[905] Impact of Pathology Review and Substage on the Clinical Outcome of pT1 Bladder Cancer

TH Van der Kwast, M Van der Aa, D Kakiashvili, M Jewett, A Zlotta, BW Van Rhijn. University Health Network, Toronto, ON, Canada; Erasmus MC, Rotterdam, Netherlands

Background: The clinical behaviour of pT1 bladder cancers is highly variable. Therefore we wished to evaluate the impact of pathology review and substaging, using a recently described simple substaging method, on the clinical outcome of pT1 bladder cancers at first presentation.
Design: The slides of 155 first diagnosis pT1 bladder tumors from multiple institutions of two countries (the Netherlands, n=69 and Canada, n=86) were reviewed and substaged, separating pT1micro-invasive (pT1m) and pT1extensive-invasive (pT1e) carcinomas, as previously described.¹ All patients initially diagnosed as pT1 were managed conservatively. Grade review was done according to both the WHO 1973 and 2004 classifications systems. Clinical data were collected by chart review and prognostic impact was determined by Kaplan Meier analysis and multivariate analysis.
Results: Mean follow-up was 6.52 years (range 0.8-21.3 yrs), 28 patients were female and mean age was 69 years at first diagnosis. Fifty-two patients (34%) remained recurrence-free. A cystectomy was performed in 31 patients (20%) and pT2 disease was found in 25 of them. Progression to pT2 or metastasis was detected in 44 (28%) patients and 24 patients died of their disease. After review the pT1 carcinomas were sub-staged as follows: 23 pTa, 40 pT1m, 87 pT1e and 5 pT2. Grade review resulted in 71 G2 and 84 G3 lesions according to the 1973 system and 37 low-grade and 118 high-grade lesions according to the 2004 system. Kaplan Meier analysis demonstrated significant differences for pTa, pT1m, pT1e and pT2 carcinomas. Within the reviewed pT1 carcinomas only substage, but not grade or tumour size proved of independent significance in multivariate analyses with progression (P<0.001) and disease-specific survival (P=0.001) as endpoints.
Conclusions: Review pathology is indicated in pT1 bladder cancer. pT1 substage (pT1m and pT1e) is the only prognosticator for progression and disease-specific survival in pT1 bladder cancer. 1. Van der Aa MNM, van Leenders GJLH, Steyerberg EW, van Rhijn BWG, Jbsis AC, Zwarthoff EC, van der Kwast TH. A new system for substaging pT1 papillary bladder cancer: a prognostic evaluation. Hum Pathol 2005;36:981-6.
Category: Genitourinary (including renal tumors)

Tuesday, March 10, 2009 1:00 PM

Poster Session IV # 146, Tuesday Afternoon