Does renal capsular invasion have any prognostic value in localized renal cell carcinoma?

We evaluated the impact of renal capsular invasion without perirenal fat invasion in the outcome of patients with localized renal cell cancer treated surgically.

We retrospectively reviewed the records of 249 consecutive patients with localized renal cell cancer (pT1-pT2N0M0) who underwent partial or radical nephrectomy between 1995 and 2007. Pathological staging was done according to the 2002 TNM staging system. Association of clinical and pathological parameters with capsular invasion was determined using the chi-square test. Kaplan-Meier estimations of disease specific survival were generated according to capsular invasion and the log rank test was used to compare survival according to the variable.

Renal capsular invasion was detected in 79 of the 249 patients (31.7%). Of the patients 19 of 96 (19.8%) with pT1a, 26 of 87 (29.9%) with pT1b and 34 of 66 (51.1%) with pT2 had renal capsular invasion. Tumor diameter and high grade were associated with renal capsular invasion (p <0.05). Mean followup was 40.7 months. Five-year disease specific survival in patients with and without capsular invasion was 92.7% and 90.4%, respectively (p >0.05). In pT1a, pT1b and pT2 cases differences in Kaplan-Meier estimations according to renal capsular invasion were statistically insignificant (p >0.05). On multivariate analysis renal capsular invasion was not detected as an independent prognostic factor for disease specific survival (HR 0.6582, p = 0.5373).

Tumor diameter and high grade were associated with renal capsular invasion in stage pT1-2 renal cell cancer. However, capsular invasion did not have any independent impact on patient survival.