Preoperative breast MRI can improve surgical outcomes and detect more cancers in younger women with breast cancer, according to new research.
MRI not only reduces the rate of repeat surgery among women under 35 years old without increasing mastectomy rates, MRI can also detect additional cancers with high sensitivity, said researcher Ah Reum Park, MD, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul, Korea.
Park
“While breast cancer is a relatively uncommon occurrence in women under the age of 35, it deserves special consideration as there are several unique challenges in cancer diagnosis at a young age,” Dr. Park said.
For example, breast cancer is more likely to present at advanced stages in patients under 35, and tumors are likely to be more aggressive. For that reason, that population of women is likely to have worse outcomes than older women.
“But despite the proven sensitivity of breast MRI, the role of preoperative breast MRI in newly diagnosed breast cancer remains controversial,” Dr. Park said.
While the potential use of MRI can affect surgical planning, few studies have evaluated the impact of MRI on surgical outcomes in young women. In terms of research that has been done, results have been inconsistent and have not controlled for confounders, Dr. Park said.
Researchers Evaluate Surgical Outcomes
In their study, Dr. Park and colleagues sought to evaluate the association between preoperative breast MRI and surgical outcomes in women 35 years of age or younger, using propensity score analysis, a statistical method used to control for treatment selection bias in observational studies.
Researchers used inverse probability weighting (IPW) and propensity score (PS) matching methods.
The retrospective study conducted at Asan Medical Center between January 2007 and December 2017, comprised 1,508 patients. Of those patients, 964 were included for final analysis.
The remainder of patients were excluded because they either underwent neoadjuvant chemotherapy, had stage IV disease, a history of ipsilateral breast cancer, or had incomplete data. The 964 women included in the study were divided into the MRI group (665) or the non-MRI group (299).
Surgical outcomes were evaluated to distinguish those who had mastectomy performed as initial surgery from those who had any additional surgery and those who after multiple surgeries ultimately required mastectomy.
Dr. Park and colleagues determined that preoperative breast MRI was associated with a reduction in the rate of repeat surgery (odds ratio = 0.126 for IPW and 0.116 for SP) without a significant increase in the overall mastectomy rate (OR=1.235 for IPW and 1.234 for PS matching).
In addition, researchers determined that the use of MRI resulted in a change in surgical planning in 14.9% of cases and that the changes were appropriate 62.6% of the time.
Dr. Park and colleagues also found that MRI identified additional lesions in 26.8% of the patients in the MRI group, and that lesions were malignant in half of those cases.
While the study had limitations, Dr. Park concluded that preoperative breast MRI has the potential to improve surgical outcomes in women younger than 35 years.
“Preoperative MR imaging in this group of patients is useful for detecting additional synchronous malignancy and also for improving surgical outcomes by significantly reducing the rate of repeat surgery and positive resection margin, with a similar likelihood of overall mastectomy,” Dr. Park said.
“Our results show that preoperative MR imaging was associated with favorable surgical outcomes in these patients qualified for the surgical treatment,” Dr. Park said.
A forest plot showing the association between preoperative breast MR imaging and surgical outcomes in the unadjusted and adjusted patients using the IPW and PS matching. Estimated odds ratio of patients in the MR group compared with the no MR group is indicated by a solid rectangle (horizontal lines indicate 95% confidence intervals). IPW= inverse probability weighting, PS = propensity score.
For More Information
View the RSNA 2020 session Preoperative Breast MR Imaging in Young Age Breast Cancer: Benefits in Surgical Outcomes by Using Inverse Probability Weighting — SSBR03 at RSNA2020.RSNA.org.
