An estimated 20% to 40% of patients with HER2-positive metastatic breast cancer will ultimately develop brain metastases, resulting in poorer odds of survival along with headache, seizure, neurological and cognitive impairment, and other quality-of-life challenges.
A recent real-world analysis of metastatic breast cancer in the U.S. found that patients with hormone receptor (HR)-negative/HER2-positive disease had the highest incidence of brain metastasis at the time of first-line therapy initiation (13.1%) -- more than double the average across molecular subtypes -- and in the subsequent 5 years from a metastatic diagnosis (34%).
Prevalence of brain metastases in this group doubled between 12 and 24 months (13% to 25%) and nearly tripled between first- and second-line therapy (11.2% to 31.2%), according to the research.
Citing the analysis for a recent editorial, Sarah Sammons, MD, of Dana-Farber Cancer Institute in Boston, and colleagues said the findings demonstrate the frequent and early occurrence of brain metastases in HR-negative/HER2-positive metastatic disease.
"Moreover, these findings emphasize the importance of ongoing screening clinical trials (particularly at critical time points such as transitions between treatment lines) and have significant clinical implications for the design of screening and prevention trials," they wrote last year in The Breast.
