A genetic test known as Prosigna could enable younger women with breast cancer to avoid chemotherapy, potentially reducing both treatment side effects and costs within the National Health Service (NHS), according to recent research presented at the European Society of Medical Oncology meeting in Madrid.

Currently, the Prosigna test is approved only for post-menopausal women whose breast cancer has spread to no more than three lymph nodes. However, researchers from University College London have proposed extending its use to women as young as 40 years old. Their study indicates that this approach could save the NHS approximately £654 per patient within the first two years after diagnosis, amounting to an estimated annual saving of around £4 million if implemented broadly.

Breast cancer remains the most common cancer among women in the United Kingdom, with about 60,000 new invasive cases diagnosed each year. Approximately 80% of these cases are oestrogen-receptor-positive, meaning the tumors grow in response to the hormone oestrogen and can often be treated effectively with hormone therapies alone. Despite this, many women still receive chemotherapy, which carries significant side effects including nausea, vomiting, hair loss, and an increased risk of infection. There is a growing concern that chemotherapy may offer little benefit to a substantial proportion of these patients.

The study involved 4,429 women aged 40 and over whose cancer had spread to as many as nine lymph nodes or whose tumor measured 30 millimeters or larger. Prosigna analyzes the expression of 50 genes related to breast cancer growth from tumor samples obtained during surgery or biopsy. Based on gene activity, it generates a risk score predicting the likelihood of cancer recurrence. Women with low-risk scores may safely forgo chemotherapy and rely on hormone therapy alone.

Results demonstrated that about 67% of patients tested could avoid chemotherapy, which translates to roughly 4,200 women annually within the NHS. Researchers noted that chemotherapy costs approximately £5,500 per patient over two years, while the addition of the Prosigna test reduced these costs by an average of £3,611 per patient, according to analysis by Professor Peter Hall of Edinburgh University.

While the study focused on the initial two years following diagnosis, experts believe the financial advantages, as well as the reduced burden of chemotherapy-related side effects, could be even more pronounced over a longer term. The findings support calls for broader use of genetic testing to individualize breast cancer treatment and optimize healthcare resource allocation.