MRIs May Lower Breast Cancer Deaths From Variants in 3 Genes

Women who get annual magnetic resonance imaging (MRI) screenings starting at aged 30 to 35 years could reduce breast cancer mortality by more than 50% among those who have certain genetic changes in 3 genes, according to the results of a comparative modeling analysis published in JAMA Oncology.

The analysis involves the pathological variants in the ATM, CHEK2, PALB2 genes, which collectively are as prevalent as the BRCA1/2 gene mutations.

The findings support MRI screening for these women earlier than existing preventive-care guidelines propose, according to the study’s investigators.

“Screening guidelines have been difficult to develop for these women, because there haven’t been clinical trials to inform when to start and how to screen,” Kathryn Lowry, MD, an assistant professor of radiology at the University of Washington School of Medicine, said in a statement.

The comparative modeling analysis was a collaboration among the Breast Cancer Surveillance Consortium, the Cancer Intervention and Surveillance Modeling Network, and the Cancer Risk Estimates Related to Susceptibility (CARRIERS) consortium.

Investigators input age-specific risk estimates provided by CARRIERS and recent published data for screening performance into the simulation models. CARRIERS provided data on more than 32,000 individuals with breast cancer and a similar number of individuals who did not have cancer.

“For women with pathogenic variants in these genes, our modeling analysis predicted a lifetime risk of developing breast cancer at 21% to 40%, depending on the variant,” Lowry said. “We project that starting annual MRI screening at age 30 to 35, with annual mammography starting at age 40, will reduce cancer mortality for these populations of women by more than 50%.”

The simulations compared the performance of both mammographies and MRIs against mammography alone. It also projected that annual MRIs conferred significant additional benefit to the populations.

Additionally, mammograms starting earlier than aged 40 years did not have a meaningful benefit and increased false-positive screenings, Lowry said.

The simulations in the study also predicted the volume of false-positive screening results and benign biopsies, per 1000 women scanned, that would accompany the author’s recommendations for annual MRIs starting earlier.

The results showed about 4 false-positive screening results and 1 to 2 benign biopsies per women over a 40-year screening span, the investigators said.

To benefit fully from the cancer screening guidelines based on genetic susceptibility, an individuals would need to know that she carries an implicated gene variant before receiving a disease diagnosis.

Often, individuals get a genetic test panel administered after they test positive for cancer, which is too late to have preventive value for the individual but is potentially lifesaving for blood relatives who could seek genetic testing.

“People understand very well the value of testing for variants in BRCA1 and BRCA2, the most common breast cancer predisposition genes. These results show that testing other genes, like ATM, CHEK2, and PALB2, can also lead to improved outcomes,” Mark Robson, MD, chief of Breast Medicine Service at Memorial Sloan Kettering Cancer Center, said in the statement.

Investigators hope that the analysis will aid organizations that issue guidance for medical oncologists and radiologists.

Reference

MRI may lower breast cancer deaths from variants in 3 genes. EurekAlert. News release. February 17, 2022. Accessed February 18, 2022. https://www.eurekalert.org/news-releases/943453