A test that measures gene activity can help tailor treatment for some women with early-stage breast cancer, according to a clinical trial.

Scientists used the Oncotype Dx test to predict how likely hormone receptor-positive breast cancer was to come back after surgery. Hormone therapy alone was as good as a combination of chemotherapy and hormone therapy in women with an intermediate risk of their cancer returning.

This would mean those women can be spared chemotherapy, and its associated side effects, after surgery.

Scientists previously found that women with a low risk of their cancer returning can receive hormone therapy alone. And experts said the latest trial results should quickly change clinical care for those at intermediate risk too.

Professor Arnie Purushotham, senior clinical advisor at Cancer Research UK, said that by grouping patients based on how likely their cancer is to return, the trial shows great potential to ensure treatment is kinder without compromising its effectiveness.

The results from the phase 3 TAILORx study were presented at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, and are published in The New England Journal of Medicine.

Oncotype Dx is a test designed to predict the risk of breast cancer coming back. It looks for a genetic ‘signature’ in a sample of the tumour and gives a score between 0 and 100, which can help to direct treatment decisions.

It’s one of a few branded tests that have been developed for this purpose and is recommended for use in the UK by the NICE. But this decision is being reviewed.

Research has shown that Oncotype Dx and other tests, including Breast Cancer Index and EndoPredict, vary in accuracy, particularly when predicting the long-term risk of someone’s cancer coming back.

 

Scientists found that giving hormone therapy alone was as good as the combination of chemotherapy and hormone therapy in women with the intermediate score. Survival was similar in both groups, with over nine in 10 women still alive nine years after treatment.

“Our study shows that chemotherapy may be avoided in about 70 percent of these women when its use is guided by the test, thus limiting chemotherapy to the 30 percent who we can predict will benefit from it,” said lead researcher Dr Joseph A. Sparano, associate director for clinical research at the Albert Einstein Cancer Center and Montefiore Health System in New York.

The latest results should mean more women can avoid chemotherapy, and its associated side effects, without compromising the effectiveness of their treatment.