distant metastases, and completed protocol-specified neoadjuvant therapy (nICT: PD-1/PD-L1 inhibitors plus two-drug chemotherapy; nCT: two-drug [SOX/XELOX] or three-drug [FLOT/DCF] chemotherapy) with ECOG 0-1.

Exclusion Criteria:

Exclusion criteria included incomplete neoadjuvant therapy, non-radical surgery, other malignancies, active autoimmune diseases/immunosuppressant use, missing key data, or inadequate follow-up (<3 months without documented events).