Triple-negative and HER2-overexpressing breast cancers exhibit an elevated risk and an earlier occurrence of cerebral metastases

Abstract Purpose Evaluation of the influence of immunohistochemically defined breast cancer (BC) subtypes and other risk factors on the development of cerebral metastases (CM). Methods Exploratory analysis of a hospital-based prospective tumour registry including all patients with primary BC treated in our EUSOMA breast unit between 1998 and 2006. Results The study cohort contained 2441 patients, including 284 patients (11.6%) with triple-negative (oestrogen receptor (ER), progesterone receptor (PR) and HER2-negative) and 245 patients (10.1%) with HER2-overexpressing BC subtypes. Overall, 80 patients (3.3%) developed CM within a median follow-up period of 47 months, 19 (23.8%) of them with triple-negative and 19 (23.8%) with HER2-positive tumours. Therefore, 6.7% of all patients with triple-negative and 7.8% of patients with HER2-positive breast cancer developed CM. Multivariate analysis indicated that the highest risk for CM was triple-negative breast cancer. Further independent risk factors were: HER2-overexpression, early onset BC (age  Conclusion Patients with triple-negative or HER2-positive BC have a higher risk for CM compared with patients bearing the ER+/HER2- phenotype and develop CM earlier in the course of disease. A risk profile for CM might help adjust surveillance in high risk populations and identify patients with a need for new treatment strategies.