DCIS is a precursor of breast cancer where the cancerous cells are contained within the milk-making ducts. Without treatment, commonly a combination of breast-conserving surgery and radiotherapy, up to half of patients will see the disease return, either as DCIS or as invasive breast cancer.
“We regularly measureoestrogen receptor (ER) levels in patients with DCIS, but our findings suggest that the additional information from testing for human epidermal growth (HER2), which is routine for patients with more advanced disease, could allow us to better identify those most at risk of invasive relapse. These tests are cheap and easy to carry out and could help some patients avoid unnecessary treatment,” added Professor Bundred.
It is currently not possible to predict which cases will progress; so all women are offered radical treatment, potentially unnecessarily.