Pathologic response rates from neoadjuvant chemotherapy in muscle-invasive transitional cell carcinoma of the bladder.

Abstract

e15181 Background: Neoadjuvant chemotherapy (NC) with MVAC for muscle invasive transitional cell carcinoma (TCC) of the bladder has been shown to improve survival, with pathologic complete response (pCR) serving as a robust predictor of survival benefit. While gemcitabine/cisplatin (GC) is often substituted in the neoadjuvant setting, positive randomized neoadjuvant data are available only for MVAC, and recent retrospective data have noted low pathologic complete response rates with GC. Methods: Data was retrospectively collected on 110 patients with T2-T4Nany TCC of the bladder who underwent radical cystectomy (RC) at the University of Washington Medical Center between September 2003 and July 2009. Information on clinical stage, neoadjuvant chemotherapy, comorbidities and pCR were collected. The prespecified primary endpoint was pCR rates comparing MVAC and GC neoadjuvant groups. Results: Of 110 patients, 43% received NC (total=47: GC=18, MVAC=12, dose dense MVAC=2, gem/carboplatin=7, other=8). Percentage of patients with advanced clinical stage at diagnosis as defined by T3 or greater or node positive was higher in patients administered NC and highest in those administered GC (any NC 43%, GC 72%, MVAC 50%, no NC 22%). pCR rates were significantly improved in patients undergoing NC versus surgery alone (28% vs. 12%, p=.03). No significant difference was noted in pCR rates (pT0) between GC and MVAC subgroups (33% vs. 17%, p=.31). When comparing rates of pCR allowing for residual in situ (pTIS) disease, NC provided superior response rates when compared with surgery alone (49% vs. 15%, p=.0001), and neoadjuvant GC provided superior response rates when compared to MVAC (67% vs. 25%, p=.025). Conclusions: Neoadjuvant chemotherapy for muscle invasive bladder TCC produced significantly increased pCR rates in comparison to surgery alone in patients who underwent RC at our institution. Interestingly, while there was no statistical difference in pathologic pT0 rates in the GC versus MVAC subgroups, when residual pTIS was allowed GC improved response rates over MVAC. These observations are in contrast to prior observations and support the use of GC as an alternative regimen in the neoadjuvant setting.