Should Providers Screen for Breast Cancer Spread to Brain Before Symptoms Start?

Diagnosing breast cancer at an earlier stage is already associated with a higher survival rate. Recent research presented at the 12th European Breast Cancer Conference (EBCC) held in October found that it could also be beneficial to screen for breast cancer spread to the brain even when a patient is asymptomatic.

When breast cancer spreads to the brain, it is called breast cancer with brain metastases. After lung cancer, breast cancer is the second most frequent cause of brain metastases.

The goal of treating brain metastases is to control the spread of cancer for as long as possible and improve a patient's quality of life.

"The prognosis for patients with breast cancer that has spread to the brain is poor, and survival for these women hasn't improved over the earlier few decades," Elena Laakman, MD, one of the study's authors from the department of gynecology at the University Medical Center Hamburg-Eppendorf in Germany, said in EBCC's press release.

The results of the study showed that when compared to the women with brain metastases who had symptoms, the women who had asymptomatic brain metastasis had three key features in their disease course:

• Fewer and smaller tumors in the brain
• Less aggressive treatments
• Longer survival times

Early Detection Leads to Better Survival

The goal of the research was to find out if there was any advantage to spotting brain metastases before patients developed neurological symptoms. Patients with brain metastases can have:

• Headaches
• Impaired vision
• Nausea or vomiting
• Seizures
• Weakness or Numbness
• Changes in behavior or personality

For the study, the researchers investigated two groups of women with breast cancer with metastasis to the brain from 2000 to 2019. The first group included women who had already exhibited neurological symptoms before brain metastasis detection. In the other group, the women were asymptomatic, and their brain metastasis was detected by chance. 

The study found that women with breast cancer with brain metastasis who had symptoms when the metastases were found had a survival rate of 6.9 months on average. The women with brain metastasis, who had not yet developed symptoms at the time the metastases to the brain were discovered survived, on average, 10.4 months.

"Overall, these results suggest that women may be better off if their brain metastases are diagnosed before they begin to cause symptoms," Laakman said in the press release. However, the suggestion does not align with the current medical guidance regarding breast cancer metastasis to the brain. 

Existing Guidelines and Considerations  

"NCCN (National Comprehensive Cancer Network) guidelines do not currently recommend brain imaging in the absence of signs or symptoms. In my practice, I follow the guidelines," Timothy Byun, MD, a hematologist and medical oncologist with the Center for Cancer Prevention and Treatment at St. Joseph Hospital in Orange County, California, tells Verywell. "There is also emotional (i.e., patient anxiety about the scan results) and financial toxicities (i.e., insurance denial of coverage, patient copay) to consider when ordering imaging studies." 

For this reason, Byun says that he maintains a "very low threshold" when ordering brain imaging for patients who show neurological symptoms. "The initial incidence of brain metastasis for localized breast cancer is still quite low of 1-3%," Byun says. "So it is not justified to order a brain MRI for all breast cancer patients in the absence of symptoms/signs."

Potential Implications of the Study

"I don't think this study changes my pattern of practice," Byun says. "There is currently no high-level evidence data that finding asymptomatic brain metastasis as opposed to symptomatic brain metastasis results in better survival."

Byun notes that because the study was retrospective (looking at historical data) and unrandomized, it needs to be "interpreted with caution" because it has an inherent lead-time bias. 

To counter the bias in future research, Laakmann said, "We now need to carry out a clinical trial to see what happens if we screen high-risk breast cancer patients for brain metastases. This will verify whether doing so could increase survival, symptom control, or quality of life."