A simple screening score to predict diabetes in cancer patients: A Korean nationwide population-based cohort study

Many cancer patients develop diabetes, which may result in reduction of chemotherapy effectiveness and increased infection risk and cardiovascular mortality. Diabetes may also increase the risks of chemotherapy-related toxicity and post-operative mortality, or represent an obstacle to optimal cancer treatment. However, the clinical predictors of diabetes in cancer patients remain largely unknown. Therefore, the aim of our study was to evaluate the risk factors for developing diabetes and construct a nomogram to predict diabetes in cancer patients. We investigated patients from a national sample cohort obtained from the Korea National Health Insurance Service (KNHIS), which included 2% of the Korean population. Patients who had undergone routine medical evaluation by the KNHIS between 2004 and 2008 and been hospitalized due to cancer (ICD-10 codes C00–97) during the past 3 years were included. After excluding patients with type 2 diabetes and missing data, 10,899 patients were enrolled and followed-up until 2013. A total of 7630 (70%) patients were assigned as the training cohort and used to construct the nomogram which was based on a multivariable logistic regression model. The remaining patients (n = 3269) were used as the validation cohort. The incidence rate of diabetes was 12.1 per 1000 person-years over a mean follow-up of 6.6 ± 1.8 years. Significant risk factors for developing diabetes were age, sex, obesity, fasting plasma glucose, hypertension, and hypercholesterolmia. A nomogram was constructed using these variables and internally validated. The area under the curve was 0.70 (95% confidence interval, .666-.730, P < .0001) and the calibration plot showed agreement between the actual and nomogram-predicted diabetes probabilities. The nomogram developed in this study is easy to use and convenient for identifying cancer patients at high-risk for type 2 diabetes, enabling early type 2 diabetes screening and management.