While previous studies found that the survival benefits were gained from chemoradiotherapy (CRT) inpatients of intestinal-type gastric cancer with lymph node metastasis, our findings highlight a distinct subgroup—patients with a lymph node ratio (LNR) ≤ 0.5 and HER2-negative tumors—for whom adjuvant chemoradiation may offer significant improvements in disease-free survival (DFS). Here, ERBB2 is linked to gastric cancer.