Skipping Chemo for Breast Cancer: Australian Trial Opens for Women 35-54

The result would show whether a woman can safely skip chemotherapy and its side effects while achieving the same or better health outcomes.

Why the trial matters

Dr Nick Zdenkowski, the medical adviser for Breast Cancer Trials, called the study "monumental". He said the hormone receptor-positive subtype accounts for around 75 per cent of breast cancers.

About 20 per cent of women with breast cancer are under age 50, he said. "Breast cancer in younger women tends to have a poorer outcome and the incidence is gradually increasing in this group. We don't exactly know why," he said.

That is one reason doctors lean toward chemotherapy for younger women, who tend to have a worse prognosis than post-menopausal women, Zdenkowski said.

Building on the original Optima trial

The new study expands on the original Optima trial. That trial found people aged 40 and over with early-stage breast cancer could be treated safely with hormone-blocking therapy and avoid chemo.

It included "relatively few patients on this trial who were premenopausal, meaning this study is needed to make a definitive conclusion", Zdenkowski said.

Patients in the new trial would still have surgery, radiotherapy and endocrine therapy. Hormone-blocking drugs remain the main and most effective treatment for this type of cancer, he said.

Chemotherapy can stop the ovaries from functioning, which reduces the oestrogen that could feed any cancer cells. Zdenkowski said doctors can achieve that effect "through different, more acceptable ways than chemotherapy, with fewer long-term side effects".

He said the aim is to spare women the side effects of chemotherapy, time off work, costs and impact on their family. Long-term effects include fatigue, memory and concentration loss, and nerve damage in fingers and toes.

A test that costs $3500

The genomic test is used in Australia and other countries, but it is not funded in Australia. It currently costs $3500, according to Zdenkowski.

"As an oncologist, I've got patients who regularly fork out from their own pocket for this test so they can try to avoid having chemotherapy," he said. Three of his patients have paid for it in recent weeks.

"But there's a lot of inequity because many people can't afford the test," he said.

Veracyte, the company that owns the rights to the test, plans to apply for funding through the Medical Services Advisory Committee (MSAC). Zdenkowski said he is optimistic because the test "ticks a lot of boxes".

Samantha Phillips, of Western Sydney, was diagnosed in 2024 at age 46 after her partner noticed an indentation in her breast. "There are times that I wonder if the treatment isn't worse than the cancer itself," she said. "Being able to be clearer on the benefits of the treatment is critical."