DNA Test Could Allow Millions of Breast Cancer Patients to Safely Avoid Chemotherapy

The Prosigna gene test measures the activity of 50 genes involved in breast cancer growth to calculate recurrence risk. A University College London study of more than 4,000 newly diagnosed patients over age 40 found two-thirds received low scores and safely avoided chemotherapy, achieving a 93.7% five-year survival rate compared to 94.9% for those who received chemotherapy. More than 5,000 NHS patients annually could avoid chemotherapy as a result.

Prosigna DNA test

• ▪Patients who received a low Prosigna score were not treated through chemotherapy in the University College London study.
• ▪The Prosigna gene test measures the activity of 50 genes involved in breast cancer growth.
• ▪Two-thirds of participants in the University College London breast cancer study received a low Prosigna score.
• ▪The Prosigna test calculates a patient's risk of breast cancer returning.

Trial survival rates

• ▪The University College London breast cancer study included patients in the UK, Norway, Sweden, Australia, New Zealand and Thailand.
• ▪The five-year survival rate for breast cancer patients who received a low Prosigna score and avoided chemotherapy was 93.7%.
• ▪More than two-thirds of participants in the University College London breast cancer study could be spared the side effects of chemotherapy and treated with hormone therapy alone.
• ▪The University College London breast cancer study involved more than 4,000 newly diagnosed patients over the age of 40.
• ▪It is not known whether the University College London breast cancer study findings apply to people under the age of 40.
• ▪The findings of the University College London breast cancer study will be presented at the American Society of Clinical Oncology's annual meeting in Chicago on June 1, 2026.
• ▪The five-year survival rate for breast cancer patients who received chemotherapy in the University College London study was 94.9%.

Patient testimonials

• ▪Tanya Hutson was diagnosed with breast cancer in 2022 and had chemotherapy as part of her treatment.
• ▪Chemotherapy can cause fatigue, nausea, hair loss, a weakened immune system and fertility issues.
• ▪Karen Bonham avoided chemotherapy thanks to the Prosigna test and received radiotherapy and hormone therapy over eight years.
• ▪Karen Bonham from Cardiff participated in the University College London breast cancer trial.

Clinical practice changes

• ▪Chemotherapy is often recommended after breast cancer surgery to diminish the risk of the disease returning.
• ▪Chemotherapy is regularly offered to people with early-stage breast cancer that has spread to the nearby lymph nodes.
• ▪The primary treatment for breast cancer is usually surgery to remove tumours.
• ▪More than 5,000 NHS patients a year could avoid chemotherapy as a result of the University College London breast cancer trial.
• ▪Professor David Miles described the University College London breast cancer study findings as practice-changing.

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