Breast Cancer Trials are now recruiting premenopausal women for a new research study.
After showing certain patients with hormone positive receptor breast cancer could achieve good outcomes despite skipping chemotherapy, more participants are needed for an extension study.
The Optimal Personalised Treatment of early breast cancer using Multi-parameter Analysis (OPTIMA) pre-menopausal extension study began recruiting participants in October 2026. Premenopausal women aged 35 to 54 with newly diagnosed hormone receptor-positive breast cancer are eligible to participate.
Participants undergo genomic testing using the Prosigna test, which measures how active the genes involved in breast cancer growth are and provides a genomic risk score.
The extension study is a spin-off from the original OPTIMA study, which involved both men and women over the age of 40 who had recently undergone surgery for newly diagnosed hormone receptor positive breast cancer. The original study found that people whose tumours had a “low” genomic test score could safely receive hormone blocking therapy – without chemotherapy – while achieving similar or better outcomes compared to the patients who received chemotherapy.
Associate Professor Belinda Kiely, a senior medical oncologist from New South Wales, said that traditionally all patients with high-risk cancer were treated with chemotherapy and hormone-blocking therapy, but that many women – especially younger ones – did not necessarily require chemotherapy and the unwanted side effects that come with the treatment.
“In the future, I would like to see all women with hormone receptor positive breast cancer being offered one of these tests when they’re diagnosed, so they can get that information early on to help with their decision-making and planning,” the OPTIMA study chair told media.
Breast Cancer Trials CEO Karen Price encouraged women with breast cancer to speak with their healthcare team about whether participation in a trial like this would be appropriate.
“For many younger women diagnosed with breast cancer, treatment decisions can have lifelong consequences – including on fertility and quality of life,” Ms Price said in a statement. “This study reflects exactly why clinical trials are so important: they help us ask whether we can treat people more precisely, avoid unnecessary side effects, and still protect survival outcomes.”
Samantha Phillips participated in the original OPTIMA trial after she was diagnosed with ER+/PR+ HER2-breast carcinoma in 2024. After being randomised to the arm that avoided chemotherapy, Samantha underwent two surgeries and radiotherapy before ongoing hormone-blocking therapy. She was pleased with how the treatment she received had a smaller impact on her day-to-day life.
“Being clearer on the benefits of the treatment is critical,” she said. “Putting women through treatment that seriously impacts both short-term and long-term quality of life without knowing [whether] it really helps is, in my opinion, too much to ask and doesn’t result in an informed decision.”
“For me, knowing the results of the genomic test through the OPTIMA trial meant I was able to get on with life as I knew it – without having to quit my job or pause my career.”
Further information about the OPTIMA Pre-menopausal extension study is available from the Breast Cancer Trials website.
