For many women diagnosed with breast cancer, chemotherapy is one of the most daunting parts of treatment.
It can be lifesaving but it also brings significant side effects, including fatigue, nausea, hair loss, a weakened immune system and fertility issues.
Now, a major international clinical trial has found some women with breast cancer could safely avoid chemotherapy, thanks to a genomic test that helps doctors better understand who benefits from the treatment.
A more targeted approach
Breast cancer treatment often involves surgery to remove the tumour, followed by chemotherapy to reduce the risk of the cancer coming back.
But the OPTIMA trial, led by researchers at University College London, suggests some patients can be spared chemotherapy without compromising their outcomes.
The trial followed more than 4,400 patients around the world, including 263 patients from Australia and New Zealand. All participants were aged 40 and over and had hormone receptor-positive breast cancer, the most common form of the disease.
Researchers used a genomic test called Prosigna, which looks at the activity of genes involved in breast cancer growth and helps calculate a patient’s risk of recurrence.
Some patients received standard treatment, with chemotherapy followed by hormone therapy. Others had their tumour tested first. Those with a high Prosigna score received chemotherapy and hormone therapy, while those with a low score were treated with hormone therapy alone. Radiotherapy and other usual treatments were still given where needed.
Safely avoiding chemotherapy
Researchers found that around two-thirds of patients whose tumours had a low Prosigna score were treated safely with hormone-blocking therapy alone.
Their five-year survival rate was 93.7 per cent, compared with 94.9 per cent among patients who received chemotherapy as part of their care.
For patients with low test scores, chemotherapy offered little or no extra benefit.
Australian Study Chair Associate Professor Belinda Kiely said: “OPTIMA addresses a long-standing challenge in breast cancer care: identifying who benefits from chemotherapy and who does not.”
“These findings show that chemotherapy offers little or no additional benefit for people with low Prosigna scores, meaning a substantial number of patients could safely avoid it and its physical and emotional side effects without compromising their outcomes.
“The results mark a significant step toward more personalised treatment.”
It is not yet known whether the findings apply to people under the age of 40. The next phase of OPTIMA is expected to provide more information about how the test applies to premenopausal women.
For now, the research marks an important step towards more tailored breast cancer treatment – helping patients receive the care they need, while avoiding treatment they do not.
