Based on the tumor-related analysis, we included the factors into the binary logistic regression model of TRG and found that small tumor size (odds ratio [OR], 0.50; 95% CI 0.27–0.92; P = 0.025), long-duration of chemotherapy (OR, 0.28; 95% CI 0.14–0.53; P < 0.001), primary tumor at left side (OR, 0.44; 95% CI 0.21–0.92; P = 0.030), and a decline in the CEA level (OR, 0.48; 95% CI 0.24–0.94; P = 0.032) after preoperative chemotherapy were favorable predictors of TRG (Table 4). The gene discussed is CEACAM5; the disease is neoplasm.