MRI-based technique may surpass invasive biopsies for analyzing breast cancer treatment effectiveness

A new MRI-based imaging technique can quickly determine if breast cancer treatments are working effectively, according to a recently published study.

The approach, known as hyperpolarization, magnetizes molecules in a strong magnetic field to assess whether cancer drugs are limiting tumor growth. While the method has only been tested in mouse models thus far, University of Cambridge researchers believe it may eventually replace invasive tissue biopsies.

The group detailed their findings Sept. 22 in Cancer Cell.

“Thanks to advances in cancer treatments, our medicines are becoming more and more targeted, but not all drugs will work in every case—some tumors are resistant to particular drugs,” first author of the study, Susana Ros, PhD, with the Cambridge Cancer Research UK Institute, said Tuesday. “What we need are biomarkers—biological signatures—that tell us whether a drug is working or not."

Nearly 70% of all breast cancers are considered to be estrogen-receptor-positive, with many activating an enzyme (PI3KCA) that allows cancer cells to grow quickly and uncontrollably.

For their research, Ros et al. took these cells from patients and grew them in mouse avatars. They determined that tumors resistant to drugs known as PI3K inhibitors continue to generate FOXM1, a protein involved in regulating cell growth.

Building off this finding, the team developed its hyperpolarization technique which, like a traditional MRI scan, uses an injectable solution to visualize if FOXM1 is present on patients’ images. This biomarker, they noted, indicates a drug isn’t working as it should.

As it stands, patients often must wait a while to understand if their treatment is working. This imaging technique, they noted, could reduce that waiting period and personalize treatments.

“In the future, this could provide us with a rapid assessment of how a breast cancer patient is responding to treatment without the need for invasive biopsies,” said senior study author Kevin Brindle, with the University of Cambridge. “This information could help put an end to giving treatments that are not working and the side effects that accompany them.”