Prognostic value of capsular invasion for localized clear-cell renal cell carcinoma
Hyuk-Jin Cho1, Su Jin Kim, U-Syn Ha
1Department of Urology, Kangnam St. Mary's Hospital, The Catholic University of Korea, College of Medicine, Seoul, Korea.
Background:
The impact of capsular invasion on the survival of patients undergoing surgery for renal cell carcinoma (RCC) has attracted little attention in the literature and remains controversial.
Objectives:
To evaluate the value of capsular invasion, without perirenal fat invasion, on the prognosis of patients with localized clear-cell RCC.
Design, Setting, And Participants:
Between 1984 and 2007, we retrospectively reviewed the records of 317 consecutive patients with localized clear-cell RCC (pT1-T2N0M0) who underwent radical nephrectomy or nephron-sparing surgery at our institution. Overall, 299 patients were eligible for the study. We analyzed clinical (presentation and body mass index [BMI]) and pathologic (tumor size, Fuhrman nuclear grade, collecting system invasion, microvascular invasion, and capsular involvement) parameters.
Measurements:
Recurrence-free survival (RFS) and cancer-specific survival (CSS) were investigated using the Kaplan-Meier method, and the Cox regression model was used to determine the significant prognostic factors based on multivariate analysis.
Results And Limitations:
Renal capsular invasion was observed in 106 of 299 patients (35.5%). Capsular invasion had a statistically significant association with age, symptomatic presentation, tumor diameter, pathologic stage, collecting system invasion, and microvascular invasion. The mean follow-up was 60.5 mo (range: 1-249). The 5-yr RFS and CSS rates for tumors with capsular invasion were significantly lower compared with rates for tumors without invasion (77.7% vs 92.3% and 85.5% vs 95.7%, respectively; p=0.0004). Multivariate analysis showed that BMI (hazard ratio [HR]=0.19), stage (HR=2.45), and capsular invasion (HR=3.36) were independent prognostic factors of disease recurrence. With respect to CSS, BMI (HR=0.20), tumor size (HR=1.13), and capsular invasion (HR=4.03) were the factors related to death. Nevertheless, we recognize that these findings may be limited by the study's retrospective, single-institution design.
Conclusions:
Our findings suggest that capsular invasion is associated with poor survival in patients with localized clear-cell RCC.