Abenaa M. Brewster, MD, MHS

Improving the precision and personalization of breast cancer screening

Impact

Annual breast cancer screening is an important component of preventive healthcare for women. Mammograms, the gold standard for breast cancer screening, are imperfect and less helpful for fast-growing breast cancers, like the estrogen receptor (ER)-negative subtypes. To improve the precision of breast cancer screening, and increase capacity for detecting breast cancer early, Dr. Brewster and her team are working to develop a new liquid biopsy technique to detect cancer with a simple blood-based test. Ideally, this test would allow for more personalized screening, where someone with a positive blood test can be offered more frequent screening—including breast MRI—while someone with a negative blood test would be safely advised to have less frequent screening mammograms or no screening at all. Further, her team is evaluating patients’ perceptions and preferences for this new method of breast cancer detection to evaluate potential barriers.

Progress Thus Far

Dr. Brewster’s team developed a unique liquid biopsy test to detect exosomes, which are small particles secreted by cancer cells into the blood. Preliminary results have shown that the new technology has a few limitations in specificity and sensitivity, compared to standard mammography. They are designing new protocols to optimize the use of the test.

What’s next

The team will refocus their research efforts this year on screening in women with DCIS, who have an elevated risk of developing invasive breast cancer. As a result of the elevated risk, women with DCIS undergo additional screening, preventive therapy, and often surgical intervention. Many are overtreated and never develop invasive breast cancer. A recent study by the Human Tumor Atlas Network (HTN) identified several hundred genes that can predict recurrence and disease progression in patients with DCIS. Dr. Brewster plans to build upon this landmark study by investigating genomic similarities between DCIS and subsequent invasive breast cancer vis á vis the identified genes. Her team will also investigate gene expression changes by patients’ race and ethnicity to determine if these factors contribute to a higher risk of invasive breast cancer. The results from these studies may help explain why some women with DCIS develop invasive breast cancer and others do not, equipping patients and their doctors with more information to inform personalized decision-making for patients with DCIS.