Scientists from MRC discovered a blood test to detect whether a patient was reacting to the breast cancer drug palbociclib.

At present, breast cancer patients need to wait for nearly two to three months to find out via a scan whether palbociclib is working. This new test could detect the circulating tumor DNA which enters the bloodstream. By measuring and comparing PIK3CA levels in a blood test before and 15 post palbociclib therapy, one could predict the effectiveness of the drug.

Professor Nicholas Turneropens, senior author and Professor of Molecular Oncology at The Institute of Cancer Research, London, and Consultant Medical Oncologist at The Royal Marsden NHS Foundation Trust, said “Having an early indication of how likely a treatment is to work might allow us to adapt treatment – switching some patients to an alternative drug that is more likely to benefit them.”

Dr. Nathan Richardson, Head of Molecular and Cellular Medicine at the MRC, also stated “It is exciting to see that using advances in diagnostic techniques, such as genetic tests for circulating tumor DNA, we may be able to more accurately define groups of patients and help us deliver the right treatment to the right patient sooner. This study provides early evidence that might help us understand sooner when a drug is successfully treating breast cancer, and if not, it can be discontinued and better approaches pursued.”