Patients with distant metastases from renal cell carcinoma can be accurately identified: external validation of a new nomogram

OBJECTIVE To identify clinical variables that can accurately predict the presence of distant metastases in patients with renal cell carcinoma (RCC). PATIENTS AND METHODS Age, symptom classification, tumour size and the prevalence of distant metastases at diagnosis before nephrectomy were available for 5376 patients with pathologically confirmed RCC. The data of 2660 (49.5%) patients from 11 centres were used to develop a multivariable logistic regression model-based nomogram predicting the individual probability of distant metastases. The remaining data from 2716 (50.5%) patients from three institutions were used for external validation. RESULTS In the development cohort, 269/2660 (10.1%) had distant metastases, vs 285/2716 (10.5%) in the external validation cohort. Symptom classification and tumour size were independent predictors of distant metastases in the development cohort; age was not an independent predictor. A nomogram based on symptom classification and tumour size was 85.2% accurate in predicting the individual probability of distant metastases in the external validation cohort. CONCLUSION Although distant metastases might be easily identifiable in some patients, their diagnosis might be a challenge in others. The current nomogram provides a simple, user-friendly and, most importantly, an accurate tool aimed at predicting the probability of distant metastases in patients with RCC.