Research suggests some women can safely avoid chemo and its side effects (Image: Getty)
A cutting-edge gene test could help more than 5,000 women with breast cancer avoid unnecessary chemotherapy every year, a major trial has found. Patients whose early-stage breast cancer has spread to nearby lymph nodes are regularly offered chemotherapy after surgery to reduce the risk of the disease returning. But the gruelling drugs can cause serious side effects and some women with the most common, hormone-sensitive form of the disease receive little or no benefit.
The new test, called Prosigna, analyses a tumour sample to measure the activity of genes involved in cancer growth. An international trial led by UCL found that only 2% of patients with a low score would benefit from chemo. Presenting the findings at the world’s largest cancer conference, chief investigator Professor Rob Stein, an expert in breast oncology at the UCL Cancer Institute, said the trial “addresses a long-standing challenge in breast cancer care: identifying who truly benefits from chemotherapy and who does not”.
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He added: “Our findings show that many patients can safely avoid chemotherapy without compromising their outcomes. Many may be spared the physical and emotional burden of chemotherapy and its potential long-term side effects.”
Chemotherapy uses powerful drugs to destroy cancer cells. Those drugs can also affect healthy body tissues where the cells are constantly growing and dividing.
Side effects include fatigue, hair loss, nausea, and changes to blood cell counts, which can increase vulnerability to infections and cause anaemia.
The OPTIMA trial involved more than 4,400 people in the UK, Norway, Sweden, Australia, New Zealand and Thailand.
Patients were aged 40 and over and had hormone-sensitive breast cancer. In most cases, it had spread to their underarm lymph nodes, placing them at higher risk of recurrence.
Usual treatment includes both a course of chemotherapy and hormone tablets taken for five to ten years. Participants were randomly assigned to receive either standard care or to have treatment guided by their score.
The Prosigna genomic test was performed using samples taken from tumours removed during surgery or from needle biopsies. Two-thirds of participants (68%) had a low score.
Five years later, 94.8% of those who received chemotherapy and hormone therapy were alive and free from breast cancer, compared with 93.6% treated with hormone therapy alone.
Chemotherapy is a useful treatment but can have serious side effects (Image: Getty)
Researchers said this very small difference meant the test could be used, and chemotherapy avoided in many cases, without significantly impacting patients’ chances of recurrence.
Their results — presented at the American Association for Clinical Oncology’s annual meeting in Chicago — will be considered by the National Institute for Health and Care Excellence, which will decide whether the NHS should roll out the test.
It was developed by California-based diagnostics company Veracyte and can be run by NHS laboratories with the appropriate equipment.
Researchers estimate more than 5,000 NHS patients a year could avoid chemotherapy. Prof Stein added that using tumour biology to guide decisions “represents a more efficient and evidence-based use of resources”.
Co-chief investigator Professor Iain MacPherson, of the University of Glasgow, said the research “provides robust, practice‑changing evidence that we can safely reduce the use of chemotherapy for many patients with hormone‑sensitive breast cancer”.
He added: “These findings represent a major step forward in delivering more personalised, precise care, ensuring that treatment decisions are driven by what will genuinely improve outcomes for patients, while avoiding unnecessary toxicity. The potential impact for both patients and health services is substantial.”
It is not yet known whether the test can be used for people under 40. The next phase of research will generate further information about its use among premenopausal women.
‘Getting my test result felt like Christmas’
Karen Bonham, 64, had already cut her hair short in preparation for chemotherapy when she was told she did not need to have the treatment. The mum-of-two was diagnosed with breast cancer after a routine screening in 2017.
She underwent a mastectomy to remove a slow-growing cancer that had spread like a spider’s web over 8.5cm, and two affected lymph nodes.
Karen would usually have been offered chemotherapy to reduce the risk of recurrence.
But after joining the OPTIMA trial, she had the Prosigna test. Using her score, doctors decided she should instead receive radiotherapy and hormone therapy.
Former speech and language therapist Karen was walking on the beach near her home in Cardiff when she received a call from the hospital telling her the chemo would not go ahead.
She said: “Time takes on a new dimension while you are waiting for results and appointments within cancer treatment. How to describe the initial feeling? Immense relief? Like Christmas? Certainly a mixture of the two.”
Karen returned to normal family life “quite quickly after treatments”. Nine years later, she remains vigilant for changes in her body but is confident about managing her health with yoga and walking.
She added: “Cancer diagnosis and treatment can be shocking. Life priorities realign — you simply want to survive.
“It has been a positive experience to engage in a research trial. I hope that the trial will bring positive patient outcomes to many.”
