Prediction of post-nephroureterectomy renal function in non-dialysis upper tract urothelial carcinoma using machine learning with PyCaret and SHAP explanations

Renal function after radical nephroureterectomy (RNU) in patients with advanced upper tract urothelial carcinoma (UTUC) is an indicator of eligibility for postoperative chemotherapy. The present study aimed to utilize machine learning for predicting renal function status after RNU and to investigate the contribution of several features to this prediction. The present retrospective study included 764 medical records of patients with non-metastatic UTUC who received RNU from 2008 to 2022. The records were divided into training (n=534) and testing (n=230) datasets. Several demographic and clinicopathological parameters were collected for analysis. PyCaret was utilized for data processing, model establishment and comparison, while SHapley Additive exPlanations values were adopted to assess the contribution of each variable to the predictive performance of the model. The results demonstrated that the Random Forest Regressor model had improved accuracy in predicting postoperative renal function compared with other algorithms. In both the estimated glomerular filtration rate (eGFR) and chronic kidney disease outcome, preoperative renal function had the most marked contribution to postoperative renal function. Additionally, the Charlson Comorbidity Index (CCI), body mass index (BMI) and tumor size were highly associated with renal function after RNU, and hydronephrosis was another main factor for predicting postoperative eGFR. The retrospective design was a limitation of the present study. The results demonstrated that important predictors, including preoperative eGFR, tumor size, BMI, CCI and hydronephrosis, were associated with postoperative renal function. To conclude, using a machine learning prediction model may be used in the future to determine appropriate therapeutic strategies and inform the timing of perioperative systemic chemotherapy, in particular perioperative systemic chemotherapy, for advanced UTUC.