Circulating Tumor Cells (Ctc) As Potential Biomarkers In Neoadjuvant Chemotherapy Of Muscle Invasive Bladder Cancer (Mibc).

330 Background: Biomarkers to assess early response to cisplatin based neoadjuvant chemotherapy (NAC) in MIBC is a clinical need. We hypothesized that CTC enumeration and genomic profiling using a novel microfluidic immunomagnetic assay IsoFlux (Fluxion Biosciences Inc., CA) could provide novel biomarkers in individual patients during NAC. Methods: Peripheral blood was drawn at baseline and after one cycle (3-4 weeks) of NAC in patients (pts) with locally advanced resectable bladder cancer in an IRB approved prospective study at the University of Michigan. CTCs were enumerated by the CellSearch and IsoFlux assays in parallel and by IsoFlux in duplicate samples. We correlated CTC numbers with pStage at cystectomy, a known prognostic variable for survival. We assessed gene expression by RT-PCR and gene mutational status by Ion Torrent sequencing on CTCs. Results: We analyzed 21 pts with localized muscle invasive bladder cancer (cT2-T4aNx). Mean age was 65 yrs with 84% male. Clinical stage was 71% cT2N0, 14%...