Whether adjuvant chemotherapy (AC) has a survival benefit for pathological stage Ⅰ (T1N0 and T2N0) gastric cancer (GC) patients with negative lymph node (N0) remains controversial.

Patients with surgically resected, histologically confirmed pT1N0 and pT2N0 GC between January 2011 and December 2017 at the National Cancer Center, China, were retrospectively reviewed.

A total of 1601 patients who met the inclusion criteria were identified. Independent risk factors for reduced overall survival (OS) identified in the Cox regression analysis were male sex (hazard ratio [HR] 1.454, 95% confidence interval [CI] 1.127–1.876), age ≥ 65 years (HR 1.367; 95% CI 1.071–1.744 ), T2 stage (HR 1.283; 95% CI 1.005−1.638), tumor size > 3 cm (HR 1.704; 95% CI 1.346−2.158), examined lymph nodes (EN) ≤ 15 (HR 1.327; 95% CI 1.058–1.664), and non-signet ring cell carcinoma (Non-SRCC) (HR 1.639; 95% CI 1.123–2.392). While only T2 stage (HR 1.410; 95% CI 1.026−1.936), tumor size > 3 cm (HR 1.755; 95% CI 1.285−2.397), examined lymph nodes (EN) ≤ 15 (HR 1.489; 95% CI 1.101–2.015) were independent risk factors for cause-specific survival (CSS). We divided patients with pT2N0 into four sub-categories according to two significant prognostic factors (size and EN) and found that only patient in group 3 (EN ≤ 15, size >3 cm) with improved CSS benefit from AC (p = 0.049). More significant CSS benefit from AC was identified in Non-SRCC patients within group 3 (p = 0.034).

An additional survival benefit related to AC is expected for selected pT2N0 patients. Non-SRCC patients with EN ≤ 15 and tumor size >3 cm may be particularly appropriate candidates for AC.