Breast cancer is the most common cancer in the UK and is responsible for thousands of deaths each year. Ductal carcinoma in situ (DCIS) is a common type of breast cancer that does not spread, but can mutate over time to become metastatic cancer. DCIS is normally removed surgically, however there is a risk of recurrence after treatment, and it is currently difficult to predict this risk when assessing patients.
This study looked at over 860 patients with DCIS to find ways of predicting whether DCIS is likely to return after surgery or develop into metastatic disease. We found that HER2 expression can predict DCIS recurrence and progression. By screening DCIS patients for HER2, we could ensure that high-risk patients are offered treatments to minimize the chance of recurrence or spread, while lower risk DCIS patients could avoid unnecessary treatment.