Preoperative Breast Magnetic Resonance Imaging and Contralateral Breast Cancer Occurrence Among Older Women With Breast Cancer

Breast Magnetic Resonance Imaging for Preoperative Evaluation of Breast Cancer: A Systematic Review and Meta-Analysis

Purpose: Preoperative breast magnetic resonance imaging (MRI) is known to detect additional cancers that are occult on mammography and ultrasound. There is debate as to whether these additional lesions affect clinical outcomes. The objective of this systematic review was to summarize the evidence on whether additional information on disease extent obtained with preoperative breast MRI in patients with newly diagnosed breast cancer affects surgical management, rates of recurrence, survival, re-excision, and early detection of bilateral cancer. Methods: Embase, MEDLINE, and Cochrane Central Register of Controlled Trials were searched until January 2021 (partial update July 2022) for studies comparing outcomes with versus without pre-operative MRI. Included were both randomized controlled trials and other comparative studies provided MRI and control groups had equivalent disease and patient characteristics or methods such as multivariable analysis or propensity score matching were used to control potential confounders. Results: The search resulted in 26,399 citations, of which 8 randomized control trials, 1 prospective cohort study, and 42 retrospective studies met the inclusion criteria. Use of MRI resulted in decreased rates of reoperations (OR = 0.73, 95% CI = 0.63 to 0.85), re-excisions (OR = 0.63, 95% CI = 0.45 to 0.89), and recurrence (HR = 0.77, 95% CI = 0.65 to 0.90). Increased detection of synchronous contralateral breast cancers led to a reduction in metachronous contralateral breast cancer (HR = 0.71, 95% CI = 0.59 to 0.85). Hazard ratios for recurrence-free and overall survival were 0.77 (95% CI = 0.53 to 1.12) and 0.89 (95% CI = 0.74 to 1.07). Conclusion: This systematic review indicates substantial benefits of pre-operative breast MRI in decreasing reoperations and recurrence.

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.

Breast Magnetic Resonance Imaging for Patients With Newly Diagnosed Breast Cancer: A Review

Despite the high sensitivity and widespread use of preoperative magnetic resonance imaging (MRI), the American Cancer Society and the National Comprehensive Cancer Network guidelines do not recommend the routine use of preoperative MRI owing to the conflicting results and lack of clear benefit to the surgical outcome (reoperation and mastectomy) and long-term clinical outcomes (local recurrence and metachronous contralateral breast cancer). Preoperative MRI detects additional cancers that are occult at mammography and ultrasound but increases the rate of mastectomy. Concerns about overdiagnosis and overtreatment of preoperative MRI might be mitigated by adjusting the confounding factors when conducting studies, using the state-of-the-art image-guided biopsy technique, applying the radiologists’ cumulative experiences in interpreting MRI findings, and performing multiple lumpectomies in patients with multicentric cancer. Among the various imaging methods, dynamic contrast-enhanced MRI has the highest accuracy in predicting pathologic complete response after neoadjuvant chemotherapy. Prospective trials aimed at applying the MRI information to the de-escalation of surgical or radiation treatments are underway. In this review, current studies on the clinical outcomes of preoperative breast MRI are updated, and circumstances in which MRI may be useful for surgical planning are discussed.

A simplified scoring protocol to improve diagnostic accuracy with the breast imaging reporting and data system in breast magnetic resonance imaging

BACKGROUND

The breast imaging reporting and data system (BI-RADS) lexicon provides a standardized terminology for describing leision characteristics but does not provide defined rules for converting specific imaging features into diagnostic categories. The inter-reader agreement of the BI-RADS is moderate. In this study, we explored the use of a simplified protocol and scoring system for BI-RADS categorization which integrates the morphologic features (MF), kinetic time-intensity curve (TIC), and apparent diffusion coefficient (ADC) values with equal weights, with a view to providing a convenient and practical method for breast magnetic resonance imaging (MRI) and improving the inter-reader agreement and diagnostic performance of BI-RADS.

METHODS

This cross-sectional, retrospective, single-center study included 879 patients with 898 histopathologically verified lesions who underwent an MRI scan on a 3.0 Tesla GE Discovery 750 MRI scanner between January 1, 2017, and June 30, 2020. The BI-RADS categorization of the studied lesions was assessed according to the sum of the assigned scores (the presence of malignant MF, lower ADC, and suspicious TIC each warranted a score of +1). Total scores of +2 and +3 were classified as category 5, scores of +1 were classified as category 4, and scores of +0 but with other lesions of interest were classified as category 3. The receiver operating characteristic (ROC) curves were plotted, and the sensitivity, specificity, and accuracy of this categorization were investigated to assess its efficacy and its consistency with pathology.

RESULTS

There were 472 malignant, 104 risk, and 322 benign lesions. Our simplified scoring protocol had high diagnostic accuracy, with an area under curve (AUC) value of 0.896. In terms of the borderline effect of pathological risk and category 4 lesions, our results showed that when risk lesions were classified together with malignant ones, the AUC value improved (0.876 vs. 0.844 and 0.909 vs. 0.900). When category 4 and 5 lesions were classified as malignant, the specificity, accuracy, and AUC value decreased (82.3% vs. 93.2%, 89.3% vs. 90.2%, and 0.876 vs. 0.909, respectively). Therefore, to improve the diagnostic accuracy of the protocol for BI-RADS categorization, only category 5 lesions should be considered to be malignant.

CONCLUSIONS

Our simplified scoring protocol that integrates MF, TIC, and ADC values with equal weights for BI-RADS categorization could improve both the diagnostic performance of the protocol for BI-RADS categorization in clinical practice and the understanding of the benign-risk-malignant breast diseases.

Contralateral Breast Screening with Preoperative MRI: Long-Term Outcomes for Newly Diagnosed Breast Cancer

Background The diagnostic value of screening the contralateral breast with MRI in patients with newly diagnosed breast cancer is poorly understood. Purpose To assess the impact of MRI for screening the contralateral breast on long-term outcomes in patients with newly diagnosed breast cancer and to determine whether subgroups with unfavorable prognoses would benefit from MRI in terms of survival. Materials and Methods Data on consecutive patients with newly diagnosed breast cancer seen from January 2008 to December 2010 were reviewed retrospectively. Patients with neoadjuvant chemotherapy, previous breast cancer, distant metastasis, absence of contralateral mammography at diagnosis, and no planned surgical treatment were excluded. Groups that did and did not undergo preoperative MRI were compared. Survival analysis was performed using the Kaplan-Meier method for propensity score-matched groups to estimate cause-specific survival (CSS) and overall survival (OS). A marginal Cox proportional hazards model was used to evaluate association of MRI and clinicopathologic variables with OS. Results Of 1846 patients, 1199 fulfilled the inclusion criteria. Median follow-up time was 10 years (range, 0-14 years). The 2:1 matched sample comprised 705 patients (470 in the MRI group and 235 in the no-MRI group); median ages at surgery were 59 years (range, 31-87 years) and 64 years (range, 37-92 years), respectively. MRI depicted contralateral synchronous disease more frequently (27 of 470 patients [5.7%] vs five of 235 patients [2.1%]; P = .047) and was associated with a higher OS (hazard ratio [HR], 2.51; 95% CI: 1.25, 5.06; P = .01). No differences were observed between groups in metachronous disease rate (MRI group: 21 of 470 patients [4.5%]; no-MRI group: 10 of 235 patients [4.3%]; P > .99) or CSS (HR, 1.34; 95% CI: 0.56, 3.21; P = .51). MRI benefit was greater in patients with larger tumor sizes (>2 cm) (HR, 2.58; 95% CI: 1.11, 5.99; P = .03) and histologic grade III tumors (HR, 2.94; 95% CI: 1.18, 7.32; P = .02). Conclusion Routine MRI screening of the contralateral breast after first diagnosis of breast cancer improved overall survival; the most pronounced benefit was found in patients with larger primary tumor size and primary tumors of histologic grade III. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Taourel in this issue.

Characterizing and quantifying low-value diagnostic imaging internationally: a scoping review

BACKGROUND

Inappropriate and wasteful use of health care resources is a common problem, constituting 10-34% of health services spending in the western world. Even though diagnostic imaging is vital for identifying correct diagnoses and administrating the right treatment, low-value imaging-in which the diagnostic test confers little to no clinical benefit-is common and contributes to inappropriate and wasteful use of health care resources. There is a lack of knowledge on the types and extent of low-value imaging. Accordingly, the objective of this study was to identify, characterize, and quantify the extent of low-value diagnostic imaging examinations for adults and children.

METHODS

A scoping review of the published literature was performed. Medline-Ovid, Embase-Ovid, Scopus, and Cochrane Library were searched for studies published from 2010 to September 2020. The search strategy was built from medical subject headings (Mesh) for Diagnostic imaging/Radiology OR Health service misuse/Medical overuse OR Procedures and Techniques Utilization/Facilities and Services Utilization. Articles in English, German, Dutch, Swedish, Danish, or Norwegian were included.

RESULTS

A total of 39,986 records were identified and, of these, 370 studies were included in the final synthesis. Eighty-four low-value imaging examinations were identified. Imaging of atraumatic pain, routine imaging in minor head injury, trauma, thrombosis, urolithiasis, after thoracic interventions, fracture follow-up and cancer staging/follow-up were the most frequently identified low-value imaging examinations. The proportion of low-value imaging varied between 2 and 100% inappropriate or unnecessary examinations.

CONCLUSIONS

A comprehensive list of identified low-value radiological examinations for both adults and children are presented. Future research should focus on reasons for low-value imaging utilization and interventions to reduce the use of low-value imaging internationally.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42020208072.

Impact of Preoperative Magnetic Resonance Imaging on Surgical Outcomes in Women with Invasive Breast Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Currently, whether magnetic resonance imaging (MRI) should be routinely applied to patients with breast cancer before surgery remains controversial. A pooled analysis of the association between preoperative MRI and surgical outcomes in female patients with newly diagnosed invasive breast cancer was conducted to provide evidence-based medicine for clinical practice.

METHODS

Three independent researchers searched the following databases: PubMed, Medline, Embase, Ovid, Cochrane Library, and Web of Science from inception to April 2022. Literature was included and excluded according to Cochrane's principles. The basic information from eligible documents was extracted. Systematic evaluation and meta-analysis were performed, and the odds ratio (OR) was analyzed by the random-effect model. The quality of the literature was assessed using the modified Jadad scale and the Newcastle-Ottawa (NOS) mean scale.

RESULTS

A total of 19 studies were included, including 4 randomized controlled trials and 15 observational comparative studies. Among them, most studies were not limited to a specific pathological type, with the exception of 3 that were limited to invasive lobular carcinoma. The results showed that preoperative MRI examination would significantly reduce the reoperation rate (OR = 0.77, P=0.02) and increase the mastectomy rate (OR = 1.36, P=0.001). In comparison, preoperative MRI did not significantly affect the rate of secondary mastectomy (OR = 0.77, P=0.02), the rate of positive margin (OR = 1.08, P=0.66), the rate of mastectomy (OR = 1.00, P < 0.05), and reoperations (OR = 0.65, P=0.19) in the subgroup analysis of patients with invasive lobular carcinoma.

CONCLUSION

Available evidence suggests that preoperative MRI examination increases the rate of mastectomy and reduces the rate of reoperations. The results indicate that preoperative MRI examination has the potential to benefit patients with breast cancer, but more high-quality studies are needed for confirmation.

Impact of pre-operative breast magnetic resonance imaging on contralateral synchronous and metachronous breast cancer detection-A case control comparison study with 1468 primary operable breast cancer patients with mean follow-up of 102 months

Background

Women with unilateral breast cancer are at an increased risk for the development of contralateral breast cancers. We hypothesis that combined breast MRI would detect more contralateral synchronous breast cancer than conventional imaging alone, and resulted in less contralateral metachronous breast cancer during follow-up.

Methods

We retrospectively collected two groups of breast cancer patients diagnosed from 2009 to 2013 for evaluating the effectiveness and value of adding pre-operative breast MRI to conventional breast images (mammography and sonography) for detection of contralateral synchronous breast cancer. The new metachronous contralateral breast cancer diagnosed during follow-up was prospectively evaluated and compared.

Results

Group A (n = 733) comprised patients who underwent conventional preoperative imaging and group B (n = 735) combined with MRI were enrolled and compared. Seventy (9.5%) of the group B patients were found to have contralateral lesions detected by breast MRI, and 65.7% of these lesions only visible with MRI. The positive predictive value of breast MRI detected contralateral lesions was 48.8%. With the addition of breast MRI to conventional imaging studies, more surgical excisions were performed in contralateral breasts (6% (44/735) versus 1.4% (10/733), P< 0.01), more synchronous contralateral breast cancer detected (2.9% (21/735) versus 1.1% (8/733), P = 0.02), and resulted in numerical less (2.2% (16/714) versus 3% (22/725), p = 0.3) metachronous contralateral breast cancer during a mean follow-up of 102 months.

Conclusions

Our study provides useful estimates of the pre-operative breast MRI for the increased detection of contralateral synchronous breast cancer and less subsequent contralateral metachronous breast cancer.

The selective use of preoperative MRI in the staging of breast cancer: a single-institution experience

INTRODUCTION

Routine use of preoperative breast magnetic resonance imaging (MRI) for loco-regional staging of breast cancer remains controversial. At Counties Manukau District Health Board (CMDHB), preoperative breast MRI is used selectively within a multidisciplinary setting. The purpose of this study is to determine the accuracy of selective use of preoperative MRI in staging loco-regional disease and how it has impacted our clinical practice.

METHODS

Patients who received preoperative MRI at CMDHB between October 2015 and October 2018 were identified on a prospective database. The decision to offer MRI was made by multidisciplinary consensus. Patient data were collected retrospectively from clinical, imaging and histology records. The accuracy of MRI was determined by comparing it against histology as gold standard, and its potential contribution to treatment decisions and treatment delay was determined by clinical record review.

RESULTS

Ninety-two patients received preoperative MRI. Additional foci of cancer were identified in ten patients (11%). Sixteen patients (17%) required additional biopsies. In fourteen patients (15%), MRI identified more extensive disease than conventional imaging prompting a change of surgical management. This 'upstaging' was confirmed histologically in twelve (13%). In one (1%) patient, MRI incorrectly 'downstaged' disease, but it did not alter the management. No patients experienced a delay in treatment due to MRI.

CONCLUSION

A selective, considered use of preoperative MRI within a multidisciplinary setting at our local institution results in more biopsies but with an acceptable risk-benefit ratio. It provides accurate staging to aid treatment decisions without resulting in a delay in treatment.

Association Between Degrees of Separation in Physician Networks and Surgeons' Use of Perioperative Breast Magnetic Resonance Imaging

BACKGROUND

Perioperative magnetic resonance imaging (MRI) is frequently used in breast cancer despite unproven benefits. It is unclear whether surgeons' use of breast MRI is associated with the practices of other surgeons to whom they are connected through shared patients.

METHODS

We conducted a retrospective study using Medicare data to identify physicians providing breast cancer care during 2007-2009 and grouped them into patient-sharing networks. Physician pairs were classified according to their "degree of separation" based on patient-sharing (eg, physician pairs that care for the same patients were separated by 1 degree; pairs that both share patients with another physician but not with each other were separated by 2 degrees). We assessed the association between the MRI use of a surgeon and the practice patterns of surgical colleagues by comparing MRI use in the observed networks with networks with randomly shuffled rates of MRI utilization.

RESULTS

Of the 15,273 patients who underwent surgery during the study period, 28.8% received perioperative MRI. These patients received care from 1806 surgeons in 60 patient-sharing networks; 55.1% of surgeons used MRI. A surgeon was 24.5% more likely to use MRI if they were directly connected to a surgeon who used MRI. This effect decreased to 16.3% for pairs of surgeons separated by 2 degrees, and 0.8% at the third degree of separation.

CONCLUSIONS

Surgeons' use of perioperative breast MRI is associated with the practice of surgeons connected to them through patient-sharing; the strength of this association attenuates as the degree of separation increases.

Diffusional kurtosis imaging for differentiation of additional suspicious lesions on preoperative breast MRI of patients with known breast cancer

PURPOSE

To investigate the potential of diffusional kurtosis imaging (DKI) and conventional diffusion-weighted imaging (DWI) in the evaluation of additional suspicious lesions at preoperative breast magnetic resonance imaging (MRI) in patients with breast cancer.

MATERIALS AND METHODS

Fifty-three additional suspicious lesions in 45 patients with breast cancer, which were detected on preoperative breast MRI, were examined with a 3-T MR system. DKI and DWI data were obtained using a spin-echo single-shot echo-planar imaging sequence with b-values of 0, 50, 600, 1000, and 3000 s/mm². Histogram parameters (mean, standard deviation, minimum, maximum, 10th, 25th, 50th, 75th, 90th percentiles, kurtosis, skewness and entropy) of ADC from DWI and diffusivity (D), kurtosis (K) from DKI were calculated after postprocessing. Parameters were compared between benign vs. ductal carcinoma in situ (DCIS) vs. invasive breast lesions and diagnostic performances were evaluated by receiver operating characteristic (ROC) analysis. Correlation between the mean values of D and K was analyzed according to lesion type.

RESULTS

Multiple histogram parameters of D (mean, 25th, 50th percentile, 75th percentile, and entropy) differed between benign and invasive breast lesions (all P < 0.005), but none differed between benign vs. DCIS. D-90th percentile differed between DCIS vs. invasive cancer (P = 0.040). K-10th percentile differed between benign vs. DCIS (P = 0.015). ADC-75th percentile differed between benign vs. invasive cancer and ADC-75th percentile, ADC-90th percentile differed between DCIS vs. invasive cancer, respectively (all P < 0.005). ROC curve analysis showed high specificity for discrimination between benign and invasive cancer. D-mean and K-mean showed strong correlation in benign (r_s = -0.813) and invasive lesions (r_s = -0.853), but no significant correlation in DCIS.

CONCLUSION

DKI may aid in the differentiation of additional suspicious lesions at preoperative breast MRI. Both ADC and DKI may have lower potential in differentiating DCIS from benign lesions.

Surgeon peer network characteristics and adoption of new imaging techniques in breast cancer: A study of perioperative MRI

Background

Perioperative MRI has disseminated into breast cancer practice despite equivocal evidence. We used a novel social network approach to assess the relationship between the characteristics of surgeons’ patient‐sharing networks and subsequent use of MRI.

Methods

We identified a cohort of female patients with stage 0‐III breast cancer from the Surveillance, Epidemiology, and End Results (SEER)‐Medicare database. We used claims data from these patients and non‐cancer patients from the 5% Medicare sample to identify peer groups of physicians who shared patients during 2004‐2006 (T1). We used a multivariable hierarchical model to identify peer group characteristics associated with uptake of MRI in T2 (2007‐2009) by surgeons who had not used MRI in T1.

Results

Our T1 sample included 15 149 patients with breast cancer, treated by 2439 surgeons in 390 physician groups. During T1, 9.1% of patients received an MRI; the use of MRI varied from 0% to 100% (IQR 0%, 8.5%) across peer groups. After adjusting for clinical characteristics, patients treated by surgeons in groups with a higher proportion of primary care physicians (PCPs) in T1 were less likely to receive MRI in T2 (OR = 0.81 for 10% increase in PCPs, 95% CI = 0.71, 0.93). Surgeon transitivity (ie, clustering of surgeons) was significantly associated with MRI receipt (P = 0.013); patients whose surgeons were in groups with higher transitivity in T1 were more likely to receive MRI in T2 (OR = 1.29 for 10% increase in clustering, 95% CI = 1.06, 1.58).

Conclusion

The characteristics of a surgeon's peer network are associated with their patients’ subsequent receipt of perioperative MRI.

Associations of preoperative breast magnetic resonance imaging with subsequent mastectomy and breast cancer mortality

PURPOSE

To examine associations between pre-operative magnetic resonance imaging (MRI) use and clinical outcomes among women undergoing breast-conserving surgery (BCS) with or without radiotherapy for early-stage breast cancer.

METHODS

We identified women from the Surveillance, Epidemiology, and End Results-Medicare dataset aged 67-94 diagnosed during 2004-2010 with stage I/II breast cancer who received BCS. We compared subsequent mastectomy and breast cancer mortality with versus without pre-operative MRI, using Cox regression and competing risks models. We further stratified by receipt of radiotherapy for subgroup analyses.

RESULTS

Our sample consisted of 24,379 beneficiaries, 4691 (19.2%) of whom received pre-operative MRI. Adjusted rates of subsequent mastectomy and breast cancer mortality were not significantly different with and without MRI: 3.2 versus 4.1 per 1000 person-years [adjusted hazard ratio (AHR) 0.92; 95% confidence interval (CI) 0.70-1.19] and 5.3 versus 8.7 per 1000 person-years (AHR 0.89; 95% CI 0.73-1.08), respectively. In subgroup analyses, women receiving BCS plus radiotherapy had similar rates of subsequent mastectomy (AHR 1.17; 95% CI 0.84-1.61) and breast cancer mortality (AHR 1.00; 95% CI 0.80-1.24) with versus without MRI. However, among women receiving BCS alone, MRI use was associated with lower risks of subsequent mastectomy (AHR 0.60; 95% CI 0.37-0.98) and breast cancer mortality (AHR 0.57; 95% CI 0.36-0.92).

CONCLUSIONS

Pre-operative MRI was associated with improved outcomes among older women with breast cancer receiving BCS alone, but not among those receiving BCS plus radiotherapy. Further research is needed to identify appropriate settings for which MRI may be helpful.

Predictive value of breast magnetic resonance imaging in detecting mammographically occult contralateral breast cancer: Can we target women more likely to have contralateral breast cancer?

BACKGROUND AND OBJECTIVES

Preoperative breast magnetic resonance imaging (B-MRI) staging in newly diagnosed breast cancer increases detection of synchronous contralateral findings, but may result in false-positive outcomes. This study objective was to identify women more likely of having mammographically occult, MRI detected contralateral breast cancer (CBC).

METHODS

We performed a retrospective review of patients who had preoperative B-MRI prior to surgery from 2010 to 2015 and collected patient imaging and clinicopathologic data. Multivariate logistic regression was used to identify predictors of CBC.

RESULTS

MRI resulted in contralateral findings in 201 of 1894 patients (10.6%). Overall 3.2% (60 of 1894) had synchronous CBC detected on B-MRI. The majority of CBCs (n = 60) were stage 0 or IA (85.0%), hormone receptor positive (94.9%), human epidermal growth factor receptor 2 (HER2/neu) negative (89.7%), and low/intermediate pathological grade (87.2%). Women more likely to have CBC were older (P < .001), had lobular index cancer (P = .03), and estrogen receptor (ER)+ (P = .027) or progesterone receptor (PR)+ (P = .002) tumors. On multivariate analysis (receiver operating characteristic curve area = 0.75), PR + status (P = .022), and older age (P = .004) were predictive of CBC.

CONCLUSIONS

Preoperative MRI is most effective in detecting early stage, hormone receptor-positive CBC in older women.

MRI for the Staging and Evaluation of Response to Therapy in Breast Cancer

Breast magnetic resonance imaging (MRI) is the most sensitive of the available imaging modalities to characterize breast cancer. Breast MRI has gained clinical acceptance for screening high-risk patients, but its role in the preoperative imaging of breast cancer patients remains controversial. This review focuses on the current indications for staging breast MRI, the evidence for and against the role of breast MRI in the preoperative staging workup, and the evaluation of treatment response of breast cancer patients.

Frequency and characteristics of contralateral breast abnormalities following recall at screening mammography

PURPOSE

To determine the frequency and characteristics of contralateral, non-recalled breast abnormalities following recall at screening mammography.

METHODS

We included a series of 130,338 screening mammograms performed between 1 January 2014 and 1 January 2016. During the 1-year follow-up, clinical data were collected for all recalls. Screening outcome was determined for recalled women with or without evaluation of contralateral breast abnormalities.

RESULTS

Of 3,995 recalls (recall rate 3.1%), 129 women (3.2%) underwent assessment of a contralateral, non-recalled breast abnormality. Most lesions were detected at clinical mammography and/or breast tomosynthesis (101 women, 78.3%). The biopsy rate was similar for recalled lesions and contralateral, non-recalled lesions, but the positive predictive value of biopsy was higher for recalled lesions (p = 0.01). A comparable proportion of the recalled lesions and contralateral, non-recalled lesions were malignant (p = 0.1). The proportion of ductal carcinoma in situ was similar for both groups, as well as invasive cancer characteristics and type of surgical treatment.

CONCLUSIONS

About 3% of recalled women underwent evaluation of contralateral, non-recalled breast lesions. Evaluation of the contralateral breast after recall is important as we found that 15.5% of contralateral, non-recalled lesions were malignant. Contralateral cancers and screen-detected cancers show similar characteristics, stage and surgical treatment.

KEY POINTS

• 3% of recalled women underwent evaluation of contralateral, non-recalled lesions • One out of seven contralateral, non-recalled lesions was malignant • A contralateral cancer was diagnosed in 0.5% of recalls • Screen-detected cancers and non-recalled, contralateral cancers showed similar histological characteristics • Tumour stage and surgical treatment were similar for both groups.

Mammography screening: A major issue in medicine

Breast cancer mortality is declining in most high-income countries. The role of mammography screening in these declines is much debated. Screening impacts cancer mortality through decreasing the incidence of number of advanced cancers with poor prognosis, while therapies and patient management impact cancer mortality through decreasing the fatality of cancers. The effectiveness of cancer screening is the ability of a screening method to curb the incidence of advanced cancers in populations. Methods for evaluating cancer screening effectiveness are based on the monitoring of age-adjusted incidence rates of advanced cancers that should decrease after the introduction of screening. Likewise, cancer-specific mortality rates should decline more rapidly in areas with screening than in areas without or with lower levels of screening but where patient management is similar. These two criteria have provided evidence that screening for colorectal and cervical cancer contributes to decreasing the mortality associated with these two cancers. In contrast, screening for neuroblastoma in children was discontinued in the early 2000s because these two criteria were not met. In addition, overdiagnosis - i.e. the detection of non-progressing occult neuroblastoma that would not have been life-threatening during the subject's lifetime - is a major undesirable consequence of screening. Accumulating epidemiological data show that in populations where mammography screening has been widespread for a long time, there has been no or only a modest decline in the incidence of advanced cancers, including that of de novo metastatic (stage IV) cancers at diagnosis. Moreover, breast cancer mortality reductions are similar in areas with early introduction and high penetration of screening and in areas with late introduction and low penetration of screening. Overdiagnosis is commonplace, representing 20% or more of all breast cancers among women invited to screening and 30-50% of screen-detected cancers. Overdiagnosis leads to overtreatment and inflicts considerable physical, psychological and economic harm on many women. Overdiagnosis has also exerted considerable disruptive effects on the interpretation of clinical outcomes expressed in percentages (instead of rates) or as overall survival (instead of mortality rates or stage-specific survival). Rates of radical mastectomies have not decreased following the introduction of screening and keep rising in some countries (e.g. the United States of America (USA)). Hence, the epidemiological picture of mammography screening closely resembles that of screening for neuroblastoma. Reappraisals of Swedish mammography trials demonstrate that the design and statistical analysis of these trials were different from those of all trials on screening for cancers other than breast cancer. We found compelling indications that these trials overestimated reductions in breast cancer mortality associated with screening, in part because of the statistical analyses themselves, in part because of improved therapies and underreporting of breast cancer as the underlying cause of death in screening groups. In this regard, Swedish trials should publish the stage-specific breast cancer mortality rates for the screening and control groups separately. Results of the Greater New York Health Insurance Plan trial are biased because of the underreporting of breast cancer cases and deaths that occurred in women who did not participate in screening. After 17 years of follow-up, the United Kingdom (UK) Age Trial showed no benefit from mammography screening starting at age 39-41. Until around 2005, most proponents of breast screening backed the monitoring of changes in advanced cancer incidence and comparative studies on breast cancer mortality for the evaluation of breast screening effectiveness. However, in an attempt to mitigate the contradictions between results of mammography trials and population data, breast-screening proponents have elected to change the criteria for the evaluation of cancer screening effectiveness, giving precedence to incidence-based mortality (IBM) and case-control studies. But practically all IBM studies on mammography screening have a strong ecological component in their design. The two IBM studies done in Norway that meet all methodological requirements do not document significant reductions in breast cancer mortality associated with mammography screening. Because of their propensity to exaggerate the health benefits of screening, case-control studies may demonstrate that mammography screening could reduce the risk of death from diseases other than breast cancer. Numerous statistical model approaches have been conducted for estimating the contributions of screening and of patient management to reductions in breast cancer mortality. Unverified assumptions are needed for running these models. For instance, many models assume that if screening had not occurred, the majority of screen-detected asymptomatic cancers would have progressed to symptomatic advanced cancers. This assumption is not grounded in evidence because a large proportion of screen-detected breast cancers represent overdiagnosis and hence non-progressing tumours. The accumulation of population data in well-screened populations diminishes the relevance of model approaches. The comparison of the performance of different screening modalities - e.g. mammography, digital mammography, ultrasonography, magnetic resonance imaging (MRI), three-dimensional tomosynthesis (TDT) - concentrates on detection rates, which is the ability of a technique to detect more cancers than other techniques. However, a greater detection rate tells little about the capacity to prevent interval and advanced cancers and could just reflect additional overdiagnosis. Studies based on the incidence of advanced cancers and on the evaluation of overdiagnosis should be conducted before marketing new breast-imaging technologies. Women at high risk of breast cancer (i.e. 30% lifetime risk and more), such as women with BRCA1/2 mutations, require a close breast surveillance. MRI is the preferred imaging method until more radical risk-reduction options are eventually adopted. For women with an intermediate risk of breast cancer (i.e. 10-29% lifetime risk), including women with extremely dense breast at mammography, there is no evidence that more frequent mammography screening or screening with other modalities actually reduces the risk of breast cancer death. A plethora of epidemiological data shows that, since 1985, progress in the management of breast cancer patients has led to marked reductions in stage-specific breast cancer mortality, even for patients with disseminated disease (i.e. stage IV cancer) at diagnosis. In contrast, the epidemiological data point to a marginal contribution of mammography screening in the decline in breast cancer mortality. Moreover, the more effective the treatments, the less favourable are the harm-benefit balance of screening mammography. New, effective methods for breast screening are needed, as well as research on risk-based screening strategies.

Clinical and Pathologic Features of Clinically Occult Synchronous Bilateral Breast Cancers

PURPOSE

To investigate clinicopathologic breast cancer characteristics associated with the identification of synchronous bilateral breast cancer (SBBC) on dynamic contrast-enhanced breast magnetic resonance imaging.

METHODS

We performed a retrospective review of 311 consecutive patients newly diagnosed with breast cancer who underwent diagnostic mammography, ultrasonography, and dynamic contrast-enhanced breast magnetic resonance imaging (DCE-MRI) at our institution. Tumor histology, grade, biomarker status (estrogen receptor, progesterone receptor, and HER2), TNM staging, and unifocal or multifocal/multicentric status were compared between the index tumors in the unilateral disease and the SBBC groups, as well as between the index tumors in the unilateral disease group and the synchronous contralateral tumors (SCT) in the SBBC group, using the Fisher exact test.

RESULTS

A total of 326 cancers in 311 patients were reviewed. Fifteen (4.8%) patients were diagnosed with SBBC. The index tumors in patients with SBBC were more frequently lower T stage (p = 0.007), lower grade (p = 0.04), and multifocal/multicentric (p = 0.004) compared with the index tumors in the unilateral group. Biomarkers, N status, and M status did not significantly differ between the index tumors in both groups.

CONCLUSIONS

SBBC was more likely to be identified in women with lower T stage, lower tumor grade and multifocal/multicentric tumors. Multimodality imaging including DCE-MRI is essential in detection and diagnosis of SBBC.

The Impact of Social Contagion on Physician Adoption of Advanced Imaging Tests in Breast Cancer

Background

Magnetic resonance imaging (MRI) and positron emission tomography (PET) scans are widely used in breast cancer practice despite unproven benefits. We examined the extent to which social contagion is associated with adoption of these imaging modalities.

Methods

We used Surveillance, Epidemiology, and End Results-Medicare to construct peer groups of physicians who shared patients during a baseline period when these imaging modalities were starting to disseminate into practice (2004-2006) and determined the potential impact of these peer groups during a follow-up period (2007-2009). For non-early-adopting surgeons (whose patients did not receive MRI/PET during baseline), we used hierarchical logistic regression models to examine the effect of their peer group's baseline use on their use of MRI/PET during the follow-up period, adjusting for patient characteristics and hospital MRI/PET use.

Results

For MRI, there were 6424 women diagnosed in the follow-up period assigned to 986 non-early-adopting surgeons. During baseline, 9.3% of women received an MRI, varying across peer groups from 0% to 81%. Women assigned to surgeons whose peers had the highest rate of baseline MRI use were more likely to receive MRI compared with women whose surgeons' peers did not use MRI (24.9% vs 10.1%, adjusted odds ratio [OR] = 2.47, 95% confidence interval [CI] = 1.39 to 4.39). Physician peers were associated with uptake of PET imaging (OR for highest vs lowest baseline peer group PET use = 2.04, 95% CI = 1.24 to 3.36).

Conclusions

The phenomenon of social contagion may offer opportunities to better understand how new approaches to cancer care disseminate into clinical practice.

Overdiagnosis in breast imaging

The main harm of overdiagnosis is overtreatment. However a form of overdiagnosis also occurs when foci of cancer are found by imaging in addition to the symptomatic lesion when this leads to additional treatment which does not benefit the patient. Even if overtreatment is avoided, knowledge of the diagnosis can still cause psychological harm. Overdiagnosis is an inevitable effect of mammographic screening as the benefit comes from diagnosing breast cancer prior to clinical detectability. Estimates of the rate of overdiagnosis at screening are around 10%. DCIS represents 20% of cancers detected by screening and is the main focus in the overdiagnosis debate. Detection and treatment of low grade DCIS and invasive tubular cancer would appear to represent overdiagnosis in most cases. Supplementary screening with tomosynthesis or US are both likely to increase overdiagnosis as both modalities detect predominantly low grade invasive cancers. MRI causes overdiagnosis because it is so sensitive that it detects real tumour foci which after radiotherapy and systemic therapy do not, in many cases go on and cause local recurrence if the women had had no MRI and undergone breast conservation and adjuvant therapy with these small foci left in situ.

Preoperative breast magnetic resonance imaging and contralateral breast cancer occurrence among older women with ductal carcinoma in situ

Although preoperative magnetic resonance imaging (MRI) can detect mammographically occult contralateral breast cancers (CBCs) among women with ductal carcinoma in situ (DCIS), the impact of MRI on the incidence of subsequent CBC events is unclear. We examined whether MRI use decreases CBC occurrences and detection of invasive disease among women who develop a CBC. Utilizing the Surveillance, Epidemiology, and End Results-Medicare dataset, we assessed overall, synchronous (<6 months after primary cancer diagnosis), and subsequent (≥6 months after diagnosis, i.e., metachronous) CBC occurrence in women aged 67-94 years diagnosed with DCIS during 2004-2009, with follow-up through 2011. We applied a matched propensity score approach to compare the stage-specific incidence rate of CBC according to MRI use. Our sample consisted of 9166 beneficiaries, 1258 (13.7 %) of whom received preoperative MRI. After propensity score matching, preoperative MRI use was significantly associated with a higher synchronous CBC detection rate (108.6 vs. 29.7 per 1000 person-years; hazard ratio [HR] = 3.65; p < .001) with no significant differences in subsequent CBC rate (6.7 vs. 6.8 per 1000 person-years; HR = 0.90; p = .71). The 6-year cumulative incidence of any CBC (in situ plus invasive) remained significantly higher among women undergoing MRI, compared with those not undergoing MRI (9 vs. 4 %, p < .001). Women undergoing MRI also had a higher incidence of invasive CBC (4 vs. 3 %, p = .04). MRI use resulted in an increased detection of synchronous CBC but did not prevent subsequent CBC occurrence, suggesting that many of the undetected CBC lesions may not become clinically evident.

Update in treatment of early breast cancer in post-menopausal women

In the last few years there have been significant advances in knowledge related to the treatment of post-menopausal women with early stage breast cancer. These include new information about the survival benefits with hormonal therapies and bone targeted treatments as well as identification of patient populations who may be able to avoid toxic treatments. In this paper we discuss these advances and provide suggested management algorithms.