Re: prognostic relevance of capsular involvement and collecting system invasion in stage I and II renal cell carcinoma

Klatte and coworkers examined the prognostic relevance of capsular involvement with no invasion of the perinephric fat and collecting system invasion in a series of 519 patients with intracapsular renal cell carcinoma (RCC) treated with partial or radical nephrectomy and followed for a median of 49 mo (range: 1-199 mo).Capsular involvement and collecting system invasion were reported in 21.6% and 7.5% of patients, respectively. Capsular involvement was significantly associated with a higher nuclear grade and larger tumors, whereas collecting system invasion was significantly associated only with microvascular invasion. In addition, capsular involvement and collecting system invasion were not associated with each other, but had a significant impact on recurrence-free survival (p = 0.007 and p < 0.001, respectively). Interestingly, patients with capsular involvement had the same recurrence-free survival as patients diagnosed as having pT3a N0 M0 RCC. In multivariate analysis, both capsular involvement and collecting system invasion were independent predictors of recurrence-free survival with a reported risk ratio of 1.84 and 3.78, respectively.