Purpose: T stage stratification of organ confined renal tumors is based only on tumor size. Currently T1a and T1b are defined as tumors less or greater than 4 cm. However, to our knowledge the validity of this stratification has not been determined. We determined whether symptoms could add additional prognostic information when integrated with tumor size into the TNM classification.
Materials and methods: Patients with T1-T2N0M0 renal tumors at 6 academic centers in Europe and the United States were included in this study. T stage was defined according to the 2002 TNM classification. Age, gender, T stage, tumor size, symptoms at presentation, Fuhrman grade and cancer specific survival were determined in all cases. Survival estimates were compared using the Kaplan-Meier method and multivariate analysis of the data were performed with the Cox model.
Results: A total of 1,771 patients with pT1-T2N0M0 renal tumors were included in this study. There were 1,148 males and 623 females. Mean age was 59.6 years. Median tumor size was 5 cm. Of the tumors 781 (44.1%), 616 (34.8%) and 374 (21.1%) were stages T1a, T1b and T2, respectively. In 825 patients (46.6%) symptoms were related to renal cancer. T stage and symptoms strongly correlated, in that 67%, 51% and 29% of patients with T1a, T1b and T2 tumors, respectively, were asymptomatic. Symptoms increased the risk of cause specific death for each T stage level. On multivariate analysis Fuhrman grade (HR 1.46), T stage (HR 1.81) and symptoms (HR 2.98) were independent predictors of survival. Based on these results 4 groups resulting from combinations of 2002 TNM stage and symptoms with significantly different risks of death were defined, namely 1) T1a-4 cm or less without symptoms, 2) T1b-4 cm or less with symptoms and greater than 4 cm without symptoms, 3) T2a-greater than 4 cm and 7 cm or less with symptoms, and 4) T2b-greater than 7 cm with symptoms
Conclusions: In this study we noted that a system combining tumor size and symptoms can accurately stratify patients for predicting survival in those with organ confined renal tumors. Our data support the idea that symptoms should be integrated in further modifications of the TNM system.