Capecitabine is an important treatment option for women with advanced breast cancer. Unfortunately, 5-10% of patients, will suffer from potentially fatal side-effects including blistering, severe pain in the hands and feet, and diarrhoea. Side effects occur due to the absence of a substance in the liver, which usually removes capecitabine from the bloodstream.
This same substance removes thymine, a component of DNA, from the bloodstream also – an important fact that can be used to determine the levels of enzyme that a patient has in their liver and, therefore, whether they are likely to suffer from side-effects from capacitabine.
Associate Professor Helsby and her team give patients additional thymine and then measure how much is removed from the bloodstream. This information allows them to identify patients who would be at risk of side-effects and provide them with alternative treatment options.
“Capecitabine is a very valuable treatment, but it isn't right for all patients,” says Associate Professor Helsby. ''If we can determine which patients will suffer side-effects before they take the drug, we'll be able to spare them a huge amount of discomfort, and prescribe them a treatment that they'll tolerate.''