Grant: Project Grant

Breast cancer is the type of cancer with the highest incidence, and it represents the second cause of death in women. Several biomarkers such as hormone receptor status expressed in the breast tumors could predict to a certain level the aggressiveness and potential of development into invasive cancer. The Human Epidermal Growth Factor 2, HER2, is a prognostic marker of clinical outcome in breast cancer. High expression of HER2 occurs in 20-25% of breast tumors and has been associated with a more aggressive clinical behavior. Anti-HER2 agents are administered only to patients with HER2-positive (HER2+) breast tumors. Therefore, patients with HER2-negative (HER2-) breast tumors receive no personalized treatments. These women have higher rate of recurrence, and when this happens a change in HER2 status is often observed (i.e. HER2- at primary diagnosis to HER2+ at breast recurrence). Such tumors could therefore benefit from anti-HER2 treatments at time of diagnosis, which currently are not provided for a primary HER2- tumor. This study will establish a breast cancer gene signature that will identify women in whom an anti-HER2 treatment in prevention (i.e. at breast cancer diagnosis) would be beneficial to prevent a breast cancer recurrence. Through lack of better options, these patients are currently treated with aggressive chemotherapeutic agents only. We can thus expect our research to have an impact not only on the incidence of breast cancer recurrence and prognosis, but on response to treatment as well, hence impacting greatly on their quality of life.