Identification of Risk Factors for Brain Recurrence in Patients With HER2-positive Localised Breast Cancer

HER2 gene amplification, detected in 20% to 30% of breast cancers, was a poor prognostic factor before the advent of anti-HER2 therapies. In the early 2000s, trastuzumab revolutionised the management of patients with HER2-positive (HER2+) breast cancer in the metastatic and localised stages of the disease. At the time of diagnosis of metastatic disease, 7-11% of patients have brain metastases, with (70% of cases) or without symptoms (30% of cases). In the absence of brain metastases, 30% to 50% of patients will develop brain metastases within the first two years of treatment, depending on whether the disease is hormone receptor positive (HR+) or negative (HR-). The presence of brain metastases is the most important prognostic factor. The neurological symptoms caused by the presence of these lesions, but also by the local treatments offered, affect patients' quality of life, although im