Millions of breast cancer patients could safely avoid chemotherapy, study suggests

Millions of people with breast cancer could safely avoid chemotherapy as scientists have developed a DNA test that can distinguish between patients who are likely to benefit from the treatment and those who are not, according to trial results.

The international study found that more than two-thirds of its participants could be spared the side of effects of chemotherapy and treated with hormone therapy alone.

Chemotherapy can cause fatigue, nausea, hair loss, a weakened immune system and fertility issues.

The study, led by University College London (UCL), involved more than 4,000 newly diagnosed patients over the age of 40 in the UK, Norway, Sweden, Australia, New Zealand and Thailand.

Scientists used a gene test called Prosigna to measure the activity of 50 genes involved in breast cancer growth and calculate a patient's risk of the disease returning.

Those who received a low score - two-thirds of the group - were not treated through chemotherapy. The five-year survival rate of their group was 93.7%, compared with a 94.9% rate among patients who received chemotherapy as part of their care.

The primary treatment for breast cancer is usually surgery to remove tumours. Chemotherapy is often recommended afterwards to diminish the risk of return.

It is also regularly offered to people with early-stage breast cancer that has spread to the nearby lymph nodes.