Despite differences in the regression coefficients, which ranged from 1.082 to 2.094 for No. 10 LN metastasis, for simplicity, 1 point was assigned for the preoperative T stage and preoperative N stage and 2 points were assigned for the tumor size. The resulting TNS (preoperative T stage, preoperative N stage, and tumor size) scores were obtained for No. 10 LN metastasis, and the patients in the modeling group were divided into three levels according to this scoring system: low risk (0-2 points, because the incidence rates of No. 10 LN metastasis among patients in 0 and 1 points was 0, 0-2 points were classified as low risk level), intermediate risk (3 points) and high risk (4 points). The distribution of patients according to the scoring system was 59.1% low risk; 26.5% intermediate risk; and 14.4% high risk. The incidence rates of No. 10 LN metastasis among patients in the low-, intermediate-, and high-risk categories were 2.8%, 13.9%, and 34.9%, respectively (χ2 = 28.60, P < 0.001). The relative risks of No. 10 LN metastasis in the intermediate- and high-risk groups compared with those of the low-risk group were 5.532 (95 %CI, 1.853-16.518, P = 0.002) and 18.321 (95 %CI, 6.171-54.392, P < 0.001), respectively (Table 5). The 3-year OS for patients in the low-risk category was significantly higher than that for patients in the intermediate- and high-risk groups (81.3% vs. 60.8% vs. 65.1%, P = 0.001) (Figure 2).