Precision biomarkers may improve breast cancer treatment

Precision biomarkers have been shown to be an effective tool in cancer care, but most evidence comes from clinical trials rather than real patient experiences.

Christopher Friese, PhD, RN, of the University of Michigan School of Nursing in Ann Arbor, and colleagues are testing how practicing physicians are using a 21-gene recurrence score (RS) biomarker test in breast cancer patients.

The study, surveying 3,880 women being treated for breast cancer, examined how physicians used the RS test to recommend treatment. The study hopes to reveal how breast cancer patients can received improved care with precision technology to reduce overtreatment.

A total 1,527 patients responded to the survey, with 778 receiving an RS to estimate the recurrence risk and measure the potential benefits of chemotherapy in estrogen receptor-positive breast cancer. The study also found a correlation between RS results and chemotherapy—patients with high RS scores were recommended chemotherapy and those with low-risk results were not. Still, a small number of patients with lower RS scores still received chemotherapy.

"We found that most doctors were using tumor genomic tests in ways that were recommended by professional guidelines, although we found that some patients were having the test where there is no professional recommendation for the test," said Friese. "For example, about 13 percent of women whose lymph nodes were positive for breast cancer had tumor genomic testing, even though currently it is still under study whether women with positive lymph nodes will benefit from testing and resulting recommendations."