A trial sponsored by Velindre University NHS Trust and led by Velindre Cancer Centre and Cardiff University has found a potential new way of predicting the outcome of breast cancer patients who are taking a drug called fulvestrant. The findings will be presented at the prestigious international European Society of Medical Oncology conference (ESMO) on 18 September, which will be held online this year.
Cancer researchers are always striving to improve the way treatments are delivered to patients. Fulvestrant, developed by AstraZeneca, has been a successful drug in the treatment of breast cancer, but this research has identified a biomarker which appears to pick out patients who gain most benefit from the drug.
Discoveries like this mean that, potentially, doctors can more accurately pick treatments that are more likely to work in an individual patient. This could not only saves patients from undergoing unnecessary treatment, but it could also save the NHS money.
The trial, which was endorsed by Cancer Research UK, looked at patients with advanced Oestrogen Receptor positive breast cancer that has spread around the body, where hormone therapy is often the best treatment. There are many different ways in which breast cancer cells become resistant to hormone treatments, and one is thought to be the activation of a ‘signalling’ pathway in the cells involving a protein called RET. Studying the level of RET protein expression in patients on this trial led to this finding. The trial involved 165 patients from 19 different hospitals across the UK and the data was coordinated and analysed by the Centre for Trials Research at Cardiff University. All patients took fulvestrant, and the trial assessed whether adding a new drug called vandetanib could improve outcomes further. The research team found no evidence that patients receiving vandetanib gained additional benefit. However, the trial has shown that patients on fulvestrant treatment whose cancers have higher levels of the RET protein do much better. In fact, in this trial their cancer is controlled for over twice as long as those who have low RET levels and this is highly statistically significant.
Dr Rob Jones of Cardiff University and Velindre University NHS Trust and Mark Beresford of Bath University led on the study. Rob said, “This finding was actually quite a surprise as previous laboratory work has indicated activated RET can lead to resistance to hormone therapy. However, our data, which looked at cancer tissue samples from patients in the trial, clearly indicated that patients with high RET levels in their cancers received much greater benefits, which is likely to be as a result of fulvestrant treatment. I am delighted that we have been invited to present these findings at ESMO. Velindre Cancer Centre, together with the Centre for Trials Research at Cardiff University, have been at the forefront of delivering new clinical trials for cancer patients and this is a real recognition of the value of the work we do here in Wales.”
Mark added, “Only one in four cancer trials produce positive results, and although ours didn’t show the results we were looking for, I’m delighted that these findings could go on to improve treatment for patients.”
As this finding was largely unexpected it will be important to confirm this with further research, but it could lead to an additional tool in making informed treatment choices for breast cancer patients.