Abstract 

Background Breast magnetic resonance imaging (MRI) has shown high sensitivity in determining tumor extent, multifocality, and occult contralateral breast cancer. Low specificity, unnecessary mastectomies, and costs are argu- ments against MRI. The purpose of this study was to determine whether preoperative breast MRI would affect primary surgical management, reduce reexcision/reopera- tion procedures, and influence the choice of neoadjuvant treatment in patients with newly diagnosed breast cancer. Methods This prospective, randomized, multicenter study included 440 breast cancer patients younger than aged 56 years from three, Swedish, large-volume breast units. Patients were randomly allocated on a 1:1 basis to either 

preoperative staging with breast MRI (n = 220) or no breast MRI (n = 220) (control group). Treatment planning of all patients was discussed at multidisciplinary team conferences. 

Results In patients randomized to the MRI group, who had an observed higher percentage of planned breast-con- serving surgery (BCS) compared with the control group, a change from suggested breast conservation to mastectomy occurred in 23 of 153 (15 %) patients. Breast MRI pro- vided additional information in 83 of 220 (38 %) patients, which caused a change in treatment plan in 40 (18 %). The breast reoperation rate was significantly lower in the MRI group: 11 of 220 (5 %) versus 33 of 220 (15 %) in the control group (p \ 0.001). The number of mastectomies, axillary reoperations, and the number of patients receiving neoadjuvant chemotherapy after definitive treatment did not differ significantly between the groups. 

Conclusions Preoperative staging with breast MRI in women younger than age 56 years altered the treatment plan in 18 % of the patients. Although a higher MRI- related conversion rate from breast conservation to mas- tectomy was found, the final numbers of mastectomies did not differ between the two groups. The breast reoperation rate in the MRI group was significantly reduced. 

Purpose: The Pre-Operative MRI of the Breast (POMB) trial was a randomized, prospective, multicenter trial evaluating the impact of pre-operative breast MRI on treatment regimens and short-term surgical outcomes in women up to 56 years of age with breast cancer. The purpose of this study was to evaluate the performance of pre-operative breast MRI in the POMB trial with respect to incremental MRI findings - over conventional breast imaging methods - and their concordance with histopathology.

Patients and methods: Two-hundred and ten patients (n = 210) participating in the POMB trial underwent preoperative breast MRI at two Swedish breast units. Positive predictive values (PPV) for the incremental MRI findings were calculated for three subgroups of patients with: 1. alteration/alterations of treatment plan; 2. no alteration of treatment plan; and, 3. MRI-related conversion from BCS to mastectomy. Area under the receiver operating characteristic curve (AUC) was calculated using in-breast BI-RADS based ratings for the whole MRI group.

Results: After exclusions a total number of 99 incremental findings in 78 patients were eligible for statistical analysis resulting in a PPV = 74%: (95% CI 60-84%) in 39 patients with MRI related alterations of initial treatment plans and 27%: (95% CI 14-44%) in 39 patients without. Positive predictive values of incremental findings decisive for specific treatment alteration/s were 83% (95% CI 68-92%) in patients with any alteration of initial treatment plans and 91% (95% CI 70-98%) for patients (n = 20/22) with conversion from breast conserving surgery to mastectomy. The empirical AUC for the incremental findings in the whole MRI group was 85% (95% CI 78-91%).

Conclusion: Breast MRI, performed and evaluated together with conventional breast imaging methods can provide relevant information at a high degree of accuracy in the pre-operative setting.

Abstract

Background: Preoperative breast magnetic resonance imaging (MRI) is still controversial as an adjunct to conventional breast cancer workup in terms of the effect on re-excision rates. Our objective was to analyse whether the introduction of preoperative breast MRI influences the rate of re-excisions in women with newly diagnosed breast cancer and to study the additional ipsi- and contralateral MRI findings and their impact on surgical management.

Methods: Women with newly diagnosed breast cancer having preoperative MRI and surgery at Vastmanland County Hospital Breast Unit from January–June 2018 (n = 84) were compared with women not undergoing preoperative MRI from January–June 2016 (n = 97). Data were collected from retrospective reviews of patients’ medical records.

Results: The re-excision rate was one of 84 (1.2%) in 2018 and three of 97 (3.1%) in 2016. There was no statistically significant difference in re-excision rates between the two study periods. In the MRI cohort, seven patients of 84 (8%) had malignancy in the ipsilateral and two (2%) in the contralateral breast not previously detected by conventional imaging. Additional malignant findings were more common in women of age < 59 years, and more often resulted in mastectomy.

Conclusions: Preoperative breast MRI in women with newly diagnosed breast cancer did not reduce the number of re-excisions. Additional malignant findings were more common in women younger than 59 years and influenced surgical management. MRI resulted in no delay of surgery.

ABSTRACT

Background: The value of preoperative breast magnetic resonance imaging (MRI) as an adjunct technique regarding its effect on re-excision rates has been a subject of discussion. No survival data regarding preoperative breast MRI are available from randomized studies. 

Methods: Ten-year follow-up of the previous randomized multicentre study (POMB) was reported, evaluating MRI and its effect on disease-free survival (DFS) and overall survival (OS). A total of 440 patients with newly diagnosed breast cancer were randomized to either preoperative MRI (n = 220) group or conventional imaging (n = 220; control) group. Kaplan–Meier plots were used to analyze DFS and OS. Cox regression was used to estimate hazard ratios (HRs). 

Results: The median follow-up time for each group was 10 years. DFS rates were 85.5% and 80.0% for the MRI and control groups, respectively (P = 0.099). The risk of relapse or death was 46% higher in the control group (HR 1.46, 95% confidence interval 0.93–2.29). OS rates after 10 years were 90.9% and 88.6% for the MRI and control groups, respectively (P = 0.427). The risk of death was 27% higher in the control group (HR 1.27, 95% confidence interval 0.71–2.29). Locoregional, distant, and contralateral recurrence outcomes combined, were increased in the control group (P = 0.048). A subgroup analysis of patients with breast cancer stages I–III showed that preoperative MRI improved DFS compared with conventional imaging but this did not reach statistical significance (P = 0.057). 

Conclusion: After 10 years of follow-up, preoperative breast MRI as an adjunct to conventional imaging resulted in slightly, but non-significantly, improved DFS and OS.

ClinicalTrials.gov Identifier: POMB NCT01859936