An international cancer trial involving Irish doctors and patients has confirmed that a new treatment can significantly reduce the risk of cancer progressing in women with advanced breast cancer.

The PALOMA-2 trial has found that the new drug palbociclib, when taken with the standard hormone therapy, letrozole, slows the progress of cancer among postmenopausal women with advanced (ER-positive, HER2-negative) breast cancer.

Cancer Trials Ireland, which is responsible for coordinating cancer trials in this country, has had a lead role in this trial. According to Dr Janice Walshe, a consultant medical oncologist at St Vincent's University Hospital and Tallaght Hospital, these findings are ‘highly significant' for women with breast cancer which has spread to other parts of their body.

Dr Walshe is the principal investigator of the Irish arm of this trial and is one of the authors of a study on it, which has been published in the New England Journal of Medicine.

"These are very exciting breakthrough findings and have set a new standard for the treatment of this kind of breast cancer. Our trial found that this combination of palbociclib and letrozole slowed the rate of cancer cell growth.

"For patients on the combination, cancer cells stopped growing for just over two years. This compared with 14.5 months for patients taking the standard care drug letrozole alone. That's a 42% increase in the amount of time without cancer growth," she explained.

She said that this means that the need for women with this type of cancer to begin chemotherapy could be delayed.

"This is unprecedented for this patient population and is a material step forward. Breaking this two-year barrier is highly significant," Dr Walshe insisted.

The PALOMA-2 trial involved 666 women from 186 centres in 17 countries, including 22 patients in Ireland, 17 of whom are still receiving treatment on the trial.

PALOMA-2 is set to continue until 2018 in order to determine if this treatment has an effect on the overall survival of patients.

For more information on Cancer Trials Ireland, click here