| Summary: | In metastatic breast cancer (MBC) the molecular characterization of circulating tumor cells (CTCs) provides a unique tool to understand metastasis-biology and therapy-resistance. We evaluated the prognostic significance of gene expression in EpCAM<sup>(+)</sup> CTCs in 46 MBC patients based on a long follow-up. We selected a panel consisting of stem cell markers (<i>CD24</i>, <i>CD44</i>, <i>ALDH1</i>), the mesenchymal marker <i>TWIST1</i>, receptors (<i>ESR1</i>, <i>PGR</i>, <i>HER2</i>, <i>EGFR</i>) and the epithelial marker <i>CK-19</i>. Singleplex RT-qPCR was used for <i>TWIST1</i> and <i>CK-19</i> and multiplex RT-qPCR for stem cell markers and receptors. A group of 19 healthy donors (HD) was used as control. Univariate (<i>p</i> = 0.001) and multivariate analysis (<i>p</i> = 0.002) revealed the prognostic value of combined gene expression of <i>CK-19</i>(+), <i>CD44<sup>high</sup>/CD24<sup>low</sup></i>, <i>ALDH1<sup>high</sup>/CD24<sup>low</sup></i> and <i>HER2</i> over-expression for overall survival (OS). The Kaplan–Meier estimates of OS were significantly different in patients positive for <i>CK-19</i> (<i>p</i> = 0.028), <i>CD44<sup>high</sup>/CD24<sup>low</sup></i> (<i>p</i> = 0.002), <i>ALDH1<sup>high</sup>/CD24<sup>low</sup></i> (<i>p</i> = 0.007) and <i>HER2</i>-positive (<i>p</i> = 0.022). Our results indicate that combined gene expression analysis in EpCAM<sup>(+)</sup> CTCs provides prognostic information in MBC.
|
|---|
