510 Transitioning to an In-House In-Situ Hybridisation Assay Accelerates Indeterminate HER-2 Lesion Results

Introduction

NICE guidelines 1.6.5 recommend that: ‘HER2 status [should be] available and recorded at the pre-operative multidisciplinary team (MDT) meeting when systemic treatment is discussed,’ to aid decision-making regarding neoadjuvant therapy. However, indeterminate HER2 lesions require additional testing by in-situ hybridisation (ISH). This may lead to delays in treatment decision-making, particularly if the testing is outsourced. Our institution has recently switched to using an in-house ISH assay. We compared time between biopsy and ISH results over two periods before and after the introduction of in-house testing, to assess if this improved the availability of HER-2 results, in line with NICE guidelines.

Method

This audit gained local approval. All breast cancer patients discussed at MDT over a two-month time period before (1/11/18-31/12/18) and after (1/9/20-30/10/20) the introduction of in-house ISH testing were identified retrospectively. The numbers of patients requiring ISH and the median time from biopsy to ISH report were compared in the two groups using the Mann-Whitney U test.

Results

106 cases were analysed before the intervention, 39 (37%) of which required ISH with a median wait time of 30 days (13-87). 90 cases were analysed after the intervention, 13 (14%) of which required ISH with a median wait time of 7 days (5-16) (p < 0.01).

Conclusions

By setting up an in-house ISH assay, we significantly reduced the delay between biopsy and HER2 status result for patients with borderline HER2 results. HER2 status is now available at the pre-operative MDT meeting to optimise treatment decision making, as recommended by NICE.

860 Distal Radius Fracture Management in A DGH Do the Guidelines Fit?

Aim

Distal radial fractures are common injuries within adults at a variety of ages. The best treatment option remains a debated subject. The BOAST guidelines aim to guide the initial management of these fractures in the emergency department we audited against these guidelines in a local district general hospital.

Method

A retrospective audit was performed of adult patients with distal radius fractures who attended in December 2019, at a local district General Hospital. Patients were identified by using the Orthopaedic Take lists. Notes were reviewed for patient demographics, quality of documentation of neurovascular status, documentation of fracture information, including further management.

Results

There were 16 cases identified, 87.5% were female with mean age of 63 with over 56 % in the over 65s category. Only 19% of cases had appropriately documented neurovascular status. 57% were lacking specific documentation of each nerve as per BOAST guidelines, as well as 57% had no documentation of radial pulse. With regards to reductions undertaken in ED only 44% were documented if reduction took place. Of the reductions that were documented 66% documented type of analgesia used. 17% used regional anaesthesia as preferred in BOAST guidelines.

Conclusions

Overall compliance with BOAST guidelines was poor. Several areas to improve were seen, for which the recent launch of a new in-house smartphone application is aimed to improve access to BOAST guidelines. There was great difficulty in achieving the BOAST guidance with regards to the use of regional anaesthesia, nationally most A&E departments reduce these fractures under a haematoma block.

145 Mind the App: A Guide for the Orthopaedic Senior House Officer on Call

Aim

Many senior house officers (SHOs) have little experience in Trauma and Orthopaedics. While junior doctors are encouraged to seek help from the registrar during on call shifts, they are also dependent on a variety of guidelines to assist in the management of common orthopaedic presentations to the Emergency Department. The main issue is that site-specific guidance is not readily accessible on a single platform.

Method

Smartphone and web-based applications were designed summarising the initial management for such conditions for the SHO on-call to use as a quick reference tool. The efficacy of this was evaluated with questionnaires specific to the rating of the application and by two closed loop audits of BOAST standards for the management of distal radius and ankle fractures.

Results

Pre-app implementation questionnaire ratings revealed a mediocre confidence levels and high stress during an on-call shift. Post-app implementation questionnaires demonstrated the app was useful. Future use was recommended use for new SHOs. All responders felt that this would improve stress levels on call. Closed-loop audits for BOAST guidelines for ankle and distal radius fracture management were completed. Improvements were evident for obtaining appropriate radiographs ankle fractures (50.0% vs 77.8%) and positions of manipulated distal radius fractures (80% vs 100%).

Conclusions

This application proved a useful reference tool for junior staff to aid and initiate the management of common orthopaedic presentations to the emergency department. This tool could be used to improve confidence and ensure timely management of patients from the take.

534 Use of Ultrasound by Breast Surgeons Reduces the Need for Wire-Guided Localisation Of Impalpable Breast Tumours By Radiologists

Aim

Ultrasound is increasingly being used by non-radiologists in clinical practice. Currently wire-guided localisation (WGL) of impalpable breast tumours requires the expertise of radiologists but can be uncomfortable and demands significant radiology resource. Furthermore, for logistical reasons at our institution during the COVID pandemic, wires were inserted the day before surgery, resulting in disruption to patients. At our institution, two of eight breast surgeons use ultrasound intraoperatively for localisation of breast lesions, thus obviating the need for a radiologist to localise the lesion for the surgeon. We hypothesise that ultrasound-localisation by surgeons is an effective way to improve patient experience.

Method

We undertook a retrospective review of all patients undergoing wire-guided localisation of impalpable breast tumours between 01/05/20-01/08/20. We retrospectively collected the following data: modality of image-guided insertion (ultrasound versus x-ray), operating surgeon and size of tumour.

Results

48 tumours were excised using WGL. 45 of these relied on ultrasound guidance for insertion. The median lesion size was 17mm, with 30 (62.5%) of lumps being ³10mm in size.

Conclusions

Most impalpable lumps were visualised using ultrasound. The majority of these lumps were >10mm. Surgeons trained in ultrasound did not need localisation by radiologists. If breast surgeons were unanimously trained to use ultrasound for intra-operative localisation, a significant proportion of wires could be avoided, saving cost, radiology time, patient time and improving the patient experience. We argue that ultrasound should be a core part of breast trainees’ curriculum.

529 Safeguarding Skin Grafts: A 21st Century Algorithm for Fixation Techniques

Aim

Effective skin graft fixation is fundamental in preventing sheering forces, seroma and haematoma from compromising graft take. However, determining the ideal method of graft fixation remains a contentious subject. Currently, there is significant variation in fixation techniques used, based not only on clinical requirement, but also surgeon preference. Evidence-based recommendations are necessary to guide the decision-making process.

Method

We undertook a PRISMA-based assessment of the literature to define all fixation techniques and analyse their outcomes. Inclusion and exclusion criteria were composed. A search of Medline and Embase was performed, yielding 399 articles. After abstract screening, 96 were included for qualitative data analysis.

Results

Nine fixation techniques were identified: ‘tie over bolster’, ‘staple fixation’, ‘simple dressings’, ‘quilting sutures’, ‘re-look methods’, ‘foam sponge bolster’, ‘adhesive glues’, ‘negative pressure wound therapy’ and ‘less common techniques. We analyse the available evidence for each technique, identifying 13 studies with level I/II evidence. We summarise the research that underpins these nine categories, proposing an algorithm to facilitate technique selection based on anatomical and patient-specific factors.

Conclusions

An array of skin graft fixation techniques are used in plastic surgery, without clear guidelines. To our knowledge, this is the first time all fixation techniques have been defined. Our suggested algorithm is intended to aid surgeons in selecting an appropriate fixation technique and should be challenged by future research, particularly randomised control trials.

77 Lessons Learnt from Managing Orthopaedic Trauma During the First Wave of the COVID-19 Pandemic at a UK District General Hospital

Background

The Coronavirus disease (COVID-19) pandemic has contributed to over 900,000 deaths worldwide. Hospitals responded by expanding services to accommodate the forecasted rise in COVID-19-related admissions. We describe the effects these changes had on management of orthopaedic trauma and patient outcomes at a district general hospital in Southern England.

Method

Data were extrapolated retrospectively from two separate six-week periods in 2019 and 2020 (1st April - 13th May) using electronic records of patients referred to the orthopaedic team. Soft tissue injuries were included where a confirmed diagnosis was made with radiological evidence. Patients were excluded if no orthopaedic intervention was required. Data were compared between the two time periods.

Results

There were fewer attendances to hospital in 2020 compared with 2019 (178 vs 328), but time from presentation to surgery significantly increased in 2020 (2.94 days vs 4.91 days, p = 0.009). There were fewer operative complications in 2020 (36/145 vs 11/88, p < 0.001). However, ordinal logistic regression analysis found a significantly greater complication severity in 2020 including death (p = 0.039). Complication severity was unrelated to COVID-19 status.

Conclusions

Restructuring of orthopaedic services in response to the COVID-19 pandemic has been associated with significant delays to surgery and higher post-operative complication severity. Our results demonstrate the need for fast-track emergency operative orthopaedic services in UK district general hospitals whilst the COVID-19 pandemic continues.

364 The Cycling Urologist: Effect on PSA, Haematuria, Pudendal Nerve Entrapment and Cyclists Nodules

Aim

Cycle use has vastly increased over the last few years in the UK. The aim of this review was to evaluate the effect of cycling on the common conditions presenting to the urology clinic, in particular those of raised PSA, haematuria, soft tissue lesions (“cyclist nodules”) and pudendal nerve entrapment syndromes.

Method

A PUBMED search of the literature on cycling and genitourinary disorders was performed. The keywords included “Bicycling” AND “Prostate-specific antigen”, “Bicycling” AND “Haematuria”, “Bicycling” AND “Cyclist Nodules”, “Bicycling” AND “Pudendal Nerve Entrapment”.

Results

The literature suggests no significant change in total PSA levels after a bout of cycling, regardless of age. The type of cycling (mountain biking vs. road cycling) does not influence PSA levels. It is possible that the saddle used in cycling may displace the pressure across the perineal and gluteal region to effectively alleviate pressure on the prostate. Haematuria appears to be rare with cycling but has been described. Perineal nodular induration is a very rare - although possibly under diagnosed condition. It is thought to be caused by repetitive micro trauma from contact between the perineum and saddle. Pudendal nerve entrapment (PNE) represents the most common bicycling associated urogenital problem. Numbness in the perineum, penis, scrotum or the buttocks is the most common and most recognised symptom. Genital numbness may occur unrelated to erectile dysfunction (ED) although cycling related ED is invariably associated with genital numbness.

Conclusions

Urology Trainees and Consultants should be aware of how recreational and high-level cycling may result in presentation to the Urology clinic.

Adipocytes disrupt the translational programme of acute lymphoblastic leukaemia to favour tumour survival and persistence

The specific niche adaptations that facilitate primary disease and Acute Lymphoblastic Leukaemia (ALL) survival after induction chemotherapy remain unclear. Here, we show that Bone Marrow (BM) adipocytes dynamically evolve during ALL pathogenesis and therapy, transitioning from cellular depletion in the primary leukaemia niche to a fully reconstituted state upon remission induction. Functionally, adipocyte niches elicit a fate switch in ALL cells towards slow-proliferation and cellular quiescence, highlighting the critical contribution of the adipocyte dynamic to disease establishment and chemotherapy resistance. Mechanistically, adipocyte niche interaction targets posttranscriptional networks and suppresses protein biosynthesis in ALL cells. Treatment with general control nonderepressible 2 inhibitor (GCN2ib) alleviates adipocyte-mediated translational repression and rescues ALL cell quiescence thereby significantly reducing the cytoprotective effect of adipocytes against chemotherapy and other extrinsic stressors. These data establish how adipocyte driven restrictions of the ALL proteome benefit ALL tumours, preventing their elimination, and suggest ways to manipulate adipocyte-mediated ALL resistance.

Long-Term Daily Administration of Aprepitant for the Management of Intractable Nausea and Vomiting in Children With Life-Limiting Conditions: A Case Series

BACKGROUND

Nausea and vomiting is a common symptom in children through their end of life journey. Aprepitant, a NK-1 antagonist, has become a potent weapon in the fight against chemo-induced nausea and vomiting. However, its use in palliative care for refractory nausea and vomiting has been limited due to limited experience or evidence of continuous use. Emerging evidence suggests that continuous use is not only safe, but also effective in patients with nausea and vomiting refractory to multiple lines of antiemetic therapy.

METHODS

We conducted a single centre retrospective chart review of children receiving care from a specialist palliative care team who were given continuous daily aprepitant for nausea and vomiting and were unresponsive to at least two prior lines of antiemetic therapy. Parental reports of the impact of nausea on mobility and feeding were used as proxy efficacy markers. Duration of effect and toxicity was also evaluated.

RESULTS

Ten children (eight with cancer as a primary diagnosis and two with noncancer diagnoses) received continuous aprepitant and all showed resolution of nausea and vomiting and an increased ability to mobilize and tolerate feeds. No adverse events noted.

CONCLUSION

Our review suggests a role for aprepitant in management of refractory nausea and vomiting, demonstrating safety and efficacy. This case series is the first report of aprepitant use in this manner in the paediatric palliative care setting.

OP0090 CLASSIFICATION OF PATIENTS WITH RELAPSING POLYCHONDRITIS BASED ON SOMATIC MUTATIONS IN UBA1

Background:

Somatic mutations in ubiquitin activating enzyme 1 (UBA1) cause a newly defined syndrome known as VEXAS. [1] More than fifty percent of patients currently identified with VEXAS meet diagnostic criteria for relapsing polychondritis (RP).

Objectives:

To determine the prevalence VEXAS within a cohort of patients with RP, to compare their clinical, laboratory, and immunologic features and to develop a clinical algorithm to inform genetic screening for VEXAS among patients with RP.

Methods:

Exome and targeted sequencing of the UBA1 gene was performed in a prospective observational cohort of patients with RP. Clinical and immunological characteristics of patients with RP were compared based on presence or absence of UBA1 mutations. Random forest was used to derive a clinical algorithm to identify patients with UBA1 mutations. Immune populations were quantified by multipanel flow cytometry. Categorical and continuous variables were compared using the chi square or Kruskal-Wallis test. P<0.05 defined statistical significance.

Results:

Seven of 92 patients with RP (7.6%) were confirmed to have UBA1 mutations (VEXAS-RP). Six additional patients with VEXAS-RP from other cohorts were included for subsequent analyses. Patients with VEXAS-RP were all male, older at disease onset, and commonly had fever, ear chondritis, skin involvement, deep vein thrombosis, and pulmonary infiltrates. Patients with RP as compared with VEXAS-RP had a significantly higher prevalence of airway chondritis, costochondritis and tenosynovitis/arthralgias. (Table). Mortality was significantly greater in VEXAS-RP than RP (27% vs 2% p=0.01). Maximum ESR, CRP, and mean corpuscular volume (MCV) values were significantly greater in VEXAS-RP. Absolute monocyte, lymphocyte, and platelet counts were significantly lower in VEXAS-RP. A decision tree based on male sex, MCV>100 fl and Platelet count<200 K/ul classified between VEXAS-RP and RP with 100% sensitivity and 96% specificity.

Table 1.

Clinical Characteristics of patients with RP vs VEXAS-RP

All Patientsn=98RPn=85VEXAS-RPn=13p valueDemographic CharacteristicsRace, White n (%)90 (92)77 (91)13 (100)0.59Sex, Male n (%)26 (27)13 (15)13 (100)<0.0001Age, Symptom onset, years, Median (IQR)38 (30-47)37 (28-43)56 (54-64)<0.0001Clinical SymptomsFever n (%)33 (34)20 (24)13 (100)<0.0001Ear chondritis n (%)61 (62)48 (56)13 (100)0.0015Nose chondritis n (%)83 (85)71 (84)12 (92)0.68Airway chondritis n (%)37 (38)37 (44)0 (0)0.0015Tenosynovitis/arthalgias n (%)83 (85)77 (91)6 (46)0.0005Skin involvement n (%)33 (34)22 (2611 (85)<0.0001Laboratory ValuesESR, mm/hr, median (IQR)12 (6-22)11 (5-19)66.5 (42-110)<0.0001CRP, mg/L, median (IQR)2.9 (0.8-9.6)1.9 (0.6-6.3)17.7 (9.6-99.5)<0.0001Platelet count (k/uL)246(201-299)258 (227-312)145 (100-169)<0.0001MCV fL93.05 (90-98)92.2 (89-95)105 (102-115)<0.0001Absolute lymphocyte count1.6 (1.1-2.3)1.78(1.4-2.4)0.92 (0.5-1.2)<0.0001CT scan abnormalitiesPulmonary infiltrates n (%)16 (16.33)6 (7.06)10 (77)<0.0001ComplicationsDeath n (%)6 (6)3 (4)3 (23)0.029Unprovoked DVT12 (12)4 (5)8 (62)<0.0001

N number; IQR = interquartile range

Conclusion:

Mutations in UBA1 are causal for disease in a subset of patients with RP. These patients are defined by disease onset in the fifth decade of life or later, male sex, ear/nose chondritis and hematologic abnormalities. Early identification is important in VEXAS given the associated high mortality rate.

References:

[1]Beck DB, Ferrada MA, Sikora KA, Ombrello AK, Collins JC, Pei W, Balanda N, Ross DL, Ospina Cardona D, Wu Z et al: Somatic Mutations in UBA1 and Severe Adult-Onset Autoinflammatory Disease. N Engl J Med 2020, 383(27):2628-2638.

Disclosure of Interests:

None declared

Dermal delivery of amitriptyline for topical analgesia

Abstract

Amitriptyline, administered orally, is currently one of the treatment options for the management of neuropathic pain and migraine. Because of the physicochemical properties of the molecule, amitriptyline is also a promising candidate for delivery as a topical analgesic. Here we report the dermal delivery of amitriptyline from a range of simple formulations. The first stage of the work required the conversion of amitriptyline hydrochloride to the free base form as confirmed by nuclear magnetic resonance (NMR). Distribution coefficient values were measured at pH 6, 6.5, 7, and 7.4. Solubility and stability of amitriptyline were assessed prior to conducting in vitro permeation and mass balance studies. The compound demonstrated instability in phosphate-buffered saline (PBS) dependent on pH. Volatile formulations comprising of isopropyl alcohol (IPA) and isopropyl myristate (IPM) or propylene glycol (PG) were evaluated in porcine skin under finite dose conditions. Compared with neat IPM, the IPM:IPA vehicles promoted 8-fold and 5-fold increases in the amount of amitriptyline that permeated at 24 h. Formulations containing PG also appear to be promising vehicles for dermal delivery of amitriptyline, typically delivering higher amounts of amitriptyline than the IPM:IPA vehicles. The results reported here suggest that further optimization of topical amitriptyline formulations should be pursued towards development of a product for clinical investigational studies.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s13346-021-00982-x.

Odontogenic keratocyst located in the retromolar trigone

Odontogenic keratocysts (OKCs) are a commonly occurring, benign cystic intraosseous lesion thought to arise from the cell rests of the dental lamina. Most instances of OKC are commonly found in the posterior aspect of the mandible. In rare instances, there have been reported cases of OKCs arising in the peripheral gingiva, but these cases are few and far between. Rarer still are the few documented cases of OKCs arising in other soft tissues of the mouth. There are many divided opinions on the diagnosis of these lesions and whether they are truly odontogenic in origin, given their location when they are enucleated from a soft tissue area. To the best of our knowledge, we present the first reported case of a patient with a peripheral OKC located in the retromolar trigone. We discuss this unique case and review the current literature on peripheral OKCs.

Predicting the length of stay at admission for emergency general surgery patients a cohort study

Introduction

Predicting length of stay (LOS) is beneficial to patients and the health service. When a prolonged LOS is predicted, it gives the opportunity for focused therapies and allocation of resources to reduce this period. In emergency general surgery (EGS) there has been limited investigation of variables that may be important predictors of LOS. This study examines social characteristics alongside measures of severity of acute illness and co-morbidities in an adult EGS population to establish their contribution to LOS.

Methods

Data were collected prospectively from patients at admission including medical variables, demographics, and therapeutic requirements. The length of hospital admission was measured, and multiple regression analysis was used to identify variables which predicted the LOS.

Results

Data were collected from 105 patients. The regression model gave an R² of 0.34, p = 0.0006. Barthal index (measure of independence in activities of daily living) was a significant predictor of LOS [logworth 1.649, p0.02243]. Housing status and Level of social support both correlated in one-way analysis with LOS.

Conclusion

There are non-surgical variables, measurable at admission which are of significant value in predicting LOS of EGS patients. This warrants further investigation through a larger study to better quantify the contributions of these variables, and establish potential early interventions to reduce the LOS.

•

Barthal Index is a significant predictor of length of stay at admission for patients admitted under EGS.

•

Unstable housing and a lack of social support independently correlate with a longer length of stay.

•

It may be possible to intervene at admission to reduce the length of stay for patients admitted under EGS.

One-year outcomes of percutaneous coronary intervention in native coronary arteries versus bypass grafts in patients with prior coronary artery bypass graft surgery

Background

Patients with prior coronary artery bypass graft (CABG) surgery often require percutaneous coronary intervention (PCI). Data are still limited in regards to the outcomes of native versus graft PCI after CABG.

Methods

We performed a retrospective study in a tertiary reference cardiac centre of consecutive patients who underwent PCI after CABG. The data were collected for patients who underwent either native or graft PCI from January 2008 to December 2018. Major adverse cardiac events (MACE) included death or myocardial infarction (MI) or revascularization. All outcomes were assessed at 1-year after each index procedure.

Results

A total of 445 PCI were performed in 410 patients (209 had native PCI and 201 had graft PCI). The groups of patients with native vessel PCI and graft PCI were statistically comparable regarding their baseline characteristics. In multivariable Cox regression graft PCI relative to native PCI was an independent risk factor for MACE (hazard ratio [HR] 1.818, 95% confidence interval [CI] 1.148–2.878).

Conclusion

Compared with native coronary PCI, bypass graft PCI was significantly associated with higher incidence of MACE at 1-year and this was mainly driven by MI and revascularization.

MACE outcomes

Funding Acknowledgement

Type of funding source: None

Investigation of binary and ternary solvent systems for dermal delivery of methadone

Methadone appears to be a promising candidate for pain management. Previously, we conducted a comprehensive characterization study of methadone base and evaluated the dermal delivery of methadone from various neat solvents. Four solvents, namely d-limonene (LIM), ethyl oleate (EO), Transcutol® P (TC) and octyl salicylate (OSAL), were identified as the optimal neat solvents for skin delivery of the compound. To explore further approaches to improve methadone permeation, the present work investigated a range of binary and ternary vehicles. In vitro permeation studies in porcine skin confirmed that binary systems delivered significantly higher (p < 0.05) amounts of methadone through the skin compared with neat solvents. The highest skin permeation was observed for formulations composed of propylene glycol (PG) and TC. Nine formulations were subsequently examined in human skin. A good correlation (r² = 0.80) for methadone permeation was obtained between porcine ear skin and human skin data. Solvent uptake studies indicated that the presence of PG not only increased methadone permeation but also TC permeation. The drug appears to "track" the permeation of TC. Future studies will expand further the range of potential vehicles for optimal delivery of the drug, that will ultimately to be investigated in clinical studies.

Variation in esophageal anastomosis technique-the role of collaborative learning

Centralization of care has improved outcomes in esophagogastric (EG) cancer surgery. However, specialist surgical centers often work within clinical silos, with little transfer of knowledge and experience. Although variation exists in multiple dimensions of perioperative care, the differences in operative technique are rarely studied. An esophageal anastomosis workshop was held to identify areas of common and differing practice within the operative technique. Surgeons showed videos of their anastomosis technique by open and minimally invasive surgery. Each video was followed by a discussion. Surgeons from 10 different EG cancer centers attended. Eight key technical differences and learning points were identified and discussed: the optimum diameter of the gastric conduit; avoiding ischemia in the gastric conduit; minimizing esophageal trauma; the use of an esophageal mucosal collar; omental wrapping; intraoperative leak testing; ideal diameter of the circular stapler and the growing use of linear stapled anastomoses. The workshop received positive feedback from participants and on 2 years follow-up, 40% stated that they believed that the learning of tips and techniques during the workshop has contributed to lowering their anastomotic leak rate. Many differences exist in surgical technique. The reasons for, and crucially the significance of, these differences must be discussed and examined. Workshops provide a forum for peer-to-peer collaborative learning to reflect on one's own practice and improve surgical technique. These changes can, in turn, generate incremental improvements in patient care and postoperative outcomes.

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.