title: Prognostic value of capsular invasion for localized clear-cell renal cell carcinoma.
abstract: 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.
  
  
  OBJECTIVE
  To evaluate the value of capsular invasion, without perirenal fat invasion, on the prognosis of patients with localized clear-cell RCC.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Urology, Kangnam St. Mary's Hospital, The Catholic University of Korea, College of Medicine, Seoul, Korea.
authors.forename: Hyuk-Jin
authors.initials: HJ
authors.lastname: Cho
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: U-Syn
authors.initials: US
authors.lastname: Ha
authors.forename: Sung-Hoo
authors.initials: SH
authors.lastname: Hong
authors.forename: Joon Chul
authors.initials: JC
authors.lastname: Kim
authors.forename: Yeong-Jin
authors.initials: YJ
authors.lastname: Choi
authors.forename: Tae-Kon
authors.initials: TK
authors.lastname: Hwang
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D005205:Fascia / Q000473:pathology; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D009367:Neoplasm Staging / Q000401:mortality; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models