Millions of women with breast cancer could skip chemotherapy in the future, but researchers have developed a DNA test that can distinguish between patients who are likely to benefit from the treatment and those who are unlikely to benefit.
This is revealed by a new international study BBC reports.
According to the study, two out of three could escape chemotherapy for breast cancer and receive hormone therapy instead.
Chemotherapy for cancer can cause various side effects, including fatigue, nausea, hair loss and a weakened immune system.
The study was conducted at University College London (UCL) and included over four thousand newly diagnosed patients in the UK, Norway, Sweden, Australia, New Zealand and Thailand. All had reached the age of 40.
Measure the activity of 50 genes
Researchers used a gene test called Prosigna to measure the activity of 50 genes that contribute to the growth of breast cancer and then calculated the risk of the disease returning.
Those with a low score, as the disease was unlikely to recur, did not receive chemotherapy. Five-year survival in their group was 93.7% compared to 94.4% among patients who received chemotherapy as part of their treatment.
The primary treatment for breast cancer is usually surgery to remove the tumor. Chemotherapy is often recommended afterwards to reduce the risk of the cancer coming back.
The result is relief
Experts worry that chemotherapy has little benefit for those with the most common types of breast cancer.
UCL says that over five thousand patients of the UK health system could escape drug treatment in the future.
Karen Bonham, from Cardiff, took part in the research. She says the result is a great relief, but thanks to the Prosigna test, she has received radiation and hormone treatment for eight years.
