399P - Detection of Her2 Status of Circulating Tumor Cells in Patients with Metastatic Breast Cancer

Abstract

ABSTRACT Aim: To detect the HER2 status of circulating tumor cells (CTCs) in peripheral blood of metastatic breast cancer patients, in order to asses the relationship of HER2 status between primary tumors and corresponding CTCs in metastatic breast cancer patients. Methods: Peripheral blood samples were analyzed in 69 metastatic breast cancer patients. 45 patients had HER2-negative primary tumor and 24 patients had HER2-positive primary tumor. CTCs were detected by quantitative real-time RT-PCR. Results: 37 patients had a positive CTC sample (53.6%) and of these, 13 patients (35.1%) had HER2 + CTCs. We found non-concordant results in 29.7%(11/37) patients of cases: 32% patients(8/25)of HER2-negative primary tumors had HER2-positive CTCs and 25% (3/12)of HER2-positive primary tumors had HER2-negative CTCs. Conclusions: Our study suggests that a proportion of metastatic patients with HER2-negative primary tumors may develop HER2-positive CTCs during disease progression. This research was supported by the National Nature Science Foundation of China (Key Project no. 30570479) Disclosure: X.L. Dong: This research was supported by the National Nature Science Foundation of China (Key Project no. 30570479). All other authors have declared no conflicts of interest.