Does MRI use impact breast cancer treatment?

Preoperative magnetic resonance imaging (MRI) may lead to more aggressive care for breast cancer, including contralateral prophylactic mastectomies, according to the results of a Canadian retrospective cohort study.

Published in JAMA Oncology, the analysis was of information from administrative healthcare databases in Ontario that represented 14 geographic regions. The 53,015 women identified by the authors were treated for primary operable breast cancer from 2003 to 2012. Primary measures included the use of preoperative MRI by year, geographic region, and breast cancer stage.

In 7824 (14.8%) of the cases assessed, preoperative MRI was performed. Over the course of the study period, the use of the technology increased 8-fold across all cancer stages, from 3% to 24% (P < .001 for trend). Factors tied to MRI usage included higher Charlson morbidity score, surgery performed at a teaching hospital, fewer years of surgeon experience, higher socioeconomic status, and younger age.

Multivariate analyses showed that preoperative breast MRI was linked to a higher likelihood of postdiagnosis breast imaging (odds ratio [OR], 2.09; 95% CI, 1.92-2.28), postdiagnosis breast biopsies (OR, 1.74; 95% CI, 1.57-1.93), postdiagnosis imaging to assess for distant metastatic disease (OR, 1.51; 95% CI, 1.42-1.61), mastectomy (OR, 1.73; 95% CI, 1.62-1.85), contralateral prophylactic mastectomy (OR, 1.48; 95% CI, 1.23-1.77), and a longer than 30-day wait to surgery (OR, 2.52; 95% CI, 2.36-2.70).

Researchers concluded that using preoperative MRI leads to a large increase in ancillary investigations, surgery wait time, and contralateral prophylactic mastectomies. The researchers did note some limitations of their study, including lack of detail on whether treatment decisions were altered based on the test results. Lifetime or baseline cancer risks in the cohort also could not be addressed nor could long-term outcomes of recurrence and survival because of the nature of the databases.