Heterogeneous estrogen receptor expression in circulating tumor cells suggests diverse mechanisms of fulvestrant resistance

Fulvestrant is a dose dependent selective estrogen receptor (ER) down-regulator (SERD) used in ER-positive metastatic breast cancer (MBC). Nearly all patients develop resistance. We performed molecular analysis of circulating tumor cells (CTC) to gain insight into fulvestrant resistance.Preclinical studies were performed with cultured breast cancer cells spiked into human blood and analyzed on the CellSearch® system. Clinical data are limited to a subset of patients with ER-positive MBC from a previously reported pilot trial whose disease was progressing on fulvestrant (N=7) or aromatase inhibitors (AIs) (N=10).

Source: Molecular Oncology - April 28, 2016 Category: Cancer & Oncology Authors: Costanza Paoletti, Jose M. Larios, Maria C. Muñiz, Kimberly Aung, Emily M. Cannell, Elizabeth P. Darga, Kelley M. Kidwell, Dafydd G. Thomas, Nahomi Tokudome, Martha E. Brown, Mark C. Connelly, David A. Chianese, Anne F. Schott, N. Lynn Henry, James M. Ra Source Type: research