A landmark study shows millions of women with breast cancer could skip chemotherapy thanks to a genomic test that determines who needs the treatment and who doesn’t.
The randomised international trial specifically looked at whether the test could identify those patients who would not benefit from chemotherapy, and then see if they could safely avoid it.
Hailed by experts as gamechanging, the results showed that it could. The five-year cancer-free survival rate was 93.7% in the group that skipped chemotherapy, which was statistically non-inferior to the 94.9% rate in patients randomly assigned to receive chemotherapy.
Karen Bonham was one of 4,429 patients with breast cancer recruited to the trial from countries including the UK, Norway, Sweden, Australia, New Zealand and Thailand.
A speech and language therapist originally from Swansea in Wales, Bonham was diagnosed with cancer in 2017 after routine breast screening at the age of 55.
The news was shocking, she said. “It certainly propels you into a world of uncertainty. Life priorities realign – you simply want to survive.”
Dreading having to go through chemotherapy, she agreed to join the Optima trial after undergoing surgery.
The Prosigna genomic test analyses the activity of 50 specific genes in tumour tissue to determine the molecular subtype and develops a risk of recurrence score to help doctors decide if chemotherapy is necessary.
Tissue stored from Bonham’s surgery was analysed while she continued to prepare for standard chemotherapy to begin. She was only days away from starting treatment and said she had already cut her hair short when the results came back in September 2017.
Taking a walk on a Welsh beach, Bonham received a phone call from her hospital informing her she had been allocated to the group of patients that would not be having chemotherapy.
“How to describe the initial feeling? Immense relief? Like Christmas? Certainly a mixture of the two,” she said. Skipping chemotherapy, she had radiotherapy and hormone therapy.
Today, Bonham, now 64, retired and living in Cardiff, is free of cancer, healthy and shows no signs of the disease coming back.
“It is coming up to nine years since my diagnosis,” she said. “I am mindful of my diagnosis, alert to potential changes in my body but do not feel defined by [it]. I walk, enjoy yoga and live well.
“I was able to choose the timing of my retirement and am now enjoying a healthy and active retirement. The Optima trial has been integral to this.”
Not every woman going through breast cancer will be able to skip chemotherapy. For some, the treatment remains necessary and important.
But the results from the trial, to be presented at the American Society of Clinical Oncology’s annual meeting in Chicago this weekend, suggests many women could skip it safely if the genomic testing signals that they can.
Bonham said: “I hope that the trial will bring positive patient outcomes to many.”
