Long-term survival outcome of locally advanced gastric cancer patients who achieved a pathological complete response to neoadjuvant chemotherapy.

Background: Long-term outcome of patients with locally advanced gastric cancer (LAGC) who achieved a pathological complete response (pCR) was scarcely discussed, and never had the factors affecting the prognosis of pCR patients been investigated.

Methods: We retrospectively reviewed all patients who achieved a pCR to neoadjuvant chemotherapy (NAC) in Jinling Hospital. The 3- and 5-year overall survival (OS) and progression-free survival (PFS) were calculated with the Kaplan-Meier method. Meanwhile, univariate and multivariate COX regression analysis was applied to identify prognostic factors affecting patients' survival.

Results: A total of 37 consecutive LAGC patients with pCR were included. The 3- and 5-year OS rates were 88.8% and 78.6%, and the 3- and 5-year PFS rates were 86.5% and 75.8%. In the multivariate COX model, NAC duration of more than 3 cycles (HR 0.11 [0.02-0.62], P = 0.013) and poorly differentiated tumor at diagnosis (HR 0.17 [0.03-0.95], P = 0.043) were detected as protective factors for patients OS. Whereas for PFS, NAC duration (HR 0.12 [0.02-0.67], P = 0.015) was the only protective factor confirmed, with tumor differentiation at diagnosis exhibiting marginal significance (HR 0.21 [0.04-1.09], P = 0.063).

Conclusions: Patients with LAGC who achieved a pCR displayed favorable long-term survival outcome, especially those with adequate cycles (≥ 3) of NAC. Besides, poor differentiation at diagnosis might also predict the better OS when pCR achieved.