Brain MRI could ID metastases in breast cancer patients, but guidelines don’t recommend it

Though not the guideline-recommended route for treatment, select breast cancer patients could benefit greatly from MRI screenings designed to identify brain metastases, according to a research letter penned this month by Dana-Farber/Brigham and Women’s Cancer Center experts and published in JAMA Oncology.

Such screenings are typically reserved for patients with small cell and non-small cell lung cancer, as well as melanoma, first author Daniel N. Cagney, MD, and colleagues wrote. Those recommendations, while adhering to National Comprehensive Cancer Network (NCCN) guidelines, might be ignoring a key group.

“Brain metastases are common in select patients with breast cancer, as well,” Cagney and co-authors said. “Eight to 11 percent of patients with de novo metastatic human epidermal growth factor receptor 2 positive or triple-negative breast cancer harbor brain metastases, and 46 to 53 percent of such patients develop brain metastases during their clinical course.”

Despite this, the authors wrote, the NCCN has failed to issue brain scanning guidelines for those patient groups. To test that status quo’s efficacy, the team retrospectively analyzed 349 patients with breast cancer, as well as 659 with non-small cell lung cancer, over a period of 15 years, noting intracranial disease burden at presentation, management and outcome.

Compared to those with non-small cell lung cancer, women with breast cancer presented with both larger and more numerous brain metastases, Cagney et al. found. The latter group was also more likely to be symptomatic at presentation, present with seizures, harbor brainstem involvement and receive whole-brain radiation therapy than their counterparts.

“After initial brain-directed therapy, no significant differences in recurrence or treatment-based intracranial outcomes were found between the two groups,” the authors wrote. “However, neurological death was more common in patients with breast cancer than patients with non-small cell lung cancer, both as a percentage of total deaths and as a time-to-event based outcome.”

Because the researchers didn’t find any notable gaps in the patient populations after initial brain-directed therapy, the intracranial disease in patients with breast cancer was likely diagnosed later, rather than being more aggressive or resistant to therapies than in non-small cell lung cancer patients. Still, Cagney et al. said, the findings “strongly” support more research into the subject.

“Brain-directed MRI screening for patients who harbor malignant neoplasms with potential for intracranial involvement is important given the impact of neurological compromise on quality of life,” the group wrote. “In addition, early identification of intracranial disease facilitates less invasive or less toxic approaches, such as stereotactic radiosurgery or careful use of promising systemic agents rather than whole-brain radiation therapy or neurosurgical resection.”