Breast Cancer Subtype and Brain Metastasis Risk at Diagnosis

Breast cancer subtype influences the probability that a patient has brain metastases at the time of diagnosis, according to an analysis of the US National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database. The study was published in JAMA Oncology.¹

“The findings lend support to consideration of screening imaging of the brain for patients with HER2-positive or triple-negative subtypes and extracranial metastases,” reported Ayal Aizer, MD, MHS, of the department of radiation oncology at Brigham and Women’s Hospital in Boston, Massachusetts, and coauthors.

The authors analyzed survival among 231,684 patients diagnosed with breast cancer and known status for metastatic brain tumors between 2010 and 2013, of whom 968 (0.41%) had brain metastases at diagnosis.

Brain metastases were noted at diagnosis for 7.6% of patients with any metastatic disease, but approximately 11.5% of patients with hormone receptor (HR)-negative, human epidermal growth factor receptor 2 (HER2)-positive, or triple-negative breast cancer subtypes had brain metastases at diagnosis, the research team reported.

Of the 968 patients with brain metastases, 57 were 18 to 40 years old, 423 were 41 to 60 years old, 425 were 61 to 80 years old, and 63 were older than 80 years at diagnosis.

Mean survival among patients with brain metastasis was 10 months for the entire cohort. Among patients with HR-negative, HER2-positive disease, median survival was 21 months, and those with triple-negative disease survived a median of 6 months.

The study included data on brain metastases noted at the time of initial breast cancer diagnosis only, and therefore could not account for the subsequent development of brain metastases.

Reference

1. Martin AM, Cagney DN, Catalano PJ, et al. Brain metastases in newly diagnosed breast cancer: a population-based study. JAMA Oncol. 2017 Mar 16. doi: 10.1001/jamaoncol.2017.0001 [Epub ahead of print]