The 299 patients in the model development group included 228 males (76.5%) and 70 females (23.5%) with a mean age of 60.44 ± 10.29 years. The average body mass index (BMI) of the patients was 22.15 ± 2.71 kg/m2. The preoperative clinicopathological characteristics of the patients between the modeling and validation groups were compared, and the differences showed no statistical significance (Table 1).