Optimal response population after neoadjuvant therapy for patients with locally advanced gastric cancer: A multicenter study.

OBJECTIVE

Pathologic complete response (pCR) following neoadjuvant therapy (NAT) for gastric cancer (GC) is rare but associated with a favorable prognosis. This study aims to reassess the optimal response population (ORP) following NAT by evaluating the prognostic outcomes associated with various T and N stages, utilizing multicenter data from China.

METHODS

Patients who underwent NAT following radical gastrectomy at 10 tertiary hospitals in China between 2008 and 2021 were included. The ORP was introduced to explore the disease-free survival (DFS), overall survival (OS), recurrence patterns, and influencing factors following propensity score matching (PSM).

RESULTS

A total of 1,076 patients were enrolled in this study (median follow-up period: 60 months). We defined ORP as a pCR or tumor infiltration of the mucosal or submucosal layer without lymph node metastasis (pCR or ypT1N0) after NAT. The ORP group comprised 136 patients (12.6%), while the non-ORP group comprised 940 patients (87.4%). After applying a 1:4 PSM, we obtained an ORP group of 136 patients and non-ORP group of 544 patients. Survival analysis demonstrated that both the 3-year OS (before PSM: 89.0% 55.0%, P<0.001; after PSM: 89.0% 55.4%, P<0.001) and DFS (before PSM: 85.8% 49.7%, P<0.001; after PSM: 85.8% 50.6%, P<0.001) were significantly superior in the ORP group compared to that in the non-ORP group. Remarkably, adjuvant chemotherapy did not impact the prognosis of patients in the ORP group (3-year OS: 89.0% 89.7%, P=0.988; 3-year DFS: 84.9% 89.7%, P=0.700).

CONCLUSIONS

This study reevaluates patients with ORP following NAT, providing a more comprehensive and accurate depiction of the potential beneficiary group and survival outcomes in patients with locally advanced GC.