Chemo 'not needed' by 70pc of women with breast cancer
Thousands of breast cancer patients may be safely spared gruelling chemotherapy following a landmark study.
A trial of more than 10,000 women - including 690 Irish women - with the most common form of early breast cancer found the treatment was unnecessary for many after surgery.
Chemotherapy can be avoided for 70pc of women with the most common type of early stage breast cancer, the study found. The findings will lead to a "fundamental change" in how the disease is treated, a leading oncologist said.
It will spare 500 to 600 women in Ireland having chemotherapy annually.
Irish oncologists have been giving progressively less chemotherapy to low risk women as evidence emerged in recent years.
According to the study, more than 20,000 women in the UK are diagnosed with hormone-receptor positive, HER2-negative, node-negative breast cancer annually. Around half of these patients would historically receive chemotherapy after having surgery to remove their tumour, to prevent recurrence of the disease.
However, the results of the TAILORx trial show that only 30pc of women with this particular form of early-stage breast cancer benefit from the treatment.
The study, presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago, is thought to be the largest breast cancer treatment trial ever conducted.
Dr Alistair Ring, consultant medical oncologist at the Royal Marsden NHS Hospital, in London, said: "I think this is a fundamental change in the way we treat women with early-stage breast cancer and will lead to a considerable number of women no longer needing to have chemotherapy."
The Irish arm of the trial was conducted by Cancer Trials Ireland and led by Professor Maccon Keane, consultant medical oncologist, University Hospital Galway, as the chief investigator.
Professor Keane said the test will identify which women will benefit from endocrine (hormone) therapy only.
"It also helps identify those women with this disease who really do benefit from the chemotherapy," he said.
"Irish women contributed significantly to this trial and can be rightly proud of their input into improving care for future women who present with breast cancer."
Commenting on the results, Professor Bryan Hennessy, clinical lead, Cancer Trials Ireland, said: "This is a globally important breast cancer trial. These results will inform clinical decision-making and in future many women with certain types of early-stage breast cancer can avoid chemotherapy, without impacting on the success of their treatment."
The TAILORx trial used the Oncotype DX test which allows doctors to predict the likelihood of the breast cancer returning. The TAILORx study, led by the Montefiore Medical Centre in New York, found women older than 50 with this form of breast cancer and a score of up to 25 did not need chemotherapy. Under 50s with a score of up to 15 can also be spared the treatment, according to the research.