Early identification and treatment of breast cancer spread to the brain

Those diagnosed with the aggressive HER2+ subtype of breast cancer are at high risk of developing secondary tumours (metastasis) in the brain.

Despite the introduction of HER2-targeted therapies for advanced breast cancer, the incidence of patients developing secondary brain cancer is increasing.

This has been attributed in part to improved control of the disease in other organs that extends the life of patients and to the lack of efficacy of HER2-targeting drugs against brain metastasis due to the development of resistance and/or limited drug permeability in the brain.

Currently it’s not possible to predict which patient will develop brain metastases, and there is no routine monitoring meaning patients are often diagnosed too late, when neurological symptoms are already apparent.

Once brain metastasis is detected, patients cannot be cured so there is an urgent need to identify biomarkers that can predict the development of brain metastasis and more effective therapies that would enable patients with HER2+ breast cancer at risk to be identified and treated earlier to improve clinical outcome.

Dr Normand Pouliot and his team will use a unique mouse model that closely mimics the spread of Her2 breast cancer to brain to identify new genes that cause brain metastasis and/or that predict breast cancer spread to brain.

They are seeking to identify a “gene signature” specific to HER2+ brain metastasis which can be used to identify high risk patients prior to the development of brain lesions. These patients could then be closely monitored, allowing for earlier detection and more effective therapeutic interventions tailored to the individual patient.

They will also test novel combination therapies aimed at preventing the emergence of resistance to HER2-targeting drugs and improve their efficacy against HER2+ brain metastasis.