Genomic Test Could Help Some Breast Cancer Patients Skip Chemotherapy

Medical advancements have the potential to bring relief to those living with breast cancer around the world. Groundbreaking developments could improve the quality of life for many people. 

According to the BBC, a gene test called Prosigna may help some breast cancer patients avoid chemotherapy. The test could spare many patients from undergoing a treatment that can cause challenging side effects.

Fatigue, Nausea, Hair Loss, and More
Chemotherapy is widely used to treat cancer, but it can also be a difficult ordeal to go through. It can cause a range of side effects, including fatigue, nausea, hair loss, fertility issues, and a weakened immune system. For many patients, it can be one of the most challenging parts of treatment.

Breast cancer treatment commonly begins with surgery, with chemotherapy often recommended afterward to reduce the risk of the disease returning, The Guardian reports. The Prosigna test could help doctors determine which patients may safely skip chemotherapy.

How the Prosigna Test Guided Breast Cancer Treatment
According to findings presented at the 2026 American Society of Clinical Oncology Annual Meeting, the international OPTIMA trial involved more than 4,000 patients aged 40 and older with ER-positive, HER2-negative early breast cancer who had been recommended chemotherapy. The trial examined whether the Prosigna gene expression test could safely inform decisions about which patients needed chemotherapy. 

The patients were randomly assigned to two groups. The standard-treatment group received chemotherapy followed by hormone therapy. In the test-directed group, those with high Prosigna scores were treated with chemotherapy and hormone therapy, while those with low Prosigna scores were treated with hormone therapy alone. Among patients with low scores, the five-year invasive breast cancer-free survival rate was 94.9 percent in the standard-treatment group and 93.7 percent in the test-directed group. The results met the trial’s predetermined standard for showing that the test-directed approach was not inferior to standard treatment. The findings indicate that patients who meet the trial’s criteria and have a low Prosigna score may safely avoid chemotherapy and receive hormone therapy alone. 

The test could offer major benefits. “For patients, this means many may be spared the physical and emotional burden of chemotherapy and its potential long-term side effects. For health systems, it represents a more efficient and evidence-based use of resources,” Rob Stein, the trial’s chief investigator and a professor of breast oncology at University College London, tells The Guardian. 

A cancer diagnosis can be frightening and life-changing, both because of the disease itself and the challenges encountered as a result of the treatment. As cancer research advances, scientists and doctors are developing more personalized approaches that may improve outcomes while sparing patients from unnecessary side effects. This approach offers a hopeful step in that direction.