A prognostic model for oral squamous cell carcinoma patients with type 2 diabetes mellitus

Objective: To build a prognostic model for oral squamous cell carcinoma patients with type 2 diabetes mellitus. Design: Oral squamous cell carcinoma patients with type 2 diabetes mellitus in Xiangya Hospital were studied. Patients during January 2011 to January 2015 were included in training set (n = 146), and those during January 2017 to December 2020 were included in test set (n = 81). Univariate and multivariate Cox regressions were used to screen independent prognostic variables. Nomogram was used to show the model. C-index, internal bootstrap resampling and external validation were used to evaluate the model. Results: Six independent prognostic factors (T stage, N stage, pathological grade, metformin use, sulfonylureas use, and fasting blood glucose) were screened from training set. Based on the six variables, nomogram was constructed to predict the prognosis of oral squamous cell carcinoma patients with type 2 diabetes mellitus. Cindex value was 0.728, and result of internal bootstrap resampling showed better prediction efficiency for oneyear survival. All patients were divided into two groups according to total points calculated based on the model. Group with low total points experienced better survival than that with high total points both in training set and test set. Conclusions: The model provides a relatively accurate method to predict the prognosis of oral squamous cell carcinoma patients with type 2 diabetes mellitus.