Which is the optimal management for locally advanced gastric cancer patients with TRG 0 and 1 after R0 resection?

Background: Neoadjuvant chemotherapy (NAC) followed by surgery currently offers promise as a strategy for patients with locally advanced gastric cancer (GC). However, there is limited evidence to guide treatment for TRG 0 and 1 patients with locally advanced GC after R0 resection. This study set out to explore the optimal management for TRG 0 and 1 patients with locally advanced GC after R0 resection. Methods: The retrospective data of 154 TRG 0 and 1 patients with locally advanced GC following R0 resection who were treated between January 2012 and December 2018 were collected and analyzed. The Kaplan-Meier method was used to estimate the survival rate. Multivariate analysis was performed using the Cox proportional hazards model. Results: The median follow-up was 34.1 (range, 6.6-90.9) months. Six patients (3.9%) were lost during follow-up. Of the 27 patients who experienced relapse, 12 died, including 2 patients who died of non-neoplastic causes. The 5-year recurrence-free survival (RFS) and 5-year overall survival (OS) were 71.6% (95% CI: 68.5-79.6) and 82.9% (95% CI: 76.9-86.1) for the whole cohort, respectively. Univariate analysis revealed that patients with carcinoembryonic antigen (CEA) <5.0 ng/ml after NAC (77.7% vs. 20.1%, P<0.001), distal gastrectomy (91.7% vs. 67.5%, P=0.046) had higher 5-year RFS. Meanwhile, combined resection (55.6% vs. 73.1%, P=0.042), major complications (42.7% vs. 80.50%, P<0.001), and lymph node metastasis (ypN+) (52.0% vs. 83.7%, P<0.001) had lower 5-year RFS. The multivariate analysis showed that CEA level after NAC (HR =2.876, 95% CI: 1.051-7.872, P=0.040), major complications (HR =2.432, 95% CI: 1.062-5.567, P=0.035), and lymph node metastasis (ypN+) (HR =3.183, 95% CI: 1.242-8.161, P=0.016) were independent prognostic factors. Conclusions: TRG 0 and 1 patients with local GC after R0 resection following NAC had a good prognosis, especially patients with CEA <5.0 ng/mL after NAC, and those without major complications or lymph node metastasis. Monotherapy or no chemotherapy may offer options for treating TRG 0 and 1 patients without adverse prognostic factors.