Yield of surveillance magnetic resonance imaging after bilateral mastectomy and reconstruction: a retrospective cohort study

Society of Surgical Oncology Breast Disease Site Working Group Statement on Contralateral Mastectomy: Indications, Outcomes, and Risks

Rates of contralateral mastectomy (CM) among patients with unilateral breast cancer have been increasing in the United States. In this Society of Surgical Oncology position statement, we review the literature addressing the indications, risks, and benefits of CM since the society's 2017 statement. We held a virtual meeting to outline key topics and then conducted a literature search using PubMed to identify relevant articles. We reviewed the articles and made recommendations based on group consensus. Patients consider CM for many reasons, including concerns regarding the risk of contralateral breast cancer (CBC), desire for improved cosmesis and symmetry, and preferences to avoid ongoing screening, whereas surgeons primarily consider CBC risk when making a recommendation for CM. For patients with a high risk of CBC, CM reduces the risk of new breast cancer, however it is not known to convey an overall survival benefit. Studies evaluating patient satisfaction with CM and reconstruction have yielded mixed results. Imaging with mammography within 12 months before CM is recommended, but routine preoperative breast magnetic resonance imaging is not; there is also no evidence to support routine postmastectomy imaging surveillance. Because the likelihood of identifying an occult malignancy during CM is low, routine sentinel lymph node surgery is not recommended. Data on the rates of postoperative complications are conflicting, and such complications may not be directly related to CM. Adjuvant therapy delays due to complications have not been reported. Surgeons can reduce CM rates by encouraging shared decision making and informed discussions incorporating patient preferences.

Yield of Surveillance Imaging After Mastectomy With or Without Reconstruction for Patients With Prior Breast Cancer: A Systematic Review and Meta-analysis

IMPORTANCE

A discrepancy on current guidelines and clinical practice exists regarding routine imaging surveillance after mastectomy, mainly regarding the lack of adequate evidence for imaging in this setting.

OBJECTIVE

To investigate the usefulness of imaging surveillance in terms of cancer detection and interval cancer rates after mastectomy with or without reconstruction for patients with prior breast cancer.

DATA SOURCES

A comprehensive literature search was conducted in 3 electronic databases-PubMed, ISI Web of Science, and Scopus-without year restriction. References from relevant reviews and eligible studies were also manually searched.

STUDY SELECTION

Eligible studies were defined as those conducting surveillance imaging (mammography, ultrasonography, or magnetic resonance imaging [MRI]) of patients with prior breast cancer after mastectomy with or without reconstruction that presented adequate data to calculate cancer detection rates for each surveillance method.

DATA EXTRACTION AND SYNTHESIS

Independent data extraction by 2 investigators with consensus on discrepant results was performed. A quality assessment of studies was performed using the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2) template. The generalized linear mixed model framework with both fixed-effects and random-effects models was used to meta-analyze the proportion of cases across studies including 3 variables: surveillance method, reconstruction after mastectomy, and surveillance measure.

MAIN OUTCOMES AND MEASURES

Three outcome measures were calculated for each eligible study and each surveillance imaging method within studies: overall cancer detection (defined as ipsilateral cancer, both palpable and nonpalpable) rate per 1000 examinations, clinically occult (nonpalpable) cancer detection rate per 1000 examinations, and interval cancer rate per 1000 examinations.

RESULTS

In total, 16 studies were eligible for the meta-analysis. The pooled overall cancer detection rates per 1000 examinations were 1.86 (95% CI, 1.05-3.30) for mammography, 2.66 (95% CI, 1.48-4.76) for ultrasonography, and 5.17 (95% CI, 1.49-17.75) for MRI. For mastectomy without reconstruction, the rate of clinically occult (nonpalpable) cancer per 1000 examinations (2.96; 95% CI, 1.38-6.32) and the interval cancer rate per 1000 examinations (3.73; 95% CI, 0.84-3.98) were lower than the overall cancer detection rate (including both palpable and nonpalpable lesions) per 1000 examinations (6.41; 95% CI, 3.09-13.25) across all imaging modalities. The interval cancer rate per 1000 examinations for mastectomy with reconstruction (3.73; 95% CI, 0.41-2.73) was comparable to the pooled cancer detection rate per 1000 examinations (4.73; 95% CI, 2.32-9.63) across all imaging modalities. In all clinical scenarios and imaging modalities, lower rates of clinically occult cancer compared with cancer detection rates were observed.

CONCLUSIONS AND RELEVANCE

Lower detection rates of clinically occult-compared with overall-cancer across all 3 imaging modalities challenge the use of imaging surveillance after mastectomy, with or without reconstruction. Findings suggest that imaging surveillance in this context is unnecessary in clinical practice, at least until further studies demonstrate otherwise. Future studies should consider using the clinically occult cancer detection rate as a more clinically relevant measure in this setting.

ACR Appropriateness Criteria® Imaging After Mastectomy and Breast Reconstruction

Mastectomy may be performed to treat breast cancer or as a prophylactic approach in women with a high risk of developing breast cancer. In addition, mastectomies may be performed with or without reconstruction. Reconstruction approaches differ and may be autologous, involving a transfer of tissue (skin, subcutaneous fat, and muscle) from other parts of the body to the chest wall. Reconstruction may also involve implants. Implant reconstruction may occur as a single procedure or as multistep procedures with initial use of an adjustable tissue expander allowing the mastectomy tissues to be stretched without compromising blood supply. Ultimately, a full-volume implant will be placed. Reconstructions with a combination of autologous and implant reconstruction may also be performed. Other techniques such as autologous fat grafting may be used to refine both implant and flap-based reconstruction. This review of imaging in the setting of mastectomy with or without reconstruction summarizes the literature and makes recommendations based on available evidence. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Assessing the Utility of Post-Mastectomy Imaging after Breast Reconstruction

BACKGROUND

Few guidelines exist regarding surveillance and diagnostic imaging after breast reconstruction. This study investigated the influence of breast reconstruction on the frequency of post-mastectomy imaging, the relative utility of imaging, and its effect on overall and locoregional recurrence-free survival.

STUDY DESIGN

A retrospective review identified breast cancer patients (n = 1,216) who underwent mastectomy with or without reconstruction. Logistic regression identified surgical and oncologic predictors of post-reconstruction imaging. Kaplan-Meier method determined the impact of post-reconstruction imaging on overall and locoregional recurrence-free survival.

RESULTS

Overall, 662 (54.4%) patients underwent mastectomy only and 554 (45.6%) underwent breast reconstruction. Patients undergoing reconstruction were more likely to receive imaging compared with patients undergoing mastectomy only (n = 205, 37.0% vs n = 168, 25.4%; p < 0.0001); however, this difference was not statistically significant after adjusting for age and follow-up time (p = 0.16). Most radiographic studies were Breast Imaging Reporting and Data System (BI-RADS) 1 (n = 58, 30%) or 2 (n = 95, 49%) and were ordered by nonsurgical providers (n = 128, 63%). Post-reconstruction imaging did not influence overall or locoregional recurrence-free survival. The 5-year survival probabilities for breast reconstruction patients who underwent imaging for a palpable mass, surveillance, or who did not undergo imaging were 100%, 95% (95% CI 89% to 100%), and 96% (95% CI 94% to 99%), respectively. Post-reconstruction imaging was not a significant predictor of overall survival (hazard ratio [HR] 0.95; 95% CI 0.61 to 1.46; p = 0.30).

CONCLUSIONS

The limited utility of routine post-reconstruction imaging should be reinforced when evaluating breast reconstruction patients. Multidisciplinary collaboration should be emphasized when attempting to distinguish benign postoperative findings from a malignant process to reduce unnecessary imaging and biopsy after breast reconstruction.