DR-046 CPCT-02 Breast NAVIGATOR: Non-invasive monitoring of breast cancer therapy using cell-free tumor DNA in blood

Resistance to therapy is one of the main challenges in treatment of metastatic breast cancer. We know that treatment resistance is often driven by changes in the genetic material of the tumor. Tumor DNA is, to some extend, detectable in the blood of cancer patients as circulating tumor DNA (ctDNA). Analysis of ctDNA might enable monitoring of response to anti cancer therapy over time and at low impact. The aim of this study is therefore to identify aberrations in ctDNA related to treatment outcome and to see whether those aberrations change during treatment. Furthermore, we aim to explore to what extend ctDNA represents the genomic landscape of metastastic breast cancer. Therefore, our findings in ctDNA and in metastatic tumor tissue will be compared in a subset of patients.

John Martens Erasmus MC the Netherlands