Breast MRI in nonpalpable breast lesions: a randomized trial with diagnostic and therapeutic outcome - MONET - study

A Systematic Review and Meta-analysis of the Role of Preoperative MRI in In-breast Tumor Recurrence After Breast-Conserving Surgery

BACKGROUND

It is unknown whether the identification of additional tumors in the breast using preoperative magnetic resonance imaging (pMRI) results in a lower risk of in-breast tumor recurrence (IBTR) after breast-conserving surgery (BCS).

METHODS

A systematic review and meta-analysis of relevant studies were performed. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

From 768 citations, 20 studies met the inclusion criteria for the systematic review. The 20 studies consisted of 14 retrospective reviews, 3 matched cohorts, and 3 randomized controlled trials. Whereas 2 studies reported a statistically significant lower rate of IBTR with pMRI, 18 studies showed no difference, and no studies reported a higher rate. Of the 18 studies showing no significant difference, 12 demonstrated a trend toward a lower IBTR rate in the pMRI group. The criteria for meta-analysis were met by 16 studies. A meta-analysis of 11 studies that reported hazard ratios (HR) for IBTR showed a trend toward a lower rate of IBTR for patients who received preoperative MRI (hazard ratio (HR), 0.89; 95% confidence interval (CI), 0.74-1.05). A meta-analysis of five studies that reported event rates and had similar follow-up duration for both groups demonstrated a lower relative risk (RR) of IBTR (RR, 0.45; 95% CI 0.25-0.81).

CONCLUSIONS

Although some evidence supports the hypothesis that identification of additional tumors in the breast using pMRI results in lower rates of IBTR after BCS, the main meta-analysis in this study did not confirm this hypothesis.

Cost-effectiveness of preoperative magnetic resonance imaging to optimize surgery in ductal carcinoma in situ of the breast

PURPOSE

Complete surgical excision is the main factor for successful breast-conserving surgery in patients with ductal carcinoma in situ (DCIS) of the breast. Preoperative magnetic resonance imaging (MRI) may allow surgery optimization in this indication. From an economic standpoint, systematic preoperative MRI is associated with an extra cost, which may be offset by a decrease in the number of re-interventions. We performed an economic evaluation alongside IRCIS randomised controlled trial (NCT01112254) to determine whether systematic preoperative MRI in DCIS is a cost-effective strategy.

METHODS

360 patients were included in IRCIS trial. Costs were assessed from the French national health insurance perspective. Resource use was prospectively collected during a 6-month period after randomisation. We estimated the mean cost per averted re-intervention.

RESULTS

Despite extra costs due to MRI and additional biopsies, difference in total costs between arms was not statistically significant (mean cost of €9980 in MRI arm and €9682 in no MRI arm, cost difference: €298 [CI95% : -470; 1063]). There was a non-significant decrease in the rate of re-hospitalisations for positive or close margins (20% in MRI arm versus 27% in No MRI arm, difference -7% [CI95% : -17; 3]). At a willingness to pay of €500 to avert a re-intervention, the probability that MRI strategy is cost-effective was 93%.

CONCLUSION

Systematic preoperative MRI in patients with DCIS of the breast may be a cost-effective strategy. However, the modest clinical benefit associated with such a strategy limits the interest for this procedure in routine practice given the current MRI techniques.

Methylation profiling in promoter sequences of ATM and CDKN2A (p14ARF/p16INK4a ) genes in blood and cfDNA from women with impalpable breast lesions

The objective of the present study was to evaluate the epigenetic changes occurring in early stages of breast cancer. The present study investigated the methylation profile of the ATM, p14^ARF and p16^INK4a promoters in total blood and plasma cell-free DNA (cfDNA) from women with impalpable breast lesions compared with in total blood of a control cohort of women without breast lesions. The samples were evaluated using the methylation-specific PCR method. The Fisher's exact test was used to evaluate statistical significance between the methylation and clinical variables. A total of 111 women were evaluated, including 56 women with impalpable breast cancer (39/56 also had paired plasma cfDNA) and 55 women in the control cohort (55 blood DNA). For blood DNA from women with malignant impalpable breast lesions, p16^INK4a exhibited the greatest percentage of methylation (48%), followed by ATM (37.5%) and p14^ARF (27%) promoters, regardless of age variation. For plasma cfDNA, the methylation rates for ATM, p14^ARF and p16^INK4a were 26, 26 and 10%, respectively. The methylation rates for the blood DNA of controls were the lowest for ATM (9%), p14^ARF (7%) and p16^INK4a (7%). The women with impalpable breast lesions (benign and malignant lesions) exhibited the highest methylation rate, regardless of age, compared with the paired plasma cfDNA and controls. This epigenetic change was statistically significant for the promoters of ATM (P=0.009) and p16^INK4a (P=0.001) (impalpable breast lesions vs. control). The present study demonstrated that epigenetic changes occurring in the ATM and CDKN2A genes detectable in liquid biopsy were associated with the development of impalpable breast lesions.

Magnetic resonance imaging in breast cancer: A literature review and future perspectives

Early detection and diagnosis of breast cancer are essential for successful treatment. Currently mammography and ultrasound are the basic imaging techniques for the detection and localization of breast tumors. The low sensitivity and specificity of these imaging tools resulted in a demand for new imaging modalities and breast magnetic resonance imaging (MRI) has become increasingly important in the detection and delineation of breast cancer in daily practice. However, the clinical benefits of the use of pre-operative MRI in women with newly diagnosed breast cancer is still a matter of debate. The main additional diagnostic value of MRI relies on specific situations such as detecting multifocal, multicentric or contralateral disease unrecognized on conventional assessment (particularly in patients diagnosed with invasive lobular carcinoma), assessing the response to neoadjuvant chemotherapy, detection of cancer in dense breast tissue, recognition of an occult primary breast cancer in patients presenting with cancer metastasis in axillary lymph nodes, among others. Nevertheless, the development of new MRI technologies such as diffusion-weighted imaging, proton spectroscopy and higher field strength 7.0 T imaging offer a new perspective in providing additional information in breast abnormalities. We conducted an expert literature review on the value of breast MRI in diagnosing and staging breast cancer, as well as the future potentials of new MRI technologies.

Multicentric and contralateral invasive tumors identified with pre-op MRI in patients newly diagnosed with ductal carcinoma in situ of the breast

Preoperative breast MRI in newly diagnosed cancer patients has several potential benefits. Improved survival for patients with invasive disease as the index lesion is unlikely to be one of these benefits, given what is known from variations in locoregional management in the historic conservation trials. However, this may not be the case for patients with ductal carcinoma in situ (DCIS), as the discovery of unsuspected invasive cancer located elsewhere from the biopsy-proven DCIS could result in decreased survival if left undetected and untreated. In support of this hypothesis, a previous observational study of a large cohort of DCIS patients revealed the development of invasive cancer to be the most common event after unilateral DCIS treatment, occurring in 3.9%, mostly in the opposite breast. These cancers appeared on mammography or clinical exam within a short time frame (median 2.9 years) and were associated with a diminution in survival. Given these second events occurring so soon after DCIS treatment, it must be considered that invasive cancers were present elsewhere, but mammographically occult, at the time of DCIS diagnosis. To examine this possibility, 288 consecutive patients with newly diagnosed DCIS underwent preoperative MRI, with the discovery of separate foci of invasive cancer, either multicentric or contralateral, occurring in 3.5% of patients, a similar incidence to the short-term observational study. These "elsewhere" invasive cancers are presented here with details of pathology such that both Stage I and Stage II disease can be seen as clinically significant, with the usual stage-based survival implications.

Preoperative breast MRI in the surgical treatment of ductal carcinoma in situ

Accurate determination of the size or extent of ductal carcinoma in situ (DCIS) by imaging is uncertain, and incomplete resection of tumor results in involved margins in up to 81% of cases. This study examined the accuracy of magnetic resonance imaging (MRI) for assessment of DCIS size, and evaluated the effect of preoperative breast MRI on achievement of tumor-free surgical margins after breast-conserving surgery (BCS). One-hundred and fifty-eight female patients with DCIS were identified from a prospective database: 60 patients (62 cases) had preoperative breast MRI, and 98 patients did not have MRI. The accuracy of tumor size assessed by MRI was determined by comparison with histopathologic size. All patients underwent BCS initially. The rate of involved margins after resection was compared in MRI and no-MRI groups. The overall correlation between MRI size and histopathologic size was high (p < 0.0001). MRI assessment of size was significantly more accurate when DCIS was high grade (p < 0.0001) or intermediate grade (p = 0.005) versus low grade (p = 0.187). The rate of tumor-involved margins was not significantly different in MRI and no-MRI groups (30.7% and 24.7%, respectively; p = 0.414). The rate of mastectomy was significantly higher in the MRI group than the no-MRI group (17.7% versus 4.1%; p = 0.004). These findings indicate that MRI can detect DCIS, especially when lesions are high or intermediate grade, but that MRI does not accurately predict the size of DCIS. In this study, MRI did not improve the surgeon's ability to achieve clear margins following BCS.

Role of science in the treatment of breast cancer when tumor multicentricity is present

During the past 100 years, there have been two major controversies with regard to the treatment of primary breast cancer. The first controversy, which occurred approximately 35 years ago, questioned the performance of radical mastectomy, as originally proposed by Halsted in the 1890s. That controversy was resolved by the use of laboratory and clinical research, hypothesis formulation, and evaluation of the efficacy of the latter through the conduct of randomized clinical trials. A second major controversy arose when magnetic resonance imaging began to detect the presence of tumor multicentricity in many breast cancer patients, resulting in a resurgence in mastectomy in women who could have been treated with breast-preserving surgery. Because the use of science resolved the first controversy, I investigated whether there was scientific evidence to justify the current reversion to mastectomy. Extensive examination of the vast amount of recent medical literature related to that subject, that is, individual articles, review articles, and reports from the use of clinical trials, demonstrated that many physicians are not familiar with the scientific method, and thus, were unable to present, in those articles, credible evidence to support mastectomy in the presence of tumor cell multicentricity. Aside from the randomized clinical trial conducted by the National Surgical Adjuvant Breast and Bowel Project begun in 1976, which demonstrated no statistically significant difference in disease-free survival, distant disease-free survival, and overall survival between mastectomy and lumpectomy with or without radiation therapy, there has been no information in any of the few recently conducted studies involving multicentricity to justify the current resurgence in mastectomy.

A novel approach to identify non-palpable breast lesions combining fluorescent liposomes and magnetic resonance-guided high intensity focused ultrasound-triggered release

The combination of fluorescein-containing liposomes (FCL) and magnetic resonance-guided high intensity focused ultrasound (MR-HIFU)-triggered release is a promising approach for lesion demarcation and more efficient removal of non-palpable breast lesions. Exposure of FCL to ablation temperatures (60 °C) using MR-HIFU would result in palpable, stained tumors, which are more easy to identify during surgical resection. In this study, proof-of-concept concerning fluorescent FCL for MR-HIFU-triggered release and tumor demarcation of non-palpable breast lesions is presented. Ex vivo experiments in human blood and porcine muscle tissue showed increased label release from the liposomes, clear fluorescence enhancement and diffusion of the released compound after heating to 60 °C. Next, fluorescein release of FCL was observed after MR-HIFU-mediated mild hyperthermia (42 °C) and ablation temperature (60 °C) for a short period (30s), which is in line with the clinically relevant MR-HIFU treatment parameters. These results indicate the potential of the FCL as a tool to improve tumor demarcation in patients by MR-HIFU-triggered release. Therefore, this method may offer a new tool for efficient surgical resection of non-palpable breast tumor lesions by enabling proper discrimination between tumor tissue and adjacent healthy tissue.

Preoperative MRI and surgical management in patients with nonpalpable breast cancer: the MONET - randomised controlled trial

BACKGROUND

We evaluated whether performing contrast-enhanced breast MRI in addition to mammography and/or ultrasound in patients with nonpalpable suspicious breast lesions improves breast cancer management.

METHODS

The MONET - study (MR mammography of nonpalpable breast tumours) is a randomised controlled trial in patients with a nonpalpable BIRADS 3-5 lesion. Patients were randomly assigned to receive routine medical care, including mammography, ultrasound and lesion sampling by large core needle biopsy or additional MRI preceding biopsy. Patients with cancer were referred for surgery. Primary end-point was the rate of additional surgical procedures (re-excisions and conversion to mastectomy) in patients with a nonpalpable breast cancer.

FINDINGS

Four hundred and eighteen patients were randomised, 207 patients were allocated to MRI, and 211 patients to the control group. In the MRI group 74 patients had 83 malignant lesions, compared to 75 patients with 80 malignant lesions in the control group. The primary breast conserving surgery (BCS) rate was similar in both groups; 68% in the MRI group versus 66% in the control group. The number of re-excisions performed because of positive resection margins after primary BCS was increased in the MRI group; 18/53 (34%) patients in the MRI group versus 6/50 (12%) in the control group (p=0.008). The number of conversions to mastectomy did not differ significantly between groups. Overall, the rate of an additional surgical intervention (BCS and mastectomy combined) after initial breast conserving surgery was 24/53 (45%) in the MRI group versus 14/50 (28%) in the control group (p=0.069).

INTERPRETATION

Addition of MRI to routine clinical care in patients with nonpalpable breast cancer was paradoxically associated with an increased re-excision rate. Breast MRI should not be used routinely for preoperative work-up of patients with nonpalpable breast cancer.

Magnetic resonance imaging of the breast: recommendations from the EUSOMA working group

The use of breast magnetic resonance imaging (MRI) is rapidly increasing. EUSOMA organised a workshop in Milan on 20-21st October 2008 to evaluate the evidence currently available on clinical value and indications for breast MRI. Twenty-three experts from the disciplines involved in breast disease management - including epidemiologists, geneticists, oncologists, radiologists, radiation oncologists, and surgeons - discussed the evidence for the use of this technology in plenary and focused sessions. This paper presents the consensus reached by this working group. General recommendations, technical requirements, methodology, and interpretation were firstly considered. For the following ten indications, an overview of the evidence, a list of recommendations, and a number of research issues were defined: staging before treatment planning; screening of high-risk women; evaluation of response to neoadjuvant chemotherapy; patients with breast augmentation or reconstruction; occult primary breast cancer; breast cancer recurrence; nipple discharge; characterisation of equivocal findings at conventional imaging; inflammatory breast cancer; and male breast. The working group strongly suggests that all breast cancer specialists cooperate for an optimal clinical use of this emerging technology and for future research, focusing on patient outcome as primary end-point.

Diagnostic breast magnetic resonance imaging and contralateral prophylactic mastectomy

BACKGROUND

Preoperative use of breast magnetic resonance imaging (MRI) in women with breast cancer may increase rates of mastectomy. This study investigated relationships between breast MRI and therapeutic and contralateral prophylactic mastectomy (CPM) in women with breast cancer.

METHODS

A total of 3606 women diagnosed with stage 0-III breast cancer from 1998 through 2000 (n = 1743; early period) or from 2003 through 2005 (n = 1863; late period) were retrospectively identified. Patient demographic and clinical characteristics were obtained from our institution's tumor registry. MRI use in the diagnostic evaluation was obtained from a prospective radiology database. Rates of therapeutic mastectomy, CPM, and associations with breast MRI were compared between the two time periods by multiple logistic regressions controlling for disease stage, age, family history, and calendar year of diagnosis.

RESULTS

A total of 14.2% of women underwent MRI, 29.0% had mastectomy, and 5.3% had CPM. Use of breast MRI increased substantially between the two time periods (4.1% to 23.7%, P < 0.001). Mastectomy rates increased from 28% to 30% (P > 0.05). The rate of CPM increased by >50% from the early to late period (4.1% to 6.4%, P < 0.002). Women who underwent MRI were nearly twice as likely to have CPM (9.2 vs. 4.7%, P < 0.001). Multivariate models found MRI was associated with increased rates of CPM for women with stage I or II disease (odds ratio 2.04, P = 0.001).

CONCLUSIONS

MRI changes the surgical treatment of breast cancer among subsets of women diagnosed with breast cancer, suggesting there are hidden monetary and nonmonetary costs associated with its use.