Breast-Conserving Surgery Margin Guidance Using Micro-Computed Tomography: Challenges When Imaging Radiodense Resection Specimens

BACKGROUND

Breast-conserving surgery (BCS) is an integral component of early-stage breast cancer treatment, but costly reexcision procedures are common due to the high prevalence of cancer-positive margins on primary resections. A need exists to develop and evaluate improved methods of margin assessment to detect positive margins intraoperatively.

METHODS

A prospective trial was conducted through which micro-computed tomography (micro-CT) with radiological interpretation by three independent readers was evaluated for BCS margin assessment. Results were compared to standard-of-care intraoperative margin assessment (i.e., specimen palpation and radiography [abbreviated SIA]) for detecting cancer-positive margins.

RESULTS

Six hundred margins from 100 patients were analyzed. Twenty-one margins in 14 patients were pathologically positive. On analysis at the specimen-level, SIA yielded a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 42.9%, 76.7%, 23.1%, and 89.2%, respectively. SIA correctly identified six of 14 margin-positive cases with a 23.5% false positive rate (FPR). Micro-CT readers achieved sensitivity, specificity, PPV, and NPV ranges of 35.7-50.0%, 55.8-68.6%, 15.6-15.8%, and 86.8-87.3%, respectively. Micro-CT readers correctly identified five to seven of 14 margin-positive cases with an FPR range of 31.4-44.2%. If micro-CT scanning had been combined with SIA, up to three additional margin-positive specimens would have been identified.

DISCUSSION

Micro-CT identified a similar proportion of margin-positive cases as standard specimen palpation and radiography, but due to difficulty distinguishing between radiodense fibroglandular tissue and cancer, resulted in a higher proportion of false positive margin assessments.

Factors influencing suboptimal pathologic margins and re-excision following breast conserving surgery for ductal carcinoma in-situ

INTRODUCTION

Re-excisions following breast conserving surgery (BCS) are common, occurring more frequently in ductal carcinoma in-situ (DCIS) than its' malignant counterpart. Although one quarter of patients with breast cancer will have DCIS, there is limited information available regarding factors predisposing to inadequate pathologic margins, and the need for re-excision.

METHODS

Retrospective review of patients treated for DCIS between the years 2010-2016 was conducted. Patients with DCIS undergoing BCS were identified and evaluated for demographic and pathologic factors associated with suboptimal pathologic margins and re-excision. Multivariate analysis with Wald Chi-Square testing was performed.

RESULTS

241 patients underwent BCS with suboptimal margins (SOM) in 51.7% (123/238), with 27.8% undergoing re-excision (67/241). Tumor size was the most influential variable, positively associated with SOM (OR = 10.25, CI: 5.50-19.13) and re-excision (OR = 6.36, CI: 3.92-10.31). Patient age was inversely associated with SOM (OR = 0.58, CI: 0.39-0.85) and subsequent re-excisions (OR = 0.56, CI: 0.36-0.86). Low tumour grade was associated with re-excision (OR = 1.31, CI: 0.63-2.71), while ER negative disease was associated with SOM (OR = 2.24, CI: 1.21-4.14).

DISCUSSION

Inadequate pathologic margins following BCS, and subsequent re-excision rates are common in patients with DCIS, and consistent with the literature. Tumour size is the dominant factor driving this occurrence, with patient age and tumour grade also impacting outcomes.

Intraoperative fluorescence imaging with aminolevulinic acid detects grossly occult breast cancer: a phase II randomized controlled trial

BACKGROUND

Re-excision due to positive margins following breast-conserving surgery (BCS) negatively affects patient outcomes and healthcare costs. The inability to visualize margin involvement is a significant challenge in BCS. 5-Aminolevulinic acid hydrochloride (5-ALA HCl), a non-fluorescent oral prodrug, causes intracellular accumulation of fluorescent porphyrins in cancer cells. This single-center Phase II randomized controlled trial evaluated the safety, feasibility, and diagnostic accuracy of a prototype handheld fluorescence imaging device plus 5-ALA for intraoperative visualization of invasive breast carcinomas during BCS.

METHODS

Fifty-four patients were enrolled and randomized to receive no 5-ALA or oral 5-ALA HCl (15 or 30 mg/kg). Forty-five patients (n = 15/group) were included in the analysis. Fluorescence imaging of the excised surgical specimen was performed, and biopsies were collected from within and outside the clinically demarcated tumor border of the gross specimen for blinded histopathology.

RESULTS

In the absence of 5-ALA, tissue autofluorescence imaging lacked tumor-specific fluorescent contrast. Both 5-ALA doses caused bright red tumor fluorescence, with improved visualization of tumor contrasted against normal tissue autofluorescence. In the 15 mg/kg 5-ALA group, the positive predictive value (PPV) for detecting breast cancer inside and outside the grossly demarcated tumor border was 100.0% and 55.6%, respectively. In the 30 mg/kg 5-ALA group, the PPV was 100.0% and 50.0% inside and outside the demarcated tumor border, respectively. No adverse events were observed, and clinical feasibility of this imaging device-5-ALA combination approach was confirmed.

CONCLUSIONS

This is the first known clinical report of visualization of 5-ALA-induced fluorescence in invasive breast carcinoma using a real-time handheld intraoperative fluorescence imaging device.

TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT01837225 . Registered 23 April 2013.

Evaluating the Quality of Cost-Effectiveness Literature in Breast Surgery: What Do We Do Well and How Can We Do Better? A Systematic Review

BACKGROUND

Surgical options for breast cancer are numerous and span multiple surgical disciplines. Decision analyses aid surgeons in making the most cost-effective choice, thus reducing health care expenditure while maximizing patient outcome. In this study, we aimed to evaluate existing breast surgery cost-effectiveness literature against the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) validated scoring system.

METHODS

A PRISMA search was performed for cost-effectiveness within breast surgery. Articles were scored with CHEERS criteria on a 0-24 scale and qualitative data were collected. Subgroup analysis was performed comparing pre-CHEERS (published in 2013 or earlier) and post-CHEERS (published in 2014 or later) cohorts. Chi-squared analysis was performed to compare where studies lost points between cohorts.

RESULTS

Of 2279 articles screened, 46 articles were included. The average CHEERS score was 18.18. Points were most often lost for characterizing heterogeneity, followed by discount rate, incremental costs and outcomes, and abstract. Quality-adjusted life year was the most commonly used health outcome, with visual model or analog scales as the most commonly used measure of effectiveness obtained primarily from surgeons or physicians. Most articles characterized uncertainty by deterministic sensitivity analysis, followed by both deterministic and probabilistic, then probabilistic. Average CHEERS scores were similar between pre- and post-CHEERS cohorts (17.67 vs. 18.40, P > .05) There were several significant differences in where articles lost points between pre- and post-CHEERS cohorts.

DISCUSSION

In order to standardize the reporting of results, cost-effectiveness studies in breast surgery should adhere to the current CHEERS criteria and aim to better characterize heterogeneity in their analyses.

Changes in Reoperation After Publication of Consensus Guidelines on Margins for Breast-Conserving Surgery: A Systematic Review and Meta-analysis

Importance

The 2014 publication of the Society of Surgical Oncology-American Society for Radiation Oncology (SSO-ASTRO) Consensus Guideline on Margins for Breast-Conserving Surgery recommended a negative margin definition of no ink on tumor. Adoption of this guideline would represent a major change in surgical practice that could lower the rates of reoperation.

Objective

To assess changes in reoperation rates after publication of the SSO-ASTRO guideline.

Data Sources

A systematic search of Embase, PREMEDLINE, Evidence-Based Medicine Reviews, Scopus, and Web of Science for biomedical literature published from January 2014 to July 2019 was performed. This search was supplemented by web searches and manual searching of conference abstracts.

Study Selection

Included studies compared the reoperation rates in preguideline vs postguideline cohorts (actual change), retrospectively applied the SSO-ASTRO guideline to a preguideline cohort (projected change), or described the economic outcomes of the guideline.

Data Extraction and Synthesis

Study characteristics and reoperation rates were extracted independently by 2 reviewers. Odds ratios (ORs) were pooled by random effects meta-analysis. Analyses were stratified by study setting (institutional or population) and preguideline accepted margins. The economic outcomes of the guideline were summarized narratively. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline was followed.

Main Outcomes and Measures

Odds ratios for postguideline vs preguideline reoperation rates.

Results

From 1114 citations, 30 studies (with 599 016 participants) reported changes in reoperation rates. Studies included a median (range) of 487 (100-521 578) participants, and 20 studies were undertaken in the US, 6 in the UK, 3 in Canada, and 1 in Australia. Among 21 studies of actual changes, pooled ORs showed a statistically significant reduction in reoperation, with an OR lower in institution-based studies than in population-based studies (OR, 0.62 [95% CI, 0.52-0.74] vs 0.76 [95% CI, 0.72-0.80]; P = .04 for subgroup differences). Among 9 studies of projected changes, the pooled OR was lower for preguideline margin thresholds of 2 mm or more compared with 1 mm (OR, 0.47 [95% CI, 0.40-0.56] vs 0.85 [95% CI, 0.79-0.91; P < .001 for subgroup differences). Projected changes were likely to overestimate actual changes. Six studies that estimated the postguideline economic outcome found the guideline to be potentially cost saving, with a median (range) saving of US $3540 ($1800-$25 650) per woman avoiding reoperation.

Conclusions and Relevance

This study found a decrease in reoperation rates after the publication of the SSO-ASTRO guideline; this reduction was greater at an institutional level than a population level, the latter reflecting the differences in guideline adoption between centers. These early outcomes may be conservative estimates of longer-term implications.

Intraoperative near-infrared imaging can identify canine mammary tumors, a spontaneously occurring, large animal model of human breast cancer

Introduction

Current methods of intraoperative margin assessment in breast conserving surgery are impractical, unreliable, or time consuming. We hypothesized that intraoperative near-infrared (NIR) imaging with an FDA-approved NIR optical contrast agent could identify canine mammary tumors, a spontaneous large animal model of human breast cancer, during surgery.

Methods

Dogs with mammary tumors underwent a standard of care lumpectomy or mastectomy with wide surgical margins 20 hours after indocyanine green administration (3 mg/kg IV). During surgery, NIR imaging was performed on tumors and wound margins in situ and tumors and lymph nodes ex vivo. Following resection, the wound bed was examined for residual fluorescence. Fluorescence intensity was determined by signal-to-background ratio (SBR). All tumors, areas of residual fluorescence, and lymph nodes underwent histopathologic analysis.

Results

There were 41 mammary tumors in 16 female dogs. Twenty tumors were malignant and 21 were benign. Twenty-eight tumors were fluorescent (mean SBR 1.5±0.2). Sensitivity of fluorescence for all malignant tumors was 80% (16/20) and 93.3% (14/15) for malignant tumors > 2 cm. Specificity for malignancy was low (< 2cm = 55%; > 2cm = 30%). Tumors > 2 cm were more likely to be fluorescent (OR 6.05, 95% CI 1.50–24.44, P = 0.011) but not more likely to be malignant (OR 3.09, 95% CI 0.86–11.14, P = 0.085) than tumors ≤ 2 cm. Four out of seven inguinal lymph nodes excised in the mastectomy specimen fluoresced. All four drained malignant tumors; however only 2/4 contained metastatic disease.

Conclusion

Systemic ICG accumulates reliably in malignant canine mammary tumors > 2 cm. Although no tumor margins fluoresced, a wider margin of normal tissue is removed in canine mastectomy, making direct comparisons with breast conserving surgery difficult. Targeted NIR imaging agents are likely required to improve detection of smaller tumors and improve the specificity of NIR imaging for residual disease and metastatic lymph node detection.

Impact of Resident and Fellow Participation on Surgical Outcomes in Breast Conserving Surgery for Invasive Breast Cancer

OBJECTIVE

Few studies examine the impact of surgical trainee involvement on tumor-free margins in breast conserving surgery (BCS). Our objective was to investigate the impact of resident and fellow involvement on positive margins rates following BCS for invasive breast cancer (BC).

DESIGN

We identified female patients who had BCS for BC between January 2005 to December 2015.

SETTING

Tertiary care hospital.

PARTICIPANTS

Around 1089 patients were identified from a prospectively maintained database.

RESULTS

Of 1089 patients, mean age was 63 (range 43-99) years. Around 768 patients (70.1%) required preoperative localization, and 328 patients (29.9%) had a palpable cancer. Nonpalpable cancers had a smaller volume of specimen tissue excised (p = 0.0005) compared to palpable cancers, and no significant difference was observed in the positive margin rate between the nonpalpable group compared to the palpable group (24.7% nonpalpable vs. 25.3% palpable, p = 0.88). Nonpalpable cancer positive margin rates were 23.9% (n = 102/427) for cases performed by an attending surgeon, 25.0% (n = 15/60) with a junior resident (PGY 2-3), 28.6% (n = 8/28) with a senior resident (PGY 4-5), and 25.7% (n = 65/253) with a fellow, which were not statistically significant (p = 0.89). Palpable cancer positive margin rates were 27.6% (n = 47/170) for cases performed by an attending, 13.9% (n = 5/36) with an intern (PGY-1), 40.9% (n = 9/22) with a junior resident, 0% (n = 0/8) with a senior resident, and 23.9% (n = 22/92) with a fellow, which were also not significantly different (p = 0.07).

CONCLUSION

Resident and fellow participation in BCS for BC does not appear to impact the rate of positive margins.

Update of the American Society of Breast Surgeons Toolbox to address the lumpectomy reoperation epidemic

In 2015, the American Society of Breast Surgeons (ASBrS) convened a multidisciplinary consensus conference, the Collaborative Attempt to Lower Lumpectomy Reoperation Rates (CALLER). The CALLER conference endorsed a "toolbox" of multiple processes of care for which there was evidence that they were associated with fewer reoperations. We present an update of the toolbox taking into consideration the latest advances in decreasing re excision rates. In this review, we performed a comprehensive review of the literature from 2015-2018 using search terms for each tool. The original ten tools were updated with the latest evidence from the literature and our strength of recommendation. We added an additional section looking at new tools and techniques that may provide more accurate intraoperative assessment of margins. The updates on the CALLER Toolbox for lumpectomy will help guide surgeons to various resources to aid in the removal of breast cancer, while being aware of cosmesis and decreasing re excision rates.

Factors influencing reoperation following breast-conserving surgery

BACKGROUND

Reoperation rates after breast-conserving surgery are highly variable and the best techniques for optimizing margin clearance are being evaluated. The aim was to identify the reoperation rate at our centre and identify influential factors, including a change in guidelines on margin recommendations and the introduction of in-theatre specimen X-ray.

METHODS

A retrospective review of medical records was undertaken to identify 562 patients who underwent breast conservation at The Royal Melbourne Hospital and Royal Women's Hospital between 2013 and 2015. All cases that underwent subsequent re-excision or total mastectomy were captured and factors influencing margin excision recorded.

RESULTS

Reoperation was undertaken in 19.5% of patients (110; 86 re-excisions and 24 total mastectomies). There was a reduction in reoperation rate from 25% to 17% (P = 0.01) with adoption of the margin guidelines in 2014, but no significant reduction with the introduction of in-theatre specimen X-ray in 2015 (21% versus 16%, P = 0.14). On multivariate analysis, factors that significantly influenced reoperation rates were the presence of multifocality on mammogram (odds ratio (OR): 5.3, 95% confidence interval (CI): 1.6-16.7, P < 0.01); lesion size on mammogram (OR: 2.2 per 10 mm, 95% CI: 1.4-3.6, P < 0.01); smaller excision specimen weight (OR: 0.5 per 25 g of resection, 95% CI: 0.3-0.8, P < 0.01); and pure ductal carcinoma in situ on final pathology (OR: 5.9, 95% CI: 1.9-16.7, P < 0.01).

CONCLUSION

Optimizing reoperation rates following breast-conserving surgery remains a surgical challenge, particularly in patients with in situ or multifocal disease. Adoption of international margin guidelines reduced reoperation rates at our centre; however, introduction of intraoperative specimen X-ray had no influence.

Predictors of Residual Disease After Breast Conservation Surgery

INTRODUCTION

Breast-conserving therapy is the standard of care for early-stage breast cancer. In the era of multimodality therapy, the debate on the value of revision surgery for compromised margins continues, and high re-excision rates persist despite updated guidelines. Our study sought to identify the local re-excision rate for compromised margins after lumpectomy, and identify predictors of residual disease at re-excision.

METHODS

This population-based retrospective cohort study included women with breast cancer who underwent a lumpectomy between 2009 and 2012 in Manitoba, with close (≤ 2 mm) or positive margins that led to re-excision. Patient demographics and tumor characteristics were identified through provincial cancer registries and chart reviews. For patients with invasive cancer, the six anatomical margins were reported for margin status, width, and pathology type at the margin.

RESULTS

Of the 2494 patients identified, 556 women underwent re-excision, yielding a re-excision rate of 22.29%. Of our 311 patients with invasive cancer who underwent re-excision, 62.7% had residual disease identified on revision. On univariable analysis, the size and grade of the invasive component, nodal stage, and the number of positive margins were associated with residual disease on re-excision (p < 0.05). With the exception of nodal stage, the same variables remained statistically significant on multivariable analysis.

CONCLUSIONS

Our results suggest that even in the absence of 'no ink on tumor', the cancer size and grade in lumpectomy specimens are high-risk factors for residual disease, and this subgroup of patients may benefit from re-excision. Long-term follow-up of this cohort is required to determine their risk of recurrence after adjuvant treatment.

Evaluating the Effect of Margin Consensus Guideline Publication on Operative Patterns and Financial Impact of Breast Cancer Operation

BACKGROUND

This study sought to evaluate re-excision rates, patient satisfaction with their breasts, and healthcare costs before and after publication of 2014 Society of Surgical Oncology/American Society of Radiation Oncology consensus guideline on margins for breast conserving operation with whole-breast irradiation for stage I and II breast cancer at an academic institution.

STUDY DESIGN

Patients with stage I and II invasive carcinomas who underwent partial mastectomy were divided into 2 groups based on whether they were treated before (PRE) or after (POST) guideline publication in March 2014. Groups were compared with respect to re-excision rates, conversion to mastectomy, specimen volumes, mean cost per patient of surgical care, and prospectively collected patient post-procedure quality of life.

RESULTS

A total of 237 patients who underwent partial mastectomy were examined (n = 126 in the PRE group and n = 111 in the POST group). Patients in the POST group were less likely to require re-excision (9% POST vs 37% PRE; p < 0.001) and were less likely to undergo conversion to mastectomy (5% POST vs 14% PRE; p = 0.02). After consensus guideline publication, mean operative cost per patient decreased ($4,874 POST vs $5,772 PRE; p < 0.001), and patients had improved breast quality of life scores (77 out of 100 POST vs 61 out of 100 PRE; p = 0.03). On multivariable analysis, publication of the consensus statement was an independent predictor of decreased re-excision rates (odds ratio 0.17; 95% CI 0.08 to 0.38; p < 0.001) and operative cost per patient (odds ratio 0.14; 95% CI 0.78 to 0.30; p < 0.001).

CONCLUSIONS

Widespread implementation of the consensus guideline on margins for breast conserving operation will likely lead to the intended improvements in operative and financial outcomes, as well as patient satisfaction with breast conserving operation.

Breast Specimen Processing and Reporting With an Emphasis on Margin Evaluation: A College of American Pathologists Survey of 866 Laboratories

CONTEXT

- The College of American Pathologists (CAP) developed protocols for reporting pathologic characteristics of breast cancer specimens, including margin status. The Society of Surgical Oncology (SSO) and the American Society for Radiation Oncology (ASTRO) published treatment guidelines regarding margins in patients with invasive cancer; and SSO, ASTRO, and the American Society of Clinical Oncology (ASCO) recently published guidelines for patients with ductal carcinoma in situ.

OBJECTIVE

- To assess current practices among pathologists with regard to the processing/reporting of breast specimens, assess compliance with CAP cancer protocols, and assess alignment with SSO/ASTRO and SSO/ASTRO/ASCO guidelines.

DESIGN

- A survey concerning breast specimen processing/reporting was distributed to pathologists enrolled in the CAP Performance Improvement Program in Surgical Pathology.

RESULTS

- Ninety-four percent (716 of 764 respondents) and 91% (699 of 769 respondents) define positive margins as "tumor on ink" for invasive cancer and ductal carcinoma in situ, respectively, in compliance with CAP cancer protocols and with SSO/ASTRO and SSO/ASTRO/ASCO guidelines. Of 791 respondents who provided details regarding methods for margin evaluation, 608 (77%) exclusively examine perpendicular margins, facilitating guideline compliance. However, 183 of 791 respondents (23%) examine en face margins in at least a subset of specimens, which may preclude guideline compliance in some cases. When separate cavity (shave) margins are examined, while 517 of 586 respondents (88%) ink these specimens, 69 of 586 (12%) do not, and this may also preclude guideline compliance in some cases.

CONCLUSIONS

- A substantial proportion of survey participants report margin status for breast cancer specimens in a manner consistent with CAP cancer protocols, and in alignment with SSO/ASTRO and SSO/ASTRO/ASCO guidelines. However, there are opportunities for some laboratories to modify procedures in order to facilitate more complete adherence to guidelines.

Cost Analysis of a Surgical Consensus Guideline in Breast-Conserving Surgery

BACKGROUND

The Society of Surgical Oncology and American Society of Radiation Oncology consensus statement was the first professional guideline in breast oncology to declare "no ink on tumor" as a negative margin in patients with stages I/II breast cancer undergoing breast-conservation therapy. We sought to analyze the financial impact of this guideline at our institution using a historic cohort.

STUDY DESIGN

We identified women undergoing re-excision after breast-conserving surgery for invasive breast cancer from 2010 through 2013 using a prospectively maintained institutional database. Clinical and billing data were extracted from the medical record and from administrative resources using CPT codes. Descriptive statistics were used in data analysis.

RESULTS

Of 254 women in the study population, 238 (93.7%) had stage I/II disease and 182 (71.7%) had invasive disease with ductal carcinoma in situ. A subcohort of 83 patients (32.7%) who underwent breast-conservation therapy for stage I/II disease without neoadjuvant chemotherapy had negative margins after the index procedure, per the Society of Surgical Oncology and American Society of Radiation Oncology guideline. The majority had invasive ductal carcinoma (n = 70 [84.3%]) and had invasive disease (n = 45 [54.2%]), and/or ductal carcinoma in situ (n = 49 [59.0%]) within 1 mm of the specimen margin. Seventy-nine patients underwent 1 re-excision and 4 patients underwent 2 re-excisions, accounting for 81 hours of operative time. Considering facility fees and primary surgeon billing alone, the overall estimated cost reduction would have been $195,919, or $2,360 per affected patient, under the guideline recommendations.

CONCLUSIONS

Implementation of the Society of Surgical Oncology and American Society of Radiation Oncology consensus guideline holds great potential to optimize resource use. Application of the guideline to a retrospective cohort at our institution would have decreased the overall re-excision rate by 5.6% and reduced costs by nearly $200,000. Additional analysis of patient outcomes and margin assessment methods is needed to define the long-term impact on surgical practice.