Study shows varying results for breast cancer recurrence tests

Branded tests used to determine the likelihood of breast cancers returning after treatment vary in accuracy, recent research has shown.

A study conducted by Queen Mary University of London, UK, funded by Cancer Research UK and published in the JAMA Oncology journal, evaluated four tests on tumour samples from 774 women and looked at whether the cancers returned after treatment.

All of the women had the most common form of breast cancer - oestrogen-receptor positive, HER2-negative breast cancer - which was at an early stage and had been treated with hormone therapy.

The findings showed that the Oncotype DX Recurrence Score was the least effective in predicting relapse in women whose breast cancer had not spread to their lymph nodes. Oncotype DX was previously recommended by the National Institute for Health and Care Excellence for use in the UK, but this decision could be reversed under consultation.

Only the Prosigna Risk of Recurrence Score, Breast Cancer Index and EndoPredict tests showed effectiveness in predicting later-stage recurrence five to ten years after diagnosis.

All four tests were useful in projecting recurrence anywhere up to ten years after diagnosis.

Dr Ivana Sestak, lead researcher on the Queen Mary University project, said one of the potential applications of these findings is helping doctors identify the best test for individual patients.

"If a woman is deemed high risk of recurrence by any test, the benefit of chemotherapy is greatest. In contrast, if a woman is deemed low risk then endocrine therapy alone will be sufficient and patients could forego chemotherapy and its side effects," she said.

Dr Sestak also pointed out that being able to accurately assess the risk of breast cancer returning could enable some women to stop endocrine therapy after five years.

"But for those deemed high risk of a late recurrence, continuing their endocrine therapy would be a valuable option," she added.ADNFCR-2094-ID-801844975-ADNFCR