Many women with breast cancer could avoid chemotherapy – what you need to know about genetic test

Business To Business, Cambridge, 2^nd June, 2026:   The new test is a genomic (DNA-based) tumor profiling test that analyzes the activity of specific genes within a breast cancer tumor to estimate the risk that the cancer will return and whether a patient is likely to benefit from chemotherapy.
Rather than relying only on traditional factors such as tumor size, grade, lymph node involvement, and the patient's age, the test examines the tumor's underlying biology. This allows doctors to identify patients whose cancers are less likely to benefit from chemotherapy and who may be treated effectively with other therapies, such as hormone therapy.
How does it work?
The test is performed on a sample of the tumor removed during a biopsy or surgery. It measures the expression of multiple genes associated with cancer growth and recurrence and generates a risk score.
Based on that score, patients can be categorized as:

• Low risk: Chemotherapy may provide little or no additional benefit.
• Intermediate risk: Treatment decisions may depend on additional clinical factors.
• High risk: Chemotherapy is more likely to improve outcomes.

• Fatigue
• Nausea and vomiting
• Hair loss
• Increased infection risk
• Nerve damage
• Potential long-term heart or fertility effects