OPTIMA Trial: New genomic test could transform personalised breast cancer treatment

Results from the UK led international OPTIMA trial suggest that many women with hormone receptor positive breast cancer could safely avoid chemotherapy, using a genomic test to identify those who may derive just as much benefit from hormone blocking therapy alone. New research presented at the American Society of Clinical Oncology (ASCO) conference has highlighted the growing potential of personalised medicine in breast cancer care.

The findings, reported by The Guardian and other major news outlets, mark a significant step forward in tailoring treatment to the biology of an individual’s cancer, helping reduce unnecessary treatment and the long-term side effects associated with chemotherapy.

The NIHR funded OPTIMA trial followed more than 4,000 patients across the UK and several other countries, and used a genomic test called Prosigna to analyse the activity of 50 genes within tumour tissue. The test identifies the molecular subtype of the cancer and estimates the risk of recurrence, helping clinicians determine whether chemotherapy is likely to provide additional benefit.

For patients with a low genomic risk score, outcomes were almost identical whether they received chemotherapy or not. Five years after treatment, 94% of patients who avoided chemotherapy remained alive and free from recurrence.

This is an important development not only because it could spare many women the physical and emotional burden of chemotherapy, but also because it reflects a broader shift towards more personalised, biology-led approaches to breast cancer care.

At Prevent Breast Cancer, we strongly support research that improves understanding of the biological and genetic factors that influence breast cancer risk, development and treatment response.

This study represents a major step forwards in personalising care for more women (and men) with breast cancer. Prosigna is already approved for use in women after the menopause and those without cancer spread to the lymph nodes under the arm. OPTIMA has shown that the same approach to sparing chemotherapy can also be used in premenopausal women aged 40 and above and in those with up to nine lymph nodes involved with breast cancer. Previously we would always have offered chemotherapy to such women and we now know that, in those with low Prosigna scores, it will only add side effects and no reduction in the chances of the cancer coming back.

This shift towards more personalised treatment also reflects the growing importance of genetic and genomic research in breast cancer more broadly. We support research into inherited genetic risk factors, including BRCA mutations and single nucleotide polymorphisms (SNPs), alongside studies into breast density and risk prediction.

By improving understanding of how genetic variation influences breast cancer risk, researchers hope to develop more advanced predictive tools, including polygenic risk scores, that could help personalise prevention, screening and treatment in the future.

While the OPTIMA trial focuses on using tumour biology to guide treatment decisions after diagnosis, it also demonstrates the wider potential of genomic approaches to deliver more precise and individualised breast cancer care.

The study also reinforces the importance of continued investment in breast cancer research and diagnostic innovation. Personalised medicine relies not only on scientific discovery, but also on access to testing, trained specialists and NHS infrastructure capable of delivering these advances equitably.

As breast cancer remains the most common cancer in women in the UK, developments such as this offer real hope for a future where treatment is better tailored to individual patients.