Detection of HER2 status of circulating tumor cells and disseminated tumor cells using a microfluidic platform (cell enrichment and extraction technology [CEE]).

613 Background: Evaluation of HER2 status of circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) can provide valuable information to make therapy changes. We report here the utility of a microfluidic platform for evaluation of HER2 gene amplification in CTCs and DTCs by fluorescent in situ hybridization (FISH). Methods: Blood (10ml) and BM (1–2ml) were collected from patients with operable breast cancer. Mononuclear cells were recovered, incubated with a mixture of 10 primary capture antibodies(Abs), introduced into CEE microchannels ( Biocept, Inc,San Diego), stained with fluorescent cytokeratin (CK) and CD45 Abs and then processed for FISH using probes specific to centromere 8 (spectrum aqua), 17 (spectrum green) and HER2 (spectrum orange). The ratio of HER2:CEP17 >2.2 in any CD45 negative cell was regarded as positive for HER2 gene amplification. Results: Blood and BM from 50 patients with T1N0(26),T1N1(5),T2N0(6),T2N1 (3),T2N3(3),T3N0 (2),T3N1(1),T4N1(2),T4N3(2) with 7 HER2+ and 43 HER2...