ABSTRACT
Purpose: This multiinstitutional study was to investigate the accuracy of the Kattan nomograms for the prediction of recurrence after definitive surgery for renal cell carcinoma (RCC) in Korean patients and develop a nomogram revised to complement the shortcomings. Materials and Methods: Clinical and pathological data of 1,866 patients with RCC who had been followed for at least 2 years after surgery in each participating institutes were reviewed as well as evidence of disease recurrence, defined to include local recurrence and distant metastasis. Accuracy of the Kattan nomograms' predictability in tumors 7cm or less was tested by calculating the area under the receiver-operating characteristics curve (AUC) and actuarial recurrence-free survival by Kaplan- Meier method. We used the Cox proportional hazard analysis to identify significant variables and develop prediction nomogram, and internally validated by bootstrapping method. Mean follow-up was 56.5 months (24-184). Results: Recurrence occurred in 12.5% of the patients and correlated with the pathological stage, with 4.3%, 7.9%, 15.0%, 22.6%, 38.4%, 58.3% for stages T1a, T1b, T2, T3a, T3b/c and T4, respectively (p<0.001). The AUC of the Kattan nomograms was 0.276. Factors significantly predictive of recurrence were T stage (p<0.0001), presentation (p=0.006), preoperative hemoglobin (p=0.023) and gender (p=0.032). Actuarial 60-month recurrence- free survival was 87.9% and using the prognostic factors, nomogram predicting 60-month recurrence-free survival was constructed. Conclusions: Korean nomogram complementing the preexisting nomograms for the prediction of recurrence-free survival after definitive surgery for RCC has been constructed, which may be useful in patient prognostication, counseling and follow-up planning.