Prosigna Gene Test Findings from OPTIMA Trial Point to More Personalised Breast Cancer Treatment Decisions

Prosigna Gene Test Findings from OPTIMA Trial Point to More Personalised Breast Cancer Treatment Decisions

(IN BRIEF) The University of Warwick-coordinated OPTIMA trial, sponsored by University College London, has found that the Prosigna genomic test could help many patients with early-stage hormone-sensitive breast cancer avoid unnecessary chemotherapy without compromising outcomes. The trial followed more than 4,400 patients across the UK and internationally, focusing on breast cancer that had spread to nearby lymph nodes, a group where chemotherapy is often recommended as standard treatment. Patients whose care was guided by Prosigna avoided chemotherapy if they had a low test score and received hormone therapy alone instead. More than two thirds of patients in the test-guided group had a low score, and after five years, 93.6% of those who skipped chemotherapy were alive and free from recurrence, compared with 94.8% of those who received chemotherapy. Researchers said the findings mark an important step toward more personalised breast cancer treatment by using tumour biology to guide decisions, and the results are expected to inform NICE guidance on wider NHS access to Prosigna testing.

(PRESS RELEASE) COVENTRY, 1-Jun-2026 — /EuropaWire/ — University of Warwick has coordinated a major breast cancer study showing that a genomic test could help thousands of patients avoid chemotherapy that may offer little or no benefit, while still maintaining strong treatment outcomes. The OPTIMA trial, sponsored by University College London, followed more than 4,400 patients across the UK and internationally, with findings being presented at the American Society of Clinical Oncology Annual Meeting and expected to inform future guidance on wider NHS access to Prosigna testing.

The OPTIMA trial focused on people with early-stage hormone-sensitive breast cancer that had spread from the breast to nearby lymph nodes. Chemotherapy is often offered to patients in this group because it can reduce the risk of the disease returning, but many may receive little or no benefit from it while still facing significant and sometimes dangerous side effects.

The trial used Prosigna, a genomic test that measures the activity of genes linked to breast cancer growth. The test can be carried out on tissue already removed during routine biopsy or surgery and can be run by NHS laboratories with the required equipment.

Patients aged 40 or older who entered the trial after surgery were assigned either to receive standard chemotherapy followed by hormone therapy, or to have their treatment guided by the Prosigna test. In the test-guided group, patients with a low Prosigna score avoided chemotherapy and received hormone therapy alone, while those with a high score received standard treatment.

More than two thirds of patients in the Prosigna-guided group, or 68%, had a low test score. After five years, outcomes were very similar between low-score patients who skipped chemotherapy and those who received it. Among patients who avoided chemotherapy, 93.6% were alive and free from recurrence, compared with 94.8% among those who had chemotherapy.

The results suggest that Prosigna could help many patients safely avoid unnecessary chemotherapy without compromising their outcomes. Statistical analysis indicates that, at most, only 2% of patients with a low score may benefit from chemotherapy.

Professor Janet Dunn, Head of Cancer Trials at Warwick Clinical Trials Unit, said the findings are a strong result for the OPTIMA team because they show that patients with a low Prosigna score can be safely identified and spared chemotherapy, even within a higher-risk patient group.

Professor Rob Stein, Chief Investigator of the OPTIMA trial and Professor of Breast Oncology at the UCL Cancer Institute, said OPTIMA addresses a long-standing challenge in breast cancer care by helping identify which patients truly benefit from chemotherapy and which do not. He said the results mark an important step toward more personalised treatment, using tumour biology to guide decisions rather than relying only on traditional clinical features.

The trial also included patient and public involvement through Adrienne Morgan, co-founder of Independent Cancer Patients’ Voice, who worked alongside the Warwick team. Having previously received chemotherapy herself after a diagnosis of hormone-sensitive breast cancer, she said the trial was urgently needed to prevent patients from being exposed to dangerous and distressing treatment unnecessarily and to reduce avoidable NHS costs.

The study recruited patients from 115 hospitals in the UK, 11 in Norway and Sweden, 44 in Australia and New Zealand, and one in Thailand. It was funded by more than £5.7 million in grants from the National Institute for Health and Care Research to UCL, with Veracyte Inc., the manufacturer of Prosigna, providing around £1.8 million in additional funding and testing support.

One of the trial participants, Karen Bonham, 64, from Cardiff, joined OPTIMA after being diagnosed through routine screening in 2017. After surgery revealed a large hormone-sensitive tumour and two affected lymph nodes, chemotherapy was expected to be the standard next step. However, her Prosigna result showed a low score, meaning she avoided chemotherapy and instead received radiotherapy and hormone therapy. Nearly nine years after diagnosis, she has returned to normal family life and remains active through walking and yoga.

ENDS

Notes to Editors

For more information please contact:

Matt Higgs, PhD | Media & Communications Officer (Warwick Press Office)

Email: Matt.Higgs@warwick.ac.uk | Phone: +44(0)7880 175403

About the University of Warwick

Founded in 1965, the University of Warwick is a world-leading institution known for its commitment to era-defining innovation across research and education. A connected ecosystem of staff, students and alumni, the University fosters transformative learning, interdisciplinary collaboration, and bold industry partnerships across state-of-the-art facilities in the UK and global satellite hubs. Here, spirited thinkers push boundaries, experiment, and challenge convention to create a better world.

Trial Information

In total, 115 hospitals throughout the UK, 11 in Norway and Sweden, 44 in Australia and New Zealand and one in Thailand recruited patients.

The trial was funded by more than £5.7 million in grants from the National Institute for Health and Care Research (NIHR) to UCL. Veracyte Inc., which manufactures the Prosigna test, provided approximately £1.8 million in additional funding and testing support. International partners were supported by local funding sources, including cancer charities.

SOURCE: University of Warwick