A recent study funded by the Medical Research Council published in the journal Nature Communications has shown that a blood test may help predict if a patient with breast cancer is responding to treatment with palbociclib.
Researchers at The Institute of Cancer Research (ICR), London, and The Royal Marsden NHS Foundation Trust, found that the test was able to detect response to the drug within 2-3 weeks; however, they warn that using the test clinically would require replication of the results.
The study included women with oestrogen receptor-positive breast cancer who were participating in a clinical trial for palbociclib. Response to palbociclib could be predicted by comparing the amount of a gene PIK3CA through a blood test performed before treatment and 15 days after initiating treatment.
73 women with PIK3CA mutation received blood tests before and after starting treatment, of which 52 were treated with palbociclib. A small reduction in PIK3CA circulating DNA at 15 days was associated with a median PFS of only 4.1 months, whereas a large reduction in PIK3CA was associated with median PFS of 11.2 months.
Professor Nicholas Turner, Professor of Molecular Oncology at ICR, London, and Consultant Medical Oncologist at The Royal Marsden NHS Foundation Trust, said: "By predicting if a therapy is likely to work, clinicians can adapt treatment strategies by switching patients to alternative therapies from which they are most likely to benefit."
