Disparities in the Use of Preoperative Breast Magnetic Resonance Imaging After Breast Cancer Diagnosis

PURPOSE

Preoperative magnetic resonance imaging (MRI) after breast cancer diagnosis is increasingly used to improve locoregional staging, particularly among women with dense breasts, extensive ductal carcinoma in situ, and lobular histology. The goals of this study were to (1) assess whether use of preoperative MRI varies by race and insurance type; and (2) determine whether preoperative MRI is associated with downstream surgical management.

MATERIALS AND METHODS

We performed a retrospective cohort study of women with stage 0-III breast cancer who were treated with surgical resection within our academic health system (2016-2019). Patients were categorized by race and insurance type. The primary outcome was receipt of preoperative MRI. Secondary outcomes included surgery extent (lumpectomy v mastectomy) and receipt of a second operation.

RESULTS

A total of 1,410 women (27% Black, 73% White; 67% private insurance, 26% Medicare, 6% Medicaid) were included. Black patients were significantly less likely to undergo preoperative MRI than White patients (odds ratio [OR], 0.54 [95% CI, 0.38 to 0.76]; P < .001). There was no association between insurance type and preoperative MRI (Medicare v private: OR, 0.77 [95% CI, 0.52 to 1.15]; P = .208; Medicaid v private: OR, 0.67 [95% CI, 0.36 to 1.25]; P = .210). White patients who underwent preoperative MRI were less likely to undergo lumpectomy versus those who did not (OR, 0.53 [95% CI, 0.37 to 0.76]; P < .001). Likelihood of re-excision was lower for Black women who had undergone MRI versus those who had not (OR, 0.43 [95% CI, 0.20 to 0.93]; P = .031).

CONCLUSION

Black patients were less likely than White patients to undergo preoperative MRI, yet Black women who underwent MRI were less likely to require re-excision. Standardizing preoperative MRI use may mitigate provider- and system-level biases and promote more equitable care.

Preoperative breast MRI positively impacts surgical outcomes of needle biopsy-diagnosed pure DCIS: a patient-matched analysis from the MIPA study

OBJECTIVES

To investigate the influence of preoperative breast MRI on mastectomy and reoperation rates in patients with pure ductal carcinoma in situ (DCIS).

METHODS

The MIPA observational study database (7245 patients) was searched for patients aged 18-80 years with pure unilateral DCIS diagnosed at core needle or vacuum-assisted biopsy (CNB/VAB) and planned for primary surgery. Patients who underwent preoperative MRI (MRI group) were matched (1:1) to those who did not receive MRI (noMRI group) according to 8 confounding covariates that drive referral to MRI (age; hormonal status; familial risk; posterior-to-nipple diameter; BI-RADS category; lesion diameter; lesion presentation; surgical planning at conventional imaging). Surgical outcomes were compared between the matched groups with nonparametric statistics after calculating odds ratios (ORs).

RESULTS

Of 1005 women with pure unilateral DCIS at CNB/VAB (507 MRI group, 498 noMRI group), 309 remained in each group after matching. First-line mastectomy rate in the MRI group was 20.1% (62/309 patients, OR 2.03) compared to 11.0% in the noMRI group (34/309 patients, p = 0.003). The reoperation rate was 10.0% in the MRI group (31/309, OR for reoperation 0.40) and 22.0% in the noMRI group (68/309, p < 0.001), with a 2.53 OR of avoiding reoperation in the MRI group. The overall mastectomy rate was 23.3% in the MRI group (72/309, OR 1.40) and 17.8% in the noMRI group (55/309, p = 0.111).

CONCLUSIONS

Compared to those going directly to surgery, patients with pure DCIS at CNB/VAB who underwent preoperative MRI had a higher OR for first-line mastectomy but a substantially lower OR for reoperation.

CLINICAL RELEVANCE STATEMENT

When confounding factors behind MRI referral are accounted for in the comparison of patients with CNB/VAB-diagnosed pure unilateral DCIS, preoperative MRI yields a reduction of reoperations that is more than twice as high as the increase in overall mastectomies.

KEY POINTS

• Confounding factors cause imbalance when investigating the influence of preoperative MRI on surgical outcomes of pure DCIS. • When patient matching is applied to women with pure unilateral DCIS, reoperation rates are significantly reduced in women who underwent preoperative MRI. • The reduction of reoperations brought about by preoperative MRI is more than double the increase in overall mastectomies.

A Multi-institutional Analysis of Factors Influencing the Rate of Positive MRI Biopsy Among Women with Early-Stage Breast Cancer

BACKGROUND

The use of preoperative magnetic resonance imaging (MRI) for early-stage breast cancer (ESBC) is increasing, but its utility in detecting additional malignancy is unclear and delays surgical management (Jatoi and Benson in Future Oncol 9:347-353, 2013. https://doi.org/10.2217/fon.12.186 , Bleicher et al. J Am Coll Surg 209:180-187, 2009. https://doi.org/10.1016/j.jamcollsurg.2009.04.010 , Borowsky et al. J Surg Res 280:114-122, 2022. https://doi.org/10.1016/j.jss.2022.06.066 ). The present study sought to identify ESBC patients most likely to benefit from preoperative MRI by assessing the positive predictive values (PPVs) of ipsilateral and contralateral biopsies.

METHODS

A retrospective cohort study included patients with cTis-T2N0-N1 breast cancer from two institutions during 2016-2021. A "positive" biopsy result was defined as additional cancer (PositiveCancer) or cancer with histology often excised (PositiveSurg). The PPV of MRI biopsies was calculated with respect to age, family history, breast density, and histology. Uni- and multivariate logistic regression determined whether combinations of age younger than 50 years, dense breasts, family history, and pure ductal carcinoma in situ (DCIS) histology led to higher biopsy yield.

RESULTS

Of the included patients, 447 received preoperative MRI and 131 underwent 149 MRI-guided biopsies (96 ipsilateral, 53 contralateral [18 bilateral]). PositiveCancer for ipsilateral biopsy was 54.2%, and PositiveCancer for contralateral biopsy was 17.0%. PositiveSurg for ipsilateral biopsy was 62.5%, and PositiveSurg for contralateral biopsy was 24.5%. Among the contralateral MRI biopsies, patients younger than 50 years were less likely to have PositiveSurg (odds ratio, 0.02; 95% confidence interval, 0.00-0.84; p = 0.041). The combinations of age, density, family history, and histology did not lead to a higher biopsy yield.

CONCLUSION

Historically accepted factors for recommending preoperative MRI did not appear to confer a higher MRI biopsy yield. To prevent delays to surgical management, MRI should be carefully selected for individual patients most likely to benefit from additional imaging.

Screening and diagnostic breast MRI: how do they impact surgical treatment? Insights from the MIPA study

OBJECTIVES

To report mastectomy and reoperation rates in women who had breast MRI for screening (S-MRI subgroup) or diagnostic (D-MRI subgroup) purposes, using multivariable analysis for investigating the role of MRI referral/nonreferral and other covariates in driving surgical outcomes.

METHODS

The MIPA observational study enrolled women aged 18-80 years with newly diagnosed breast cancer destined to have surgery as the primary treatment, in 27 centres worldwide. Mastectomy and reoperation rates were compared using non-parametric tests and multivariable analysis.

RESULTS

A total of 5828 patients entered analysis, 2763 (47.4%) did not undergo MRI (noMRI subgroup) and 3065 underwent MRI (52.6%); of the latter, 2441/3065 (79.7%) underwent MRI with preoperative intent (P-MRI subgroup), 510/3065 (16.6%) D-MRI, and 114/3065 S-MRI (3.7%). The reoperation rate was 10.5% for S-MRI, 8.2% for D-MRI, and 8.5% for P-MRI, while it was 11.7% for noMRI (p ≤ 0.023 for comparisons with D-MRI and P-MRI). The overall mastectomy rate (first-line mastectomy plus conversions from conserving surgery to mastectomy) was 39.5% for S-MRI, 36.2% for P-MRI, 24.1% for D-MRI, and 18.0% for noMRI. At multivariable analysis, using noMRI as reference, the odds ratios for overall mastectomy were 2.4 (p < 0.001) for S-MRI, 1.0 (p = 0.957) for D-MRI, and 1.9 (p < 0.001) for P-MRI.

CONCLUSIONS

Patients from the D-MRI subgroup had the lowest overall mastectomy rate (24.1%) among MRI subgroups and the lowest reoperation rate (8.2%) together with P-MRI (8.5%). This analysis offers an insight into how the initial indication for MRI affects the subsequent surgical treatment of breast cancer.

KEY POINTS

• Of 3065 breast MRI examinations, 79.7% were performed with preoperative intent (P-MRI), 16.6% were diagnostic (D-MRI), and 3.7% were screening (S-MRI) examinations. • The D-MRI subgroup had the lowest mastectomy rate (24.1%) among MRI subgroups and the lowest reoperation rate (8.2%) together with P-MRI (8.5%). • The S-MRI subgroup had the highest mastectomy rate (39.5%) which aligns with higher-than-average risk in this subgroup, with a reoperation rate (10.5%) not significantly different to that of all other subgroups.

Current Trends in the Utilization of Preoperative Breast Magnetic Resonance Imaging Among Women With Newly Diagnosed Breast Cancer

PURPOSE

The clinical benefit of preoperative breast magnetic resonance imaging (MRI) for early-stage breast cancer (BC) remains controversial. We examined trends and the associated factors of preoperative breast MRI use.

METHODS

This study cohort, constructed from Optum Clinformatics database, included women with early-stage BC who had a cancer surgery between March 1, 2008, and December 31, 2020. Preoperative breast MRI was performed between the date of BC diagnosis and index surgery. Multivariable logistic regressions, one for elderly (65 years and older) and the other for non-elderly patients (younger than 65 years), were performed to examine factors associated with the use of preoperative MRI.

RESULTS

Among 92,077 women with early-stage BC, the crude rate of preoperative breast MRI increased from 48% in 2008 to 60% in 2020 for nonelderly and from 27% to 34% for elderly women. For both age groups, non-Hispanic Blacks were less likely (odds ratio [OR]; 95% CI, younger than 65 years: 0.75, 0.70 to 0.81; 65 years and older: 0.77, 0.72 to 0.83) to receive preoperative MRI than non-Hispanic White patients. Across Census divisions, the highest adjusted rate was observed in Mountain division (OR compared with New England; 95% CI, younger than 65 years: 1.45, 1.27 to 1.65; 65 years and older: 2.42, 2.16 to 2.72). Other factors included younger age, fewer comorbidities, family history of BC, axillary node involvement, and neoadjuvant chemotherapy for both age groups.

CONCLUSION

The use of preoperative breast MRI has steadily increased. Aside from clinical factors, age, race/ethnicity, and geographic location were associated with preoperative MRI use. This information is important for future implementation or deimplementation strategies of preoperative MRI.

Preoperative Breast MRI: Current Evidence and Patient Selection

Breast MRI is the most sensitive imaging modality for the assessment of newly diagnosed breast cancer extent and can detect additional mammographically and clinically occult breast cancers in the ipsilateral and contralateral breasts. Nonetheless, appropriate use of breast MRI in the setting of newly diagnosed breast cancer remains debated. Though highly sensitive, MRI is less specific and may result in false positives and overestimation of disease when MRI findings are not biopsied prior to surgical excision. Furthermore, improved anatomic depiction of breast cancer on MRI has not consistently translated to improved clinical outcomes, such as lower rates of re-excision or breast cancer recurrence, though there is a paucity of well-designed studies examining these issues. In addition, current treatment paradigms have been developed in the absence of this more accurate depiction of disease span, which likely has limited the value of MRI. These issues have led to inconsistent and variable utilization of preoperative MRI across practice settings and providers. In this review, we discuss the history of breast MRI and its current use and recommendations with a focus on the preoperative setting. We review the evidence surrounding the use of preoperative MRI in the evaluation of breast malignancies and discuss the data on breast MRI in the setting of specific patient factors often used to determine breast MRI eligibility, such as age, index tumor phenotype, and breast density. Finally, we review the impact of breast MRI on surgical outcomes (re-excision and mastectomy rates) and long-term breast recurrence and survival outcomes.

The Association of Preoperative Magnetic Resonance Imaging (MRI) With Surgical Management in Patients With Early-Stage Breast Cancer

INTRODUCTION

The rate of mastectomy in lumpectomy-eligible patients with unilateral breast cancer is increasing. We sought to investigate the association between magnetic resonance imaging (MRI) and surgical management of patients with early-stage breast cancer by comparing the rate of mastectomy as first surgery in patients with and without preoperative MRI.

METHODS

A bi-institutional retrospective study included patients diagnosed between 2016 and 2020. Lumpectomy-eligible patients with in situ and invasive cancer were included. Those receiving preoperative therapy, MRI before diagnosis, or with known bilateral cancer were excluded. The risk factors for bilateral and multicentric disease were accounted for. Fisher's exact and chi-square tests compared categorical variables, Wilcoxon two-sample test analyzed continuous variables, and multivariate analyses were performed with Poisson regression.

RESULTS

Four hundred twenty-eight participants met inclusion criteria. Patients who received MRI were younger (58 versus 67 y; P < 0.001) and had denser breasts (group 3 or 4; 61% versus 25%; P < 0.001). Mastectomy rate was twice as high in patients undergoing MRI (32% versus 15%, rate ratio 2.16; P < 0.001), which remained significant in multivariate analysis (rate ratio 2.0; P < 0.001). Contralateral mastectomy (12% versus 4%; P = 0.466) and reexcision (13% versus 12%; P = 0.519) rates were similar. Time to surgery was greater in those receiving MRI alone and MRI biopsy (34 [no MRI] versus 45 [MRI] versus 62 [MRI biopsy]; P < 0.001 for both).

CONCLUSIONS

MRI receipt is associated with a doubled rate of mastectomy in lumpectomy-eligible patients. Future work is needed to standardize patient selection for MRI to those with the highest likelihood of having additional undiagnosed disease.

Preoperative MRI and Its Impact on Surgical Outcomes in Patients with Triple Negative Breast Cancer Treated with Primary Surgery: Did New Margin Guidelines or Cavity Shave Margins Practice Diminish the Role of Preoperative MRI?

BACKGROUND

Results of an earlier retrospective study from our institution suggested that patients with triple negative breast cancer (TNBC) who had preoperative MRI may have had an improved local recurrence rate (LRR) after breast conserving surgery (BCS). We aimed to clarify the impact of preoperative MRI on surgical outcomes in an expanded TNBC cohort treated by BCS in a contemporary era.

METHODS

Our study cohort comprised 648 patients with TNBC who underwent BCS between 2009 and 2018. Demographic and clinical characteristics were compared between those with (n = 292, 45.1%) and without (n = 356, 54.9%) preoperative MRI. Multivariable logistic regression was performed to assess the association of preoperative MRI with surgical outcomes.

RESULTS

The crude LRR of 3.5% was lower than previously reported. Univariable analyses demonstrated that the LRR and re-excision rates in the MRI and no-MRI groups were 3.4 and 3.7%, 21.6% and 27.2%, p = 0.876 and p = 0.10, respectively. Multivariable logistic regression analyses demonstrated that preoperative MRI was not associated with a lower LRR: odds ratio (OR) = 1.42 (p = 0.5). During our study period, new margin guidelines and shave margins practice were adopted in 2014 and 2015. To account for their effects, the year of diagnosis/surgery and other clinical variables were adjusted in multivariable logistic regression and inverse probability weighting models to demonstrate that preoperative MRI remained associated with a lower re-excision risk, OR 0.56, p = 0.04l; and a lower re-excision rate, 23.15% versus 36.0%, p < 0.01, respectively.

CONCLUSIONS

Our findings suggested that patients with TNBC anticipating BCS may benefit from preoperative MRI.

Perioperative magnetic resonance imaging in breast cancer care: Distinct adoption trajectories among physician patient-sharing networks

BACKGROUND

Despite no proven benefit in clinical outcomes, perioperative magnetic resonance imaging (MRI) was rapidly adopted into breast cancer care in the 2000's, offering a prime opportunity for assessing factors influencing overutilization of unproven technology.

OBJECTIVES

To examine variation among physician patient-sharing networks in their trajectory of adopting perioperative MRI for breast cancer surgery and compare the characteristics of patients, providers, and mastectomy use in physician networks that had different adoption trajectories.

METHODS AND FINDINGS

Using the Surveillance, Epidemiology, and End Results-Medicare database in 2004-2009, we identified 147 physician patient-sharing networks (caring for 26,886 patients with stage I-III breast cancer). After adjusting for patient clinical risk factors, we calculated risk-adjusted rate of perioperative MRI use for each physician network in 2004-2005, 2006-2007, and 2008-2009, respectively. Based on the risk-adjusted rate, we identified three distinct trajectories of adopting perioperative MRI among physician networks: 1) low adoption (risk-adjusted rate of perioperative MRI increased from 2.8% in 2004-2005 to 14.8% in 2008-2009), 2) medium adoption (8.8% to 45.1%), and 3) high adoption (33.0% to 71.7%). Physician networks in the higher adoption trajectory tended to have a larger proportion of cancer specialists, more patients with high income, and fewer patients who were Black. After adjusting for patients' clinical risk factors, the proportion of patients undergoing mastectomy decreased from 41.1% in 2004-2005 to 38.5% in 2008-2009 among those in physician networks with low MRI adoption, but increased from 27.0% to 31.4% among those in physician networks with high MRI adoption (p = 0.03 for the interaction term between trajectory group and time).

CONCLUSIONS

Physician patient-sharing networks varied in their trajectory of adopting perioperative MRI. These distinct trajectories were associated with the composition of patients and providers in the networks, and had important implications for patterns of mastectomy use.

Cognitive Bias and Therapy Choice in Breast Reconstruction Surgery Decision-Making

BACKGROUND

Understanding how medical experts and their patients process and transfer information is of critical importance for efficient health care provision. Behavioral economics has explored similar credence markets where economic incentives, information asymmetry, and cognitive bias can impact patient and surgeon choice. The aim of the current study is to explore how framing and behavioral bias affect elective restorative surgery decision-making, such as breast reconstruction following cancer treatment.

METHODS

The authors' study uses a cross-sectional survey data set of specialist surgeons (n = 53), breast care nurses (n = 101), and former or current breast cancer patients (n = 689). Data collected include participant demographics, medical history, a battery of cognitive bias tests, and a behavioral framing experiment.

RESULTS

This study finds statistically significant differences in breast reconstruction surgery preference by patients and nurses when decision options are framed in different ways (i.e., positively versus negatively). The authors' analysis of surgeons, nurses, and patients shows no statistically significant difference across eight common forms of cognitive bias. Rather, the authors find that the behavioral biases are prevalent to the same extent in each group. This may indicate that differences in experience and education seem not to mitigate biases that may affect patient choices and medical professional's recommendations. The authors' multivariate analysis identifies patient age (p < 0.0001), body mass index, and self-perceived health (p < 0.05) as negative correlates for choice of implant-based reconstruction.

CONCLUSION

For surgeons, nurses, and patients, the authors find uniform evidence of cognitive bias; more specifically, for patients and nurses, the authors find inconsistency in preference for type of surgical therapy chosen when alternative procedures are framed in different ways (i.e., framing bias).

Breast imaging: Beyond the detection

Breast cancer is a heterogeneous disease nowadays, including different biological subtypes with a variety of possible treatments, which aim to achieve the best outcome in terms of response to therapy and overall survival. In recent years breast imaging has evolved considerably, and the ultimate goal is to predict these strong phenotypic differences noninvasively. Indeed, breast cancer multiparametric studies can highlight not only qualitative imaging parameters, as the presence/absence of a likely malignant finding, but also quantitative parameters, suggesting clinical-pathological features through the evaluation of imaging biomarkers. A further step has been the introduction of artificial intelligence and in particular radiogenomics, that investigates the relationship between breast cancer imaging characteristics and tumor molecular, genomic and proliferation features. In this review, we discuss the main techniques currently in use for breast imaging, their respective fields of use and their technological and diagnostic innovations.

Are we choosing wisely? Drivers of preoperative MRI use in breast cancer patients

INTRODUCTION

Factors contributing to the use of preoperative MRI remain poorly understood.

METHODS

Data from a randomized controlled trial of stage 0-3 breast cancer patients undergoing breast conserving surgery between 2016 and 2018 were analyzed.

RESULTS

Of the 396 patients in this trial, 32.6% had a preoperative MRI. Patient age, race, ethnicity, tumor histology, and use of neoadjuvant therapy were significant predictors of MRI use. On multivariate analysis, younger patients with invasive lobular tumors were more likely to have a preoperative MRI. Rates also varied significantly by individual surgeon (p < 0.001); in particular, female surgeons (39.9% vs. 24.0% for male surgeons, p = 0.001) and those in community practice (58.9% vs. 14.2% for academic, p < 0.001) were more likely to order preoperative MRI. Rates declined over the two years of the study, particularly among female surgeons.

CONCLUSIONS

Preoperative MRI varies with patient age and tumor histology; however, there remains variability by individual surgeon.

Magnetic resonance imaging before breast cancer surgery: results of an observational multicenter international prospective analysis (MIPA)

OBJECTIVES

Preoperative breast magnetic resonance imaging (MRI) can inform surgical planning but might cause overtreatment by increasing the mastectomy rate. The Multicenter International Prospective Analysis (MIPA) study investigated this controversial issue.

METHODS

This observational study enrolled women aged 18-80 years with biopsy-proven breast cancer, who underwent MRI in addition to conventional imaging (mammography and/or breast ultrasonography) or conventional imaging alone before surgery as routine practice at 27 centers. Exclusion criteria included planned neoadjuvant therapy, pregnancy, personal history of any cancer, and distant metastases.

RESULTS

Of 5896 analyzed patients, 2763 (46.9%) had conventional imaging only (noMRI group), and 3133 (53.1%) underwent MRI that was performed for diagnosis, screening, or unknown purposes in 692/3133 women (22.1%), with preoperative intent in 2441/3133 women (77.9%, MRI group). Patients in the MRI group were younger, had denser breasts, more cancers ≥ 20 mm, and a higher rate of invasive lobular histology than patients who underwent conventional imaging alone (p < 0.001 for all comparisons). Mastectomy was planned based on conventional imaging in 22.4% (MRI group) versus 14.4% (noMRI group) (p < 0.001). The additional planned mastectomy rate in the MRI group was 11.3%. The overall performed first- plus second-line mastectomy rate was 36.3% (MRI group) versus 18.0% (noMRI group) (p < 0.001). In women receiving conserving surgery, MRI group had a significantly lower reoperation rate (8.5% versus 11.7%, p < 0.001).

CONCLUSIONS

Clinicians requested breast MRI for women with a higher a priori probability of receiving mastectomy. MRI was associated with 11.3% more mastectomies, and with 3.2% fewer reoperations in the breast conservation subgroup.

KEY POINTS

• In 19% of patients of the MIPA study, breast MRI was performed for screening or diagnostic purposes. • The current patient selection to preoperative breast MRI implies an 11% increase in mastectomies, counterbalanced by a 3% reduction of the reoperation rate. • Data from the MIPA study can support discussion in tumor boards when preoperative MRI is under consideration and should be shared with patients to achieve informed decision-making.

Diagnostic efficacy of contrast-enhanced breast MRI versus X-ray mammography in women with different degrees of breast density

BACKGROUND

Detection of breast cancer in women with high breast densities is a clinical challenge.

PURPOSE

To study the influence of different degrees of breast density on the sensitivity of contrast-enhanced breast magnetic resonance imaging (CE-BMRI) versus X-ray mammography (XRM).

MATERIAL AND METHODS

We performed an additional analysis of two large Phase III clinical trials (G1; G2) which included women with histologically proven breast cancers, called "index cancers." Additional cancers were detected during image reading. We compared the sensitivity of CE-BMRI and XRM in women with different breast densities (ACR A→D; Version 5). For each study, six blinded readers evaluated the images. Results are given as the "Median Reader."

RESULTS

A total of 774 patients were included, 169 had additional cancers. While sensitivity of CE-BMRI for detecting all index cancers was independent of breast density (ACR A→D) (G1: 83%→83%; G2: 91%→91%) the sensitivity of XRM declined (ACR A→D) (G1: 79%→62%; G2: 82%→64%). Thus, the sensitivity difference between both imaging modalities in ACR A breasts of 3% (G1) and 9% (G2) increased to 21% (G1) and 26% (G2) in ACR D breasts. Sensitivity of CE-BMRI for detecting at least one additional cancer increased with increasing breast density (ACR A→D) (G1: 50%→73%, G2: 57%→81%). XRM's sensitivity decreased (G1: 34%→20%) or remained stable (G2: 24%→25%).

CONCLUSION

CE-BMRI showed significantly higher sensitivity compared to XRM.

Preoperative Breast MRI in Women 35 Years of Age and Younger with Breast Cancer: Benefits in Surgical Outcomes by Using Propensity Score Analysis

Background The role of preoperative MRI in women 35 years of age or younger with breast cancer remains controversial. Purpose To determine the association between preoperative MRI and surgical outcomes in women aged 35 years or younger with breast cancer by using propensity score (PS) analysis to investigate the impact of preoperative MRI. Materials and Methods Women 35 years of age or younger diagnosed with breast cancer between 2007 and 2017 who had or had not undergone preoperative breast MRI were retrospectively identified. The MRI detection rate of additional suspicious lesions was analyzed, and changes in surgical management were recorded. Inverse probability weighting (IPW) and PS matching were used to adjust 19 variables and to create a balance between the two groups. Surgical outcomes were compared by using univariable logistic regression. Results Among 964 women (mean age ± standard deviation, 32 years ± 3), 665 (69%) had undergone preoperative MRI (MRI group; mean age, 32 years ± 3) and 299 (31%) had not (no-MRI group; mean age, 32 years ± 3). In the MRI group, additional suspicious lesions were found in 178 of the 665 women (27%), with 88 of those 178 women (49%) having malignant lesions. The surgical management was changed in 99 of the 665 women (15%) due to MRI findings, which was appropriate for 62 of those 99 women (63%). In the IPW analysis, the MRI group showed lower odds of repeat surgery (odds ratio [OR], 0.13; 95% CI: 0.07, 0.21; P < .001) and higher odds of initial mastectomy (OR, 1.62; 95% CI: 1.17, 2.25; P = .004). However, there was no difference in the overall mastectomy rate (OR, 1.24; 95% CI: 0.91, 1.68; P = .17) compared with the no-MRI group. These results were consistent when using the PS matching method. Conclusion Preoperative MRI in young women with breast cancer is useful for detecting additional malignancy and improving surgical outcomes by reducing the repeat surgery rate, with a similar likelihood of overall mastectomy. © RSNA, 2021 Online supplemental material is available for this article.

The Impact of Preoperative Breast Magnetic Resonance Imaging on Surgical Management in Symptomatic Patients With Invasive Lobular Carcinoma

Objective

Due to an insidious proliferative pattern, invasive lobular breast cancer (ILC) often fails to form a defined radiological or palpable lesion and accurate diagnosis remains challenging. This study aimed to determine the value of preoperative magnetic resonance imaging (MRI) for ILC and its impact on surgical outcomes.

Methods

Consecutive symptomatic patients diagnosed with ILC in a tertiary centre over a 9-year period were reviewed. The time from diagnosis until surgery, initial type of surgery/index operation (breast-conserving surgery [BCS]/mastectomy) and the rates of reoperation (re-excision/completion mastectomy) were recorded. Patients were grouped into those who received conventional imaging and preoperative MRI (MR+) and those who received conventional imaging alone (MR-).

Results

There were 218 cases of ILC, and 32.1% (n = 70) had preoperative MRI. Time from diagnosis to surgery was longer in the MR+ than the MR- group (32.5 vs 21.1 days, P < .001) even when adjusting for age and breast density. Initial BCS was performed on 71.4% (n = 50) of MR+ patients and 72.3% (n = 107) of the MR- group. While the rate of completion mastectomy following initial BCS was higher in the MR+ group (30.0%, n = 15 vs 14.0%, n = 15; χ² = 5.63; P = .018), this association was not maintained in multivariable analysis. No difference was recorded in overall (initial and completion) mastectomy rate between the MR+ and MR- group (50.0%, n = 35 vs 37.8%, n = 56; χ² = 2.89; P = .089). Margin re-excision following BCS was comparable between groups (8.0%, n =4, vs 9.3%, n = 10; χ² = 0.076, P = .783) despite the selection bias for borderline conservable cases in the MR+ group. The rate of usage of MRI for ILC cases declined over the study period.

Conclusion

While MRI was associated with minor delays in treatment and did not reduce overall rates of margin re-excision or completion mastectomy, it altered the choice of surgical procedure in almost a quarter of MR+ cases. The benefit of preoperative breast MRI appears to be confined to select (younger, dense breast, borderline conservable) cases in symptomatic ILC.

Utilization of breast MRI and breast MRI-guided biopsy in clinical practice: results of a survey in Québec and France

Background

To investigate the practice regarding breast MRI exams and breast MRI-guided biopsies in two countries with different health care systems, France and Québec. A 12-item questionnaire was distributed online among radiologists from France and Québec, attempting to determine: demographic characteristics and breast MRI diagnostic and MRI-guided practices (indications, workload, availability, and waiting time assessment).

Results

One hundred and seventy radiologists (France, 132 respondents (28.5%); Quebec, 38 respondents (35.2%)) participated in the survey, most of them based in non-academic centers. Thirty-eight percent of Quebec and 2.3% of French radiologists did not perform breast MRI in their daily practice. Nearly 50% of French and Quebec respondents interpreted 1–10 breast MRI exams per week. Decision-making factors of preoperative MRI were similar in both countries (pathology, age, and breast density), with a heavier emphasis placed on the surgeon’s opinion in Quebec (47.8% versus 21.8% (p = 0.009)). Quebec demonstrated a higher waiting time than France (1–2 weeks in 40% versus less than 1 week in 40%). MRI-guided breast biopsies (less than 5 MRI-guided biopsies per week) were being performed by a minority of the respondents (36% in France and 43% in Québec).

Conclusion

Most of radiologists performing breast MRIs work in non-academic institutions in both countries. Waiting time is higher in Quebec, but most of preoperative breast MRIs are performed within 3 weeks in both countries. The surgeon plays an important role in recommending preoperative MRI in Quebec. MRI-guided breast biopsies are not widely available in both countries.

Performance of preoperative breast MRI based on breast cancer molecular subtype

PURPOSE

To assess the performance of preoperative breast MRI biopsy recommendations based on breast cancer molecular subtype.

METHODS

All preoperative breast MRIs at a single academic medical center from May 2010 to March 2014 were identified. Reports were reviewed for biopsy recommendations. All pathology reports were reviewed to determine biopsy recommendation outcomes. Molecular subtypes were defined as Luminal A (ER/PR+ and HER2-), Luminal B (ER/PR+ and HER2+), HER2 (ER-, PR- and HER2+), and Basal (ER-, PR-, and HER2-). Logistic regression assessed the probability of true positive versus false positive biopsy and mastectomy versus lumpectomy.

RESULTS

There were 383 patients included with a molecular subtype distribution of 253 Luminal A, 44 Luminal B, 20 HER2, and 66 Basal. Two hundred and thirteen (56%) patients and 319 sites were recommended for biopsy. Molecular subtype did not influence the recommendation for biopsy (p = 0.69) or the number of biopsy site recommendations (p = 0.30). The positive predictive value for a biopsy recommendation was 42% overall and 46% for Luminal A, 43% for Luminal B, 36% for HER2, and 29% for Basal subtype cancers. The multivariate logistic regression model showed no difference in true positive biopsy rate based on molecular subtype (p = 0.78). Fifty-one percent of patients underwent mastectomy and the multivariate model demonstrated that only a true positive biopsy (odds ratio: 5.3) was associated with higher mastectomy rates.

CONCLUSION

Breast cancer molecular subtype did not influence biopsy recommendations, positive predictive values, or surgical approaches. Only true positive biopsies increased the mastectomy rate.

Solving the preoperative breast MRI conundrum: design and protocol of the MIPA study

Despite its high diagnostic performance, the use of breast MRI in the preoperative setting is controversial. It has the potential for personalized surgical management in breast cancer patients, but two of three randomized controlled trials did not show results in favor of its introduction for assessing the disease extent before surgery. Meta-analyses showed a higher mastectomy rate in women undergoing preoperative MRI compared to those who do not. Nevertheless, preoperative breast MRI is increasingly used and a survey from the American Society of Breast Surgeons showed that 41% of respondents ask for it in daily practice. In this context, a large-scale observational multicenter international prospective analysis (MIPA study) was proposed under the guidance of the European Network for the Assessment of Imaging in Medicine (EuroAIM). The aims were (1) to prospectively and systematically collect data on consecutive women with a newly diagnosed breast cancer, not candidates for neoadjuvant therapy, who are offered or not offered breast MRI before surgery according to local practice; (2) to compare these two groups in terms of surgical and clinical endpoints, adjusting for covariates. The underlying hypotheses are that MRI does not cause additional mastectomies compared to conventional imaging, while reducing the reoperation rate in all or in subgroups of patients. Ninety-six centers applied to a web-based call; 36 were initially selected based on volume and quality standards; 27 were active for enrollment. On November 2018, the target of 7000 enrolled patients was reached. The MIPA study is presently at the analytic phase. Key Points • Breast MRI has a high diagnostic performance but its utility in the preoperative setting is controversial. • A large-scale observational multicenter prospective study was launched to compare women receiving with those not receiving preoperative MRI. • Twenty-seven centers enrolled more than 7000 patients. The study is presently at the analytic phase.

Surgical Outcomes for Ductal Carcinoma in Situ: Impact of Preoperative MRI

Background The role of preoperative MRI for predicting surgical outcomes in patients diagnosed with ductal carcinoma in situ (DCIS) remains uncertain. Purpose To investigate the associations between preoperative MRI and surgical outcomes in DCIS confirmed by using US-guided core-needle biopsy (CNB) and to evaluate clinical-pathologic variables associated with a benefit from MRI. Materials and Methods Women with DCIS confirmed by using US-guided CNB between January 2012 and December 2016 were included in this retrospective study. Propensity score matching using 18 confounding covariates was used to create matched groups with MRI and without MRI, and surgical outcomes were compared. Clinical-pathologic variables were evaluated to determine women who benefited from MRI. Results A total of 541 women (mean age ± standard deviation, 50 years ± 10) were evaluated. Among 430 women who underwent MRI, 67 additional lesions (16%) were depicted, with 25 (37%) of the 67 additional lesions being malignant. Fifty-seven (13%) of the 430 women had a change in surgical plan because of their MRI findings; the change was appropriate for 31 (54%) women. In matched groups, the MRI group was associated with lower odds of positive resection margin (odds ratio [OR], 0.39; 95% confidence interval [CI]: 0.16, 0.93; P = .03) and repeat surgery (OR, 0.33; 95% CI: 0.12, 0.92; P = .03) compared with the non-MRI group. There was no difference in likelihood of initial mastectomy (OR, 1.2; 95% CI: 0.7, 2.0; P = .59) and overall mastectomy (OR, 0.93; 95% CI: 0.5, 1.6; P = .79). In the MRI group, low nuclear grade (90% [28 of 31] vs 69% [275 of 399]; P = .01), progesterone receptor positivity (81% [25 of 31] vs 61% [244 of 399]; P = .03), and human epidermal growth factor receptor 2 negativity (90% [28 of 31] vs 68% [270 of 399]; P = .01) were associated with a benefit from MRI versus no MRI. Conclusion Preoperative MRI depicted additional malignancy and reduced positive surgical margins and repeat surgery for ductal carcinoma in situ confirmed at US-guided biopsy without a higher mastectomy rate. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Pinker in this issue.

Breast Cancer Radiogenomics: Current Status and Future Directions

Radiogenomics is an area of research that aims to identify associations between imaging phenotypes ("radio-") and tumor genome ("-genomics"). Breast cancer radiogenomics research in particular has been an especially prolific area of investigation in recent years as evidenced by the wide number and variety of publications and conferences presentations. To date, research has primarily been focused on dynamic contrast enhanced pre-operative breast MRI and breast cancer molecular subtypes, but investigations have extended to all breast imaging modalities as well as multiple additional genetic markers including those that are commercially available. Furthermore, both human and computer-extracted features as well as deep learning techniques have been explored. This review will summarize the specific imaging modalities used in radiogenomics analysis, describe the methods of extracting imaging features, and present the types of genomics, molecular, and related information used for analysis. Finally, the limitations and future directions of breast cancer radiogenomics research will be discussed.

Prognostic significance of preoperative MRI findings in young patients with breast cancer

The objective is to evaluate the prognostic value of preoperative magnetic resonance imaging (MRI) findings in breast cancer patients aged less than 40 years. This retrospective, single-center study evaluated 92 women aged <40 years who received a diagnosis of invasive breast carcinoma between 2008 and 2012. These patients underwent a breast MRI before treatment and follow-up at the same institution. Kaplan-Meier survival curves were used to analyze overall survival, with the log-rank test used to compare different groups. Cox regression analysis was used to estimate hazard ratios (HRs) with 95% confidence interval (95% CI) values. The mean age of the patients was 34 years (range: 25–39 years) and the mean tumor size was 3.9 cm in maximal dimension (range: 0.7–10.5 cm). Recurrence was observed in 21 (22.8%) patients and 15 (16.3%) patients did not survive during a mean follow-up period of 5.4 ± 1.9 years. MRI findings associated with worse overall survival included tumor size >5 cm (HR:5.404; 95% CI:1.922–15.198; p = 0.017), presence of non-mass enhancement (HR:3.730; 95% CI:1.274–10.922; p = 0.016) and multifocal tumor (HR:3.618; 95% CI:1.151–11.369; p = 0.028). Inconclusion, MRI findings that are suggestive of more extensive disease were associated with worse overall survival in young breast cancer patients.

Artificial Intelligence for Breast MRI in 2008-2018: A Systematic Mapping Review

OBJECTIVE

The purpose of this study is to review literature from the past decade on applications of artificial intelligence (AI) to breast MRI.

MATERIALS AND METHODS

In June 2018, a systematic search of the literature was performed to identify articles on the use of AI in breast MRI. For each article identified, the surname of the first author, year of publication, journal of publication, Web of Science Core Collection journal category, country of affiliation of the first author, study design, dataset, study aim(s), AI methods used, and, when available, diagnostic performance were recorded.

RESULTS

Sixty-seven studies, 58 (87%) of which had a retrospective design, were analyzed. When journal categories were considered, 36% of articles were identified as being included in the radiology and imaging journal category. Contrast-enhanced sequences were used for most AI applications (n = 50; 75%) and, on occasion, were combined with other MRI sequences (n = 8; 12%). Four main clinical aims were addressed: breast lesion classification (n = 36; 54%), image processing (n = 14; 21%), prognostic imaging (n = 9; 13%), and response to neoadjuvant therapy (n = 8; 12%). Artificial neural networks, support vector machines, and clustering were the most frequently used algorithms, accounting for 66%. The performance achieved and the most frequently used techniques were then analyzed according to specific clinical aims. Supervised learning algorithms were primarily used for lesion characterization, with the AUC value from ROC analysis ranging from 0.74 to 0.98 (median, 0.87) and with that from prognostic imaging ranging from 0.62 to 0.88 (median, 0.80), whereas unsupervised learning was mainly used for image processing purposes.

CONCLUSION

Interest in the application of advanced AI methods to breast MRI is growing worldwide. Although this growth is encouraging, the current performance of AI applications in breast MRI means that such applications are still far from being incorporated into clinical practice.