Preoperative prognostic nomogram (probability table) for renal cell carcinoma based on TNM classification

Abstract

Purpose: Recently several prognostic nomograms have been developed to predict the prognosis of malignant diseases, including renal cell carcinoma. However, to our knowledge a preoperative prognostic nomogram that predicts survival in patients with renal cell carcinoma is not available. We developed a preoperative nomogram based on the TNM classification that predicts cause specific survival in patients with renal cell carcinoma.

Materials and methods: A total of 545 patients with renal cell carcinoma, including metastatic disease, who underwent radical nephrectomy or nephron sparing surgery at our institution were included in the study. Cases were staged according to the 2002 UICC TNM system, 6th edition. T, N and M factors were used as prognostic factors and a Cox proportional hazards regression model was developed to predict cause specific survival. A nomogram to predict cause specific survival was developed by repeating the analysis on 200 bootstrap samples. To validate the nomogram a concordance index was estimated and calibration was also examined by plotting the predictions made by the nomogram.

Results: Overall 1, 3 and 5-year patient survival was 95.2%, 92.0% and 89.9%, respectively. T, N and M factors were significant prognostic factors in the Cox proportional hazards regression model. Using the combined TNM factors we developed a nomogram predicting 1, 3 and 5-year cause specific survival rates. The nomogram had excellent ability to discriminate, as evidenced by a concordance index of 0.81, and it was generally well calibrated.

Conclusions: The preoperative information shown by this nomogram may be important for obtaining informed consent from patients with renal cell carcinoma who have indications for surgery.