Prognostic relevance of capsular involvement and collecting system invasion in stage I and II renal cell carcinoma.
OBJECTIVE
To define the prognostic relevance of capsular involvement (invasion with no penetration) and collecting-system invasion in patients with stage I (pT1N0M0) and stage II (pT2N0M0) renal cell carcinoma (RCC), by evaluating the outcome of patients treated with nephrectomy.


METHODS
In all, 519 patients from a kidney cancer database treated with nephrectomy for stage I and II RCC between 1985 and 2005 were assessed retrospectively. The primary endpoint was recurrence-free survival time. The prognostic relevance of capsular involvement and collecting-system invasion were examined using univariate and multivariate survival analysis.


RESULTS
Capsular involvement and collecting-system invasion were evident in 112 (21.6%) and 39 (7.5%) patients, respectively. Capsular involvement was associated with higher Fuhrman grades and larger tumours. The incidence of collecting-system invasion was higher in patients with microvascular invasion. The median follow-up was 49 months. In univariate analysis, patients with capsular involvement and collecting-system invasion had a worse prognosis than patients without (P = 0.007 and <0.001, respectively). In multivariate analysis, capsular involvement (hazard ratio 1.84, P = 0.036) and collecting-system invasion (3.78, P < 0.001) were independent prognostic factors of recurrence-free survival. Interestingly, there was no survival difference between patients with capsular involvement in stage I/II and patients with invasion of perinephric tissue (pT3aN0M0).


CONCLUSIONS
These findings suggest that capsular involvement and collecting-system invasion are poor prognostic findings in stage I and II RCC. They should both be considered when planning the follow-up. A revised pT3a stage including patients with capsular involvement could improve its prognostic validity.
Klatte
Tobias
T
Department of Urology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
Chung
Jinsoo
J
Leppert
John T
JT
Lam
John S
JS
Pantuck
Allan J
AJ
Figlin
Robert A
RA
Belldegrun
Arie S
AS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002292:Carcinoma, Renal Cell / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D007685:Kidney Tubules, Collecting / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D009392:Nephrectomy / Q000592:standards*; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis