In the CTC-MBC trial, CTCs (circulating tumor cells) are enumerated using the FDA-approved CellSearch® system which, in Sweden, is only available at our lab. CTC are then molecularly characterized, with focus on hormone receptors and HER2, using AdnaTest™ and the DropMount technique developed by us.
Over 150 patients scheduled for 1st line systemic therapy for metastatic breast cancer have been included. The inclusion was closed in June 2016. The two molecular tests can determine molecular characteristics of CTCs as a real-time biopsy and potentially be useful in the clinic for tailoring and monitoring of systemic therapy. By serial sampling at predefined time-points, the project maps the evolution of CTCs related to systemic therapy response. One hypothesis is that clinical progression and treatment resistance to hormonal therapy can be explained by the fact that some clones of CTCs have become hormone receptor negative and are no longer sensitive to this therapy. Assuming that the shift in molecular characteristics of these CTCs proceeds clinical progression, this liquid biopsy could identify treatment failure at an earlier time-point enabling change of therapy and thereby an improved course of the disease.