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

Clinicopathological Predictors of Positive Resection Margins in Breast-Conserving Surgery

BACKGROUND

Ductal carcinoma in situ (DCIS) is associated with risk of positive resection margins following breast-conserving surgery (BCS) and subsequent reoperation. Prior reports grossly underestimate the risk of margin positivity with IBC containing a DCIS component (IBC + DCIS) due to patient-level rather than margin-level analysis.

OBJECTIVE

The aim of this study was to delineate the relative risk of IBC + DCIS compared with pure IBC (without a DCIS component) on margin positivity through detailed margin-level interrogation.

METHODS

A single institution, retrospective, observational cohort study was conducted in which pathology databases were evaluated to identify patients who underwent BCS over 5 years (2014-2019). Margin-level interrogation included granular detail into the extent, pathological subtype and grade of disease at each resection margin. Predictors of a positive margin were computed using multivariate regression analysis.

RESULTS

Clinicopathological details were examined from 5454 margins from 909 women. The relative risk of a positive margin with IBC + DCIS versus pure IBC was 8.76 (95% confidence interval [CI] 6.64-11.56) applying UK Association of Breast Surgery guidelines, and 8.44 (95% CI 6.57-10.84) applying the Society of Surgical Oncology/American Society for Radiation Oncology guidelines. Independent predictors of margin positivity included younger patient age (0.033, 95% CI 0.006-0.060), lower specimen weight (0.045, 95% CI 0.020-0.069), multifocality (0.256, 95% CI 0.137-0.376), lymphovascular invasion (0.138, 95% CI 0.068-0.208) and comedonecrosis (0.113, 95% CI 0.040-0.185).

CONCLUSIONS

Compared with pure IBC, the relative risk of a positive margin with IBC + DCIS is approximately ninefold, significantly higher than prior estimates. This margin-level methodology is believed to represent the impact of DCIS more accurately on margin positivity in IBC.

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.

Economic Impact of Reducing Reexcision Rates after Breast-Conserving Surgery in a Large, Integrated Health System

BACKGROUND

Reexcision after breast-conserving surgery (BCS) is costly for patients, but few studies have captured the economic burden to a healthcare system. We quantified operating room (OR) charges as well as OR time and then modeled expected savings of a reexcision reduction initiative.

METHODS

We performed a retrospective cohort review of all breast cancer patients with BCS between January 1, 2016 and December 31, 2020. Operating room charges of disposable supplies and implants as well as operative time were calculated.

RESULTS

During the 5-year period, the 8804 patients who underwent BCS, 1628 (18.5%) required reexcision. The reexcision cohort was younger (61 vs. 64 years, p < 0.001), more likely to have ductal carcinoma in situ (DCIS) (23.7% vs. 15.2%, p < 0.001), and had larger tumors (T1+T2 73.2% vs. 83.1%, p < 0.001). Reexcision costs represented 39% of total costs, the cost per patient for surgery was fourfold higher for reexcision patients. Reexcision operations comprised 14% of total operating room (OR) time (1848 of 13,030 hours). The reexcision rate for 54 surgeons varied from 7.2-39.0% with 46% (n = 25) having a reexcision rate >20%. A model simulating reducing reexcision rates to 20% or below for all surgeons reduced the reexcision rate to 16.2% overall. Using per procedure data, the model predicted a decrease in reexcision operations by 18% (327 operations), OR costs by 14% ($287,534), and OR time by 11% (204 hours).

CONCLUSIONS

Reexcision after BCS represents 39% of direct OR costs and 14% of OR time in our healthcare system. Modest improvements in surgeon reexcision rates may lead to significant economic and OR time savings.

The Impact of Temporal Variation in Indocyanine Green Administration on Tumor Identification During Fluorescence Guided Breast Surgery

BACKGROUND

On average, 21% of women in the USA treated with Breast Conserving Surgery (BCS) undergo a second operation because of close positive margins. Tumor identification with fluorescence imaging could improve positive margin rates through demarcating location, size, and invasiveness of tumors. We investigated the technique's diagnostic accuracy in detecting tumors during BCS using intravenous indocyanine green (ICG) and a custom-built fluorescence camera system.

METHODS

In this single-center prospective clinical study, 40 recruited BCS patients were sub-categorized into two cohorts. In the first 'enhanced permeability and retention' (EPR) cohort, 0.25 mg/kg ICG was injected ~ 25 min prior to tumor excision, and in the second 'angiography' cohort, ~ 5 min prior to tumor excision. Subsequently, an in-house imaging system was used to image the tumor in situ prior to resection, ex vivo following resection, the resection bed, and during grossing in the histopathology laboratory to compare the technique's diagnostic accuracy between the cohorts.

RESULTS

The two cohorts were matched in patient and tumor characteristics. The majority of patients had invasive ductal carcinoma with concomitant ductal carcinoma in situ. Tumor-to-background ratio (TBR) in the angiography cohort was superior to the EPR cohort (TBR = 3.18 ± 1.74 vs 2.10 ± 0.92 respectively, p = 0.023). Tumor detection reached sensitivity and specificity scores of 0.82 and 0.93 for the angiography cohort and 0.66 and 0.90 for the EPR cohort, respectively (p = 0.1051 and p = 0.9099).

DISCUSSION

ICG administration timing during the angiography phase compared with the EPR phase improved TBR and diagnostic accuracy. Future work will focus on image pattern analysis and adaptation of the camera system to targeting fluorophores specific to breast cancer.

Impact of consensus guidelines for breast-conserving surgery in patients with ductal carcinoma in situ

Background

Consensus guidelines published in 2016 recommended a 2 mm free margin as the standard for negative margins in patients undergoing breast‐conserving surgery (BCS) for ductal carcinoma in situ (DCIS). The goal of the guideline recommendation was standardization of re‐excision practices.

Aims

To evaluate the impact of this consensus guideline on our institutional practices.

Methods

We identified all patients at our institution with pure DCIS who were initially treated with BCS from September 2014 to August 2018 using a prospectively‐maintained institutional database. A retrospective chart review was performed to determine margin status and re‐excision rates during the 2 years before and the 2 years after the guideline was published in order to determine the effect on our re‐excision rates. Close margins were defined as <2 mm.

Results

In the 2 years before the consensus guideline was published, 184 patients with DCIS underwent BCS. Twenty‐six patients had positive margins and 24 underwent re‐excision, including three who had completion mastectomy. Of the remaining 159 patients, 76 had ≥2 mm (negative) margins. The remaining 82 patients had close margins and 48 of these patients (58.5%) underwent re‐excision, including one who had a completion mastectomy. Excluding the patients with positive margins, our re‐excision rate was 30.4% prior to the guideline. In the 2 years after the consensus guideline was published, 192 patients with DCIS underwent initial BCS. Twenty‐four patients had positive margins and 22 underwent re‐excision, including three who had completion mastectomy. Of the remaining 168 patients, 95 patients had ≥2 mm (negative) margins. The remaining 73 patients had close margins and 45 of those patients (61.6%) underwent re‐excision, including six who had completion mastectomy. Excluding the patients with positive margins, our re‐excision rate was 26.8% after the guideline.

Conclusions

Our institution's re‐excision rate did not change significantly during the 2 years before and after the publication of the consensus guideline on adequate margins for patients undergoing BCT for DCIS. Our overall re‐excision rate decreased slightly. However, of the patients who had close margins, a larger proportion underwent re‐excision after the guideline was published. The guideline publication appears to have affected our institutional practices slightly, but not dramatically as many of our surgeons' practices were comparable to the guideline recommendations prior to 2016. We continue to use clinical judgment based on patient and tumor characteristics in deciding which patients will benefit from margin re‐excision.

Risk factors for the presence of residual disease in women after partial mastectomy for invasive breast cancer: A single institution experience

BACKGROUND

We hypothesize that in addition to specimen margin widths other clinical variables may help predict the presence of residual disease in the lumpectomy bed.

METHODS

Patients with Stage I-III invasive breast cancer (BC) who underwent partial mastectomy (PM) and re-excision from July 2010-June 2015 were retrospectively reviewed. Bivariate analyses were conducted using two-sample t-tests for continuous variables and Fisher's Exact tests for categorical variables. A multivariate logistic regression was then performed on significant bivariate analyses variables.

RESULTS

ne-hundred and eighty-four patients were included in our analysis; 47% had residual disease on re-excision, while 53% had no residual disease. Tumor and nodal stage, operation type, type of disease present at margin, and number of positive margins were significantly associated with residual disease. On multivariate logistic regression, DCIS alone at the margin (p = 0.02), operation type (PM with cavity margins) (p = 0.003), and number of positive margins (3 or more) (p < 0.001) remained predictive of residual disease at re-excision.

CONCLUSION

Based on a more comprehensive review of the initial pathology, there are additional factors that can help predict the likelihood of finding residual disease and help guide the surgeon in the decision for re-excision.

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.

Raman spectroscopy for rapid intra-operative margin analysis of surgically excised tumour specimens

Raman spectroscopy, a form of vibrational spectroscopy, has the ability to provide sensitive and specific biochemical analysis of tissue. This review article provides an in-depth analysis of the suitability of different Raman spectroscopy techniques in providing intra-operative margin analysis in a range of solid tumour pathologies. Surgical excision remains the primary treatment of a number of solid organ cancers. Incomplete excision of a tumour and positive margins on histopathological analysis is associated with a worse prognosis, the need for adjuvant therapies with significant side effects and a resulting financial burden. The provision of intra-operative margin analysis of surgically excised tumour specimens would be beneficial for a number of pathologies, as there are no widely adopted and accurate methods of margin analysis, beyond histopathology. The limitations of Raman spectroscopic studies to date are discussed and future work necessary to enable translation to clinical use is identified. We conclude that, although there remain a number of challenges in translating current techniques into a clinically effective tool, studies so far demonstrate that Raman Spectroscopy has the attributes to successfully perform highly accurate intra-operative margin analysis in a clinically relevant environment.

Factors related to re-excision procedures following primary breast-conserving surgery for women with breast cancer in the U.S. Military Health System

BACKGROUND AND OBJECTIVES

Re-excision surgery is undertaken to obtain clear margins after breast-conserving surgery (BCS) for localized breast cancer. This study examines patient and tumor characteristics related to re-excision surgery in the universal-access Military Health System (MHS).

METHODS

Retrospective analysis of patients with pathologically confirmed stage I-III breast cancer between 1998 and 2014 in the Department of Defense Central Cancer Registry and MHS Data Repository-linked databases who received primary BCS. Multivariable stepwise logistic regression methods identified characteristics associated with re-excision surgery (lumpectomy and mastectomy) and conversion to mastectomy, given as adjusted odds ratios (AOR) and 95% confidence intervals (CIs).

RESULTS

Of 7637 women receiving BCS, 26.3% had a re-excision and 9.9% converted to mastectomy. Tumor location, larger tumor size (≥4 cm), and regional lymph node involvement were associated with a greater likelihood of re-excision and mastectomy conversion. Pathology before BCS (AOR, 0.39; 95% CI, 0.35, 0.44 for re-excision) and neoadjuvant treatment (AOR, 0.50; 95% CI, 0.36, 0.69 for re-excision) were associated with a decreased likelihood of these outcomes. Additionally, age, tumor histology, and military-specific variables were associated with mastectomy conversion.

CONCLUSION

Comprehensive preoperative workup, including tumor pathology, may better inform surgical decision-making and reduce re-excision rates.

Surgical margins for borderline and malignant phyllodes tumours

BACKGROUND

Phyllodes tumours represent less than 1% of all UK breast neoplasms. Histological features allow classification into benign, borderline or malignant, which has a significant impact on prognosis and recurrence. Currently, there is no consensus for the optimal surgical excision margin. This systematic review aims to provide a comparative summary of outcomes (local recurrence, metastasis and survival) for borderline and malignant phyllodes tumours resected with either ≥1cm or <1cm margins.

METHODS

MEDLINE and Embase were systematically searched (1990 to July 2019), in line with PRISMA guidelines. Study quality was assessed using the Newcastle-Ottawa scale.

RESULTS

Ten retrospective studies were included (Newcastle-Ottawa scale mean score: 5.6, range: 8-4). Nine reported local recurrence rates, four reported distant metastasis and four reported survival. Meta-analysis pooling demonstrated no statistically significant difference between <1cm and ≥1cm margins in terms of local recurrence rates (relative risk [RR] 1.43, 95% confidence interval [95% CI] 0.70 - 2.93; p=0.33, n=456), distant metastasis (RR 1.93, 95% CI 0.35 - 10.63; p=0.45, n=72) or mortality (RR 1.93, 95% CI 0.42 - 8.77; p=0.40, n=58) for borderline and malignant tumours. Additionally, two studies demonstrated no significant difference in local recurrence for borderline tumours excised with <0.1cm margins compared to ≥1cm.

CONCLUSION

Current evidence suggests that margins <1cm may provide adequate tumour excision. This could enable breast conservation in patients with smaller breast-to-tumour volume ratios, with improved cosmetic outcomes and patient satisfaction. A prospective, multi-institutional trial would be appropriate to further elucidate the safety of smaller margins.

Positive margins (R1) risk factors in breast cancer conservative surgery

Background

The primary goal in conservative breast cancer surgery is the complete excision of the tumor, but at the same time attempting to obtain a satisfactory postoperative esthetic result. The notion of “No Ink on Tumor” that indicates exclusively the presence of tumor cells on the inked surface of the surgical specimen is now the gold standard; however, the problem of the free margin is still a fundamental topic of debate that has not yet found a definitive solution.

Methods

Our retrospective analysis takes into account 1440 patients undergoing breast conservative surgery, from October 2004 to November 2018, all treated at the breast unit of our institution.

Results

Positive margins (R1) rate was 10.2% (147 cases out of 1440). Overall survival was 95% at 5 years and 89% at 10 years. No differences in mortality and local recurrence rate between R0 and R1 patients were found. Half of the R1 patients underwent secondary surgery with enlargement of margins, while in the other half we performed direct mastectomy. Among the analyzed variables, age, histological size, histological type, grading, multifocality, lympho-vascular invasion and lymph node status were significantly correlated with the R1 status. The multivariate analysis shows  the association of age and surgical technique (oncoplastic) with R1 status.

Conclusion

Further studies will allow the creation of a statistical model, for better pre-operative prediction of patients with higher risk of R1 and better selection of patients to be candidates for conservative surgery.

Patient-level costs in margin re-excision for breast-conserving surgery

BACKGROUND

High rates of reoperation following breast-conserving surgery (BCS) for positive margins are associated with costs to healthcare providers. The aim was to assess the quality of evidence on reported re-excision costs and compare the direct patient-level costs between patients undergoing successful BCS versus reoperations after BCS.

METHODS

The study used data from women who had BCS with or without reoperation at a single institution between April 2015 and March 2016. A systematic review of health economic analysis in BCS was conducted and scored using the Quality of Health Economic Studies (QHES) instrument. Financial data were retrieved using the Patient-Level Information and Costing Systems (PLICS) for patients. Exchange rates used were: US $1 = £0·75, £1 = €1·14 and US $1 = €0·85.

RESULTS

The median QHES score was 47 (i.q.r. 32·5-79). Only two of nine studies scored in the upper QHES quartile (score at least 75). Costs of initial lumpectomy and reoperation were in the range US $1234-11786 and $655-9136 respectively. Over a 12-month interval, 153 patients had definitive BCS and 59 patients underwent reoperation. The median cost of reoperations after BCS (59 patients) was £4511 (range 1752-18 019), representing an additional £2136 per patient compared with BCS without reoperation (P < 0·001).

CONCLUSION

The systematic review demonstrated variation in methodological approach to cost estimates and a paucity of high-quality cost estimate studies for reoperations. Extrapolating local PLICS data to a national level suggests that getting BCS right first time could result in substantial savings.

Complete excision with narrow margins provides equivalent local control to wider excision in breast conservation for invasive cancer

Background

Society of Surgical Oncology and American Society for Radiation Oncology guidelines define clear margins in breast-conserving therapy (BCT) as 'no ink on tumour', in contrast to the attainment of margins of at least 1 mm widely practised in the UK. The primary aim of this study was to explore clinical, surgical and tumour-related factors associated with local recurrence after BCT, with a secondary aim of assessing the impact of margin re-excision on the risk of local recurrence.

Methods

Patient demographics, surgical details, tumour characteristics and local recurrence were recorded for consecutive women with BCT undergoing surgery between January 1997 and January 2007. Margins were defined as clear (greater than 1 mm), close (less than 1 mm but no ink on tumour), reaches (ink on tumour) and clear after re-excision.

Results

A total of 1045 women of median age 54 (range 18-86) years were studied. Median follow-up was 89 (range 4-196) months. Local recurrence occurred in 52 patients (5·0 per cent). Ink on tumour was associated with local recurrence (hazard ratio (HR) 4·86, 95 per cent c.i. 1·49 to 15·79; P = 0·009). Risk of local recurrence was the same for close and clear margins (HR 1·03, 0·40 to 2·62; P = 0·954). In women with involved margins, re-excision was still associated with an increased local recurrence risk (HR 2·50, 1·32 to 4·72; P = 0·005). Oestrogen receptor negativity increased risk (HR 2·28, 1·28 to 4·06; P = 0·005).

Conclusion

Adequately excised margins, even when under 1 mm, provide equivalent outcomes to wider margins in BCT. Achieving complete excision at primary surgery achieves the lowest rates of local recurrence.

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.

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.

Current margin practice and effect on re-excision rates following the publication of the SSO-ASTRO consensus and ABS consensus guidelines: a national prospective study of 2858 women undergoing breast-conserving therapy in the UK and Ireland

INTRODUCTION

There is variation in margin policy for breast conserving therapy (BCT) in the UK and Ireland. In response to the Society of Surgical Oncology and American Society for Radiation Oncology (SSO-ASTRO) margin consensus ('no ink on tumour' for invasive and 2 mm for ductal carcinoma in situ [DCIS]) and the Association of Breast Surgery (ABS) consensus (1 mm for invasive and DCIS), we report on current margin practice and unit infrastructure in the UK and Ireland and describe how these factors impact on re-excision rates.

METHODS

A trainee collaborative-led multicentre prospective study was conducted in the UK and Ireland between 1st February and 31st May 2016. Data were collected on consecutive BCT patients and on local infrastructure and policies.

RESULTS

A total of 79 sites participated in the data collection (75% screening units; average 372 cancers annually, range 70-900). For DCIS, 53.2% of units accept 1 mm and 38% accept 2-mm margins. For invasive disease 77.2% accept 1 mm and 13.9% accept 'no ink on tumour'. A total of 2858 patients underwent BCT with a mean re-excision rate of 17.2% across units (range 0-41%). The re-excision rate would be reduced to 15% if all units applied SSO-ASTRO guidelines and to 14.8% if all units followed ABS guidelines. Of those who required re-operation, 65% had disease present at margin.

CONCLUSION

There continues to be large variation in margin policy and re-excision rates across units. Altering margin policies to follow either SSO-ASTRO or ABS guidelines would result in a modest reduction in the national re-excision rate. Most re-excisions are for involved margins rather than close margins.