Breast cancer: Millions of women with breast cancer may be able to avoid chemotherapy after surgery with the help of a genomic test that identifies which patients are unlikely to benefit from the treatment.
Breast cancer treatment often begins with surgery to remove the tumour. Chemotherapy may then be advised if doctors believe there is a risk of the cancer returning. While chemotherapy can be life-saving for some patients, it can also cause difficult side effects, including hair loss, nausea, fatigue, sleep problems, rashes, early menopause, fertility issues and cognitive changes.
A major international trial has now found that a genomic test can help doctors decide which patients can safely skip chemotherapy and receive hormone therapy alone.
The Optima trial, led by University College London, included more than 4,000 patients with newly diagnosed breast cancer across the UK, Norway, Sweden, Australia, New Zealand and Thailand. The findings are expected to be presented at the American Society of Clinical Oncology annual meeting in Chicago.
The test used in the trial, called Prosigna, studies the activity of 50 genes in tumour tissue. It helps identify the molecular type of the cancer and gives a score that estimates the risk of the disease returning over the next 10 years.
Patients with a high score were given chemotherapy followed by hormone therapy. Those with a low score were treated with hormone therapy alone.
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The results showed very similar outcomes in both groups. Five years after treatment, 95% of patients who received chemotherapy and hormone therapy were alive and free from breast cancer recurrence. Among those who skipped chemotherapy and received hormone therapy alone, the figure was 94%.
Researchers said the findings suggest chemotherapy may offer little or no added benefit for many patients with low test scores.
Prof Rob Stein, the trial’s chief investigator and professor of breast oncology at UCL, said the study addresses a long-standing question in breast cancer care: who truly needs chemotherapy and who does not. He said the results mark an important step towards more personalised treatment based on tumour biology, rather than relying only on traditional clinical features.
The trial focused on patients aged 40 and above with hormone-positive breast cancer, the most common type of breast cancer worldwide. Some men were also included in the study, but researchers said the number was too small to draw firm conclusions for male patients.
Experts say the findings could influence future treatment guidelines and reduce unnecessary chemotherapy for many patients, while still protecting cancer outcomes.
For patients, the potential impact is significant: fewer side effects, less emotional and physical strain, and treatment decisions guided more closely by the biology of their cancer.