A major new cancer trial involving Irish women has found that chemotherapy can be avoided in 70% of women with the most common type of early stage breast cancer.

The international trial, known as TAILORx, involved over 10,000 women from 1,182 research units in Ireland, the US, Canada, Australia, New Zealand and Peru. A total of 690 women from Ireland took part in the Irish arm of the trial.

St Vincent's University Hospital in Dublin had the second highest number of participating patients from the 1,182 research units involved.

The Irish arm of the trial was conduced by Cancer Trials Ireland, which is responsible for coordinating cancer trials in this country. Since its establishment in 1996, over 15,000 people have participated in more than 350 cancer trials.

The trial focused on HR positive, HER2-negative, node-negative breast cancer, which is the most common type of early stage breast cancer.

Using a 21-gene expression test, the trial identified 70% of women with a low risk of cancer recurrence after surgery who could avoid chemotherapy. The findings indicate that chemotherapy may be considered for the remaining 30% of women.

According to the Irish arm's lead investigator, Prof Maccon Keane of University Hospital Galway, this trial result ‘is a major advance in precision medicine for women with hormone receptor positive node negative breast cancer'.

"It confirms that using the 21-gene expression test on tumours, we can identify which women will benefit from endocrine (hormone) therapy only, thus eliminating the need for them to have chemotherapy. It also helps identify those women with this disease who really do benefit from the chemotherapy they receive," Prof Keane commented.

He pointed out that by having this trial in Ireland, this has allowed more personalised treatment recommendations for women with this type and stage of breast cancer.

"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," Prof Keane said.

Meanwhile, according to Prof Bryan Hennessy, clinical lead of Cancer Trials Ireland, 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," he said.

Cancer Trials Ireland CEO, Eibhlin Mulroe, added that the fact that so many women in Ireland were able to take part in this trial ‘demonstrates the world-class capability of our unique network of cancer trials research units spread across Ireland'.

"It also reflects the patients' generosity to help future generations. We owe those who took part in this trial our thanks. Not only did these trials provide great relief for women in Ireland who participated and avoided three months of chemotherapy, it delivered considerable cost savings to the HSE," Ms Mulroe noted.

The trial has been ongoing for over 15 years and participating patients are still being followed up. Findings are due to be published in The New England Journal of Medicine.

For more information on Cancer Trials Ireland, click here