MRI-Guided Breast Biopsy Could Provide Non-Invasive Evaluation of Response to Neoadjuvant Treatment

For patients with breast cancer receiving neoadjuvant therapy, MRI-guided breast biopsy could be a good way to assess how well they are responding to the treatment, according to the findings from a new study.

In a study published in the Jan. 15 JAMA Network Open, investigators from Memorial Sloan Kettering Cancer Center detailed how they used MRI-guided breast biopsy to correctly assess almost all patients post-chemotherapy. This outcome, they said, indicates that this strategy could give patients and providers an option other than surgical resection.

“This study’s results suggest that the accuracy of MRI-guided biopsy to diagnose a post-[neoadjuvant chemotherapy] [pathologic complete response] approaches that of reference-standard surgical resection,” said the team led by Elizabeth Sutton, M.D., breast MR expert and assistant professor of radiology at Weill Cornell Medical College. “MRI-guided biopsy may be a viable alternative to surgical resection for this population after [neoadjuvant chemotherapy].”

Related Content: Image-Guided Biopsy Picks Up Lingering Breast Cancer

Currently, the only available methods for evaluating a patient’s response to neoadjuvant therapy – treatments administered to side-step more invasive options – is surgical resection. Consequently, the push is on to find non-invasive ways to determine pathologic complete response in this patient group.

Sutton’s group decided to test MRI-guided biopsy because of the modality’s high level of sensitivity. To do this, they enrolled 20 patients between September 2017 to July 2019 into a non-randomized controlled trial. With this sample size, the team said, they had enough participants to accurately evaluate whether the strategy could reach a negative predictive value of at least 85 percent. The biopsy technique surpassed that benchmark, reaching a negative predictive value of nearly 95 percent, they found.

During the study, all participants received standard-of-care neoadjuvant chemotherapy, as well as definitive surgery for the treatment of stage IA to IIIC biopsy-proven operable invasive breast cancer. In addition, they also underwent non-contrast enhanced MRI both prior to and post-neoadjuvant chemotherapy.

Using a 1.5T or 3T whole body MRI scanner, as well as a vacuum-assisted biopsy system, the team removed between seven to 12 tissues samples from each patient via a single incision site which they marked before beginning chemotherapy.

According to their pathological analysis, 11 patients showed no residual cancer evidence, and eight were diagnosed with residual invasive cancer. Only one receive a ductal carcinoma in situ diagnosis. Of this group, the MRI-guided biopsy correctly pinpointed all the patients who did not have residual invasive cancer, but it did return a false-negative to a woman who had a residual cancer that measured less than 0.2 cm. In addition, they said, the MRI-guided biopsy also missed the ductal carcinoma in situ, returning a false negative to that patient, as well.

Overall, the team determined, MRI-guided biopsy offers a negative predictive value of 93 percent for invasive cancer and 86 percent for both in situ and invasive cancers.

“These preliminary results suggest that MRI-guided biopsy was an accurate approach for evaluating the extent of residual disease after [neoadjuvant chemotherapy],” the team concluded. “With an increasing focus on mitigating overtreatment and limiting potential toxic effects and cost, MRI-guided biopsy may be a viable alternative to surgical resection for appropriately selected patients after [neoadjuvant chemotherapy.]”

Still, they stressed, their results are not applicable to other patient populations, and further study around MRI-guided biopsy is needed.

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