July 2022: HER2-positive breast cancer patients with brain metastases have the best prognosis compared to other tumor subtypes

This study aimed to characterize the cohort of HER2-positive breast cancer patients (HER2 positive in the primary breast cancer histology) with brain metastases (BMs) and to compare the clinical characteristics of this cohort with patients with TNBC or luminal-like breast cancer. Luminal-like was defined as estrogen receptor (ER) and/or progesterone receptor (PgR)-positive and HER2-negative breast cancer. In this study, luminal-A- and B-like patients were treated as one collective cohort. Additional aims were to characterize the subcohort of HER2-positive/hormone receptor-positive (ER and/or PgR receptor positive) breast cancer patients with BMs and to compare the clinical characteristics of this subcohort with HER2-positive/hormone receptor-negative (ER and PgR receptor-negative) breast cancer patients with BMs as well as to estimate and compare the overall survival (OS) and progression-free survival (PFS) after the diagnosis of BMs, including the brain PFS and extracranial PFS, in different breast cancer subtypes. A total of 2948 patients from the Brain Metastases in Breast Cancer (BMBC) registry were available for this analysis, of whom 1311 had primary tumors with the HER2-positive subtype.

Highlights

• Patients with HER2-positive BMs from breast cancer have the best prognosis compared with other tumor subtypes.
• Among HER2-positive patients, hormone receptor-positive patients have the longest survival.
• HER2-targeted therapy is significantly associated with a better prognosis in patients with BMs.
• On average, two HER2-targeted therapy lines were administered prior to the development of BMs.
• New compounds are urgently needed to improve the outcome of this subgroup of patients.

Conclusion: We identified factors associated with the prognosis of HER2-positive patients with BMs. Further research is needed to understand the factors determining the longer survival of HER2-positive/hormone receptor-positive patients.

Laakmann E, Witzel I, Neunhöffer T, et al. Characteristics of patients with brain metastases from human epidermal growth factor receptor 2-positive breast cancer: subanalysis of Brain Metastases in Breast Cancer Registry. ESMO Open. 2022 Jun;7(3):100495. doi: 10.1016/j.esmoop.2022.100495.

• PubMed Link:https://pubmed.ncbi.nlm.nih.gov/35653983/