Test predicts cancer return chances

The scientists are from the Breakthrough Breast Cancer Research Centre at The Institute of Cancer Research (ICR) and Queen Mary, University of London. They believe this approach, which could be rolled out within the next one to two years, will help doctors identify high risk patients early on allowing for more targeted treatment and avoiding unnecessary chemotherapy for those at lower risk of recurrence.

The findings, published in the Journal of Clinical Oncology, show that measuring the levels of four proteins - ER, PR, HER2 and Ki67 - is just as effective at predicting high and low risk women as the successful but expensive American Oncotype DX®.  The Oncotype test is only available in one laboratory in the United States and costs approximately £2,500 per patient.  In contrast, the new IHC4 test uses two assays that are routinely analysed at the point of diagnosis in the UK (ER and HER2) and two more (PR and Ki67) that are simple and could be easily performed throughout the country using equipment already available in many laboratories.

Study co-leader Professor Mitch Dowsett, from the Breakthrough Breast Cancer Research Centre at the ICR and The Royal Marsden Hospital, said:

“This is excellent news for women who are diagnosed with ER positive breast cancer. It is a major step towards more personalized and targeted treatment of breast cancer, which will mean that women can avoid unnecessary chemotherapy and its toxic side effects.

“Oncotype DX®is a valuable method of identifying patients whose breast cancer could re-occur but most cancer specialists do no have the money available to use it.  IHC4 could make this information available to them without adding significantly to NHS costs and in fact could help reduce spending by cutting unnecessary chemotherapy treatment.”

Professor Dowsett’s team used a pool of over 1,800 samples collected from the TransATAC clinical trial to compare the IHC4 method with the established Oncotype DX® technology. Once they had concluded that the IHC4 test was just as effective in identifying high and low risk women they rolled out the comparison to another group of patients in Nottingham and reproduced the same findings.

Study co-leader Professor Jack Cuzick, from Queen Mary, University of London, said:

“Although tests such as Oncotype DX® have been developed and are informative, they can be expensive and involve sending samples to the US, which limit their use in many parts of the world.  Clinicians may therefore have to make therapy decisions based on limited prognostic information.

"The new IHC4 technique bypasses any barriers due to the ease with which the test can be implemented and it has the potential to be a key component in the battle against breast cancer.”

This research was funded by Breakthrough Breast Cancer through the Mary-Jean Mitchell Green Foundation, Cancer Research UK and The Royal Marsden NIHR Biomedical Research Centre.