Millions of breast cancer patients could safely avoid chemotherapy after scientists developed a DNA-based test that identifies those unlikely to benefit from the treatment, according to BBC News, citing international trial results.
The study suggests that more than two-thirds of patients could be spared chemotherapy and instead treated with hormone therapy alone, avoiding side effects such as fatigue, nausea, hair loss, weakened immunity and fertility issues.
Led by University College London (UCL), the trial involved more than 4,000 newly diagnosed breast cancer patients aged over 40 across the UK, Norway, Sweden, Australia, New Zealand and Thailand.
Researchers used a gene test called Prosigna, which analyses the activity of 50 genes linked to breast cancer growth to estimate the risk of the disease returning, the report said.
Patients who received a low-risk score — around two-thirds of the group — did not undergo chemotherapy.
Their five-year survival rate was 93.7 percent, compared with 94.9 percent among those who received chemotherapy as part of their treatment, according to the report.
The primary treatment for breast cancer is usually surgery to remove tumours, while chemotherapy is often given afterwards to reduce the risk of recurrence.
It is also commonly used in early-stage cases where cancer has spread to nearby lymph nodes.
UCL said clinicians have long questioned whether chemotherapy provides significant benefit for many patients with the most common type of breast cancer.
The university estimated that more than 5,000 NHS patients a year could avoid chemotherapy if the test is widely adopted.
Karen Bonham, from Cardiff, who participated in the trial, told BBC News the findings were an “immense relief” and “feel like Christmas”.
“Cancer diagnosis and treatment can be shocking,” she said. “It certainly propels you into a world of uncertainty. Life priorities realign — you simply want to survive.”
The findings will be presented at the American Society of Clinical Oncology’s annual meeting in Chicago.
Prof David Miles, a leading cancer specialist, told BBC News the results were “practice-changing”.
“We can now confidently predict many patients will get no benefit at all, and therefore there’s no need for them to have the chemotherapy,” he said.
He added: “We used to give chemotherapy to 100 women to benefit 10, knowing that 90 didn’t need it.”
Tanya Hutson, diagnosed with breast cancer in 2022 and treated with chemotherapy, also told BBC News the test was “absolutely amazing”, adding that chemotherapy had been “brutal”.
“For all these people out there who don’t need it but are still getting it — it’s an absolute game changer,” she said.
However, UCL said it is not yet known whether the findings apply to patients under the age of 40, with further research expected in the coming years.
