Phase II study of neoadjuvant dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (ddMVAC) chemotherapy in patients with muscle-invasive urothelial cancer (MI-UC): Pathologic and radiologic response, serum tumor markers, and DNA excision repair pathway biomarkers in relation to disease-free survival (DFS).

4530 Background: Neoadjuvant (NA) ddMVAC in patients (pts) with MI-UC is associated with significant pathologic response (PaR) and radiologic response (RaR). We examined the frequency of PaR and RaR as well as the level of serum and tissue biomarkers in correlation with DFS. Methods: Pts treated on phase II prospective study of NA ddMVAC (4 cycles) in MI-UC were evaluated for RaR (at least >50% decrease in the primary tumor and nodes after chemotherapy, with delayed enhancement of residual disease) and PaR (p 0.1 (positive). Fisher’s Exact test was used to evaluate association with response. Post-surgery DFS was estimated by the Kaplan-Meier method and compared between response and biomarker groups using the logrank test. Results: Of 39 pts (cT2:4...