New evidence of low recurrence rates among women with non-metastatic early breast cancer treated with trastuzumab is reassuring, say Australian researchers who have conducted the largest population-based study of outcomes among human epidermal growth factor 2-positive (HER2-positive) patients .

Despite one-third of these patients not completing the standard full year of treatment with trastuzumab, survival outcomes were comparable to those in the landmark clinical trials that helped the drug get PBS listed in 2006, they said.

The monoclonal antibody has been credited with shifting the treatment paradigm of this particularly aggressive cancer sub-type, which is responsible for 15-20% of all breast malignancies.

The study, led by UNSW Sydney’s Centre for Big Data Research in Health, involved nearly 15,000 Australian women diagnosed with HER2-positive breast cancer between 2007 and 2016.