Phase-primed chemotherapy to improve chemotherapy efficacy in metastatic breast cancer patients
Systemic chemotherapy is often the treatment of choice for breast cancer (BC). However, the response to chemotherapy is highly heterogeneous and difficult to predict, even for tumors of the same molecular and pathological subtype. We identified menstrual cycle stage as a determinant of chemotherapy efficacy in primary BC. The clinical implications of this finding are very concrete: by simply timing the first chemotherapy treatment to the follicular phase, a better response rate can be achieved. If this simple intervention could also improve chemotherapy response in the metastatic setting, this would provide a much larger group of pre-menopausal women with metastatic BC, with very limited treatment options, a way of improving the chemotherapy response. The aim of this proposal is to explore whether the menstrual cycle stage impacts on chemotherapy response in metastatic BC. Obtaining preliminary data in the metastatic setting will open up many new opportunities to explore phase-priming of chemotherapy, not only in metastatic BC, but also for other (metastatic) cancers in females. With these data, we can speed up clinical validation of our findings and initiate prospective trials in a much larger group of pre-menopausal BC patients with a pressing need for improved and effective therapies.