Monopolar diathermy versus a vessel-sealing device for reducing postoperative drain output after simple mastectomy: randomized clinical trial

BACKGROUND

Electrosurgical devices are commonly used during mastectomy for simultaneous dissection and haemostasis, and can provide potential benefits regarding vessel and lymphatic ligation. The aim of this prospective RCT was to assess whether using a vessel-sealing device (LigaSure™) improves perioperative outcomes compared with monopolar diathermy when performing simple mastectomy.

METHODS

Patients were recruited prospectively and randomized in a 1 : 1 manner to undergo simple mastectomy using either LigaSure™ or conventional monopolar diathermy at a single centre. The primary outcome was the number of days the drain remained in situ after surgery. Secondary outcomes of interest included operating time and complications.

RESULTS

A total of 86 patients were recruited (42 were randomized to the monopolar diathermy group and 44 were randomized to the LigaSure™ group). There was no significant difference in the mean number of days the drain remained in situ between the monopolar diathermy group and the LigaSure™ group (7.75 days versus 8.23 days; P = 0.613) and there was no significant difference in the mean total drain output between the monopolar diathermy group and the LigaSure™ group (523.50 ml versus 572.80 ml; P = 0.694). In addition, there was no significant difference in the mean operating time between the groups, for simple mastectomy alone (88.25 min for the monopolar diathermy group versus 107.20 min for the LigaSure™ group; P = 0.078) and simple mastectomy with sentinel lymph node biopsy (107.20 min for the monopolar diathermy group versus 114.40 min for the LigaSure™ group; P = 0.440).

CONCLUSION

In this double-blinded single-centre RCT, there was no difference in the total drain output or the number of days the drain remained in situ between the monopolar diathermy group and the LigaSure™ group.

REGISTRATION NUMBER

EudraCT 2018-003191-13 BEAUMONT HOSPITAL REC 18/66.

Multidisciplinary Management of Phyllodes Tumours and Breast Sarcoma: A Cross-sectional Survey of Clinical Practice across the UK and Ireland

AIMS

Phyllodes tumours and breast sarcomas are uncommon tumours and their rarity poses significant challenges in diagnosis and management. This cross-sectional study was conducted to evaluate the multidisciplinary clinical practice for these tumours across the UK and Ireland, with the aim of identifying gaps in knowledge and providing direction for establishing national guidelines.

MATERIALS AND METHODS

An international survey was adapted and circulated to breast and/or sarcoma surgeons and oncologists in the UK and Ireland through national organisations. Multidisciplinary team (MDT) responses were analysed anonymously.

RESULTS

Twenty-eight MDTs participated in this study, predominately from high-volume units (85.5%). Although only 43% of the surveyed units were part of a trust that holds a sarcoma MDT, 68% of units managed malignant phyllodes and angiosarcoma, whereas 64.5% managed soft-tissue sarcoma of the breast. Across all subtypes, axillary surgery was recommended by 14-21% of the MDTs and the most recommended resection margins for breast surgery were 'no tumour on ink' in benign phyllodes (39%) and 10 mm in the remaining subtypes (25-29%). Immediate breast reconstruction was supported by 11-18% of MDTs for breast sarcoma subtypes, whereas 36% and 32% advocated this approach in benign and borderline phyllodes tumours, respectively. Adjuvant radiotherapy and chemotherapy were recommended by up to 29% and 11% of the MDTs, respectively.

CONCLUSION

The results of this study demonstrate a wide variation in clinical practice across the surveyed MDTs. As only 28 MDTs participated in our study, with under-representation from low-volume units, our results might be an underestimation of the variability in practice across the UK and Ireland. This multi-institutional study sheds light on controversial aspects in the management of phyllodes tumours and breast sarcoma, identifies the need for national guidelines to inform best practice, and calls for the centralisation of the management of breast sarcoma within specialist centres.

Efficacy and Safety of Trastuzumab Deruxtecan in Breast Cancer: A Systematic Review and Meta-Analysis

Trastuzumab deruxtecan (T-DXd) is a novel antibody-drug-conjugate (ADC), primarily used in the treatment of HER2-positive breast cancer. This study aimed to conduct a systematic review to evaluate the efficacy and safety of T-DXd in treating breast cancer, based on clinical trials. A systematic search of the literature was conducted to identify clinical trials investigating the efficacy and safety of T-DXd in breast cancer. Clinical trials of any phase were included. Outcome measures were any adverse events and survival. Meta-analysis was conducted where possible. Pooled prevalence for each adverse event of any grade and grade 3 or greater were estimated. Progression-free survival (PFS), overall survival (OS) and objective response rates (ORRs) were also reported to evaluate the efficacy of T-DXd in breast cancer. A total of 1593 patients from 6 clinical trials were included. Common adverse events of any grade were nausea, anemia, neutropenia, vomiting, fatigue, constipation and diarrhea, occurring in greater than 30% of cases. In terms of adverse events of grade 3 or more, only anemia and neutropenia occurred at a relatively high rate. Median PFS ranged from 11.1 to 22.1 months. There was evidence of a benefit of T-DXd compared to controls in terms of both PFS (OR: 0.38; 95% CI: 0.32, 0.45) and OS (OR: 0.61; 95% CI: 0.48, 0.78). ORRs ranged from 37% to 79.9%. The present systematic review shows evidence that T-DXd is a safe and effective agent in the treatment of breast cancer based on currently available data. The most common adverse events affected the blood, lymphatic and gastrointestinal systems. Interstitial lung disease (ILD) is a notable and potentially serious adverse event.

Assessing Mode of Recurrence in Breast Cancer to Identify an Optimised Follow-Up Pathway: 10-Year Institutional Review

BACKGROUND

Breast cancer surveillance programmes ensure early identification of recurrence which maximises overall survival. Programmes include annual clinical examination and radiological assessment. There remains debate around the value of annual clinical exam in diagnosing recurrent disease/second primaries. The aim was to assess diagnostic modalities for recurrent breast cancer with a focus on evaluating the role of annual clinical examination.

PATIENTS AND METHODS

A prospectively maintained database from a symptomatic breast cancer service between 2010-2020 was reviewed. Patients with biopsy-proven recurrence/second breast primary were included. The primary outcome was the diagnostic modality by which recurrences/secondary breast cancers were observed. Diagnostic modalities included (i) self-detection by the patient, (ii) clinical examination by a breast surgeon or (iii) radiological assessment.

RESULTS

A total of 233 patients were identified and, following application of exclusion criteria, a total of 140 patients were included. A total of 65/140 (46%) patients were diagnosed clinically, either by self-detection or clinical examination, while 75/140 (54%) were diagnosed radiologically. A total of 59/65 (91%) of patients clinically diagnosed with recurrence presented to the breast clinic after self-detection of an abnormality. Four (6%) patients had cognitive impairment and recurrence was diagnosed by a carer. Two (3%) patients were diagnosed with recurrence by a breast surgeon at clinical examination. The median time to recurrence in all patients was 48 months (range 2-263 months).

CONCLUSION

Clinical examination provides little value in diagnosing recurrence (< 5%) and surveillance programmes may benefit from reduced focus on such a modality. Regular radiological assessment and ensuring patients have urgent/easy access to a breast clinic if they develop new symptoms/signs should be the focus of surveillance programmes.

Review of the status of neoadjuvant therapy in HER2-positive breast cancer

Purpose

The development of human epidermal growth factor receptor 2 (HER2)-directed therapies has revolutionized the treatment of HER2-positive breast cancer. The aim of this article is to review the continually evolving treatment strategies in the neoadjuvant setting of HER2-positive breast cancer, as well as the current challenges and future perspectives.

Methods

Searches were undertaken on PubMed and Clinicaltrials.gov for relevant publications and trials.

Findings

The current standard of care in high-risk HER2-positive breast cancer is to combine chemotherapy with dual anti-HER2 therapy, for a synergistic anti-tumor effect. We discuss the pivotal trials which led to the adoption of this approach, as well as the benefit of these neoadjuvant strategies for guiding appropriate adjuvant therapy. De-escalation strategies are currently being investigated to avoid over treatment, and aim to safely reduce chemotherapy, while optimizing HER2-targeted therapies. The development and validation of a reliable biomarker is essential to enable these de-escalation strategies and personalization of treatment. In addition, promising novel therapies are currently being explored to further improve outcomes in HER2-positive breast cancer.

Long-term survival in patients with node-positive breast cancer who undergo sentinel lymph node biopsy alone after neoadjuvant chemotherapy: meta-analysis

BACKGROUND

Sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NACT) in patients with breast cancer who are initially node-positive but convert to clinically/radiologically node-negative remains controversial. The primary aim was to assess pooled 5-year disease-free (DFS) and overall (OS) survival for patients who are initially node-positive but have a negative SLNB after NACT, and do not proceed to axillary lymph node dissection (ALND).

METHODS

The study was performed using PRISMA guidelines. A systematic literature search of relevant databases was conducted. The Der Simonian-Laird and Cochran-Mantel-Haenszel methods were used to calculate weighted pooled estimates for OS and DFS for this group compared with patients who had NACT and proceeded to ALND after a negative or positive SLNB.

RESULTS

Seven studies involving 915 patients who had a negative SLNB after NACT were included. Pooled estimates of 5-year DFS and OS in patients with a negative SLNB after NACT were 86 (95 per cent c.i. 82.1 to 90.3) and 93.1 (87.8 to 97.0) per cent respectively. Patients with a positive SLNB who underwent ALND had reduced 5-year DFS (OR 0.49, 95 per cent c.i. 0.35 to 0.69; P < 0.001) and OS (OR 0.41, 0.16 to 1.02; P = 0.06) compared with those who had a negative SLNB after NACT. There were no differences in DFS for patients who had a negative SLNB only compared with those undergoing ALND with a pCR (OR 1.65, 0.71 to 3.79; P = 0.24).

CONCLUSION

Patients who are initially node-positive and who achieve a complete clinical/radiological axillary response after NACT with a subsequent negative SLNB have high rates of DFS and OS after 5 years. Patients with residual disease have significantly reduced DFS and further axillary treatment may still be warranted.

The Impact of Chemotherapy Prescription on Long-Term Survival Outcomes in Early-Stage Invasive Lobular Carcinoma - A Systematic Review and Meta-Analysis

INTRODUCTION

Invasive lobular carcinoma (ILCs) are typically endocrine responsive breast cancers which respond poorly to chemotherapy. The long-term survival advantage of prescribing chemotherapy in such cases remains unclear. To perform a systematic review and meta-analysis assessing, the impact of prescribing chemotherapy in such patients on long-term disease-free (DFS) and overall (OS) survival outcomes.

METHODS

A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. Ten-year DFS and OS were pooled as odds ratios (ORs) with 95% confidence intervals (CI) using the Mantel-Haenszel method. Time-to-effect modelling was performed using the generic inverse variance method.

RESULTS

Overall, 9 studies including 28,218 patients were included. The mean follow-up was 74 months (range: 0-150 months) and mean age was 60 years (range: 22-90 years). Of these, 34.7% received chemotherapy (9,797/28,218) and 66.3% did not receive chemotherapy (18,421/28,218). Chemotherapy prescription failed to improve 10-year DFS (OR: 0.89, 95% CI: 0.65-1.23) and OS (OR: 0.92, 95% CI: 0.72-1.18). When using time-to-effect modelling, chemotherapy prescription failed to improve DFS (hazard ratio (HR): 1.01, 95% CI: 0.78-1.31) and OS (HR: 1.07, 95% CI: 0.89-1.27, I²= 67%).

CONCLUSION

This meta-analysis illustrates no long-term survival advantage associated with chemotherapy prescription in the setting of early-stage ILC. In the absence of well-designed, prospective clinical trials evaluating the impact of chemotherapy on long-term outcomes in ILC, these results should be considered by the multidisciplinary team when deciding on the value of systemic chemotherapy prescription in ILC.

Mapping molecular subtype specific alterations in breast cancer brain metastases identifies clinically relevant vulnerabilities

The molecular events and transcriptional plasticity driving brain metastasis in clinically relevant breast tumor subtypes has not been determined. Here we comprehensively dissect genomic, transcriptomic and clinical data in patient-matched longitudinal tumor samples, and unravel distinct transcriptional programs enriched in brain metastasis. We report on subtype specific hub genes and functional processes, central to disease-affected networks in brain metastasis. Importantly, in luminal brain metastases we identify homologous recombination deficiency operative in transcriptomic and genomic data with recurrent breast mutational signatures A, F and K, associated with mismatch repair defects, TP53 mutations and homologous recombination deficiency (HRD) respectively. Utilizing PARP inhibition in patient-derived brain metastatic tumor explants we functionally validate HRD as a key vulnerability. Here, we demonstrate a functionally relevant HRD evident at genomic and transcriptomic levels pointing to genomic instability in breast cancer brain metastasis which is of potential translational significance.

Highly aggressive neuroendocrine neoplasm of the ascending colon: a wolf in sheep's clothing

Neuroendocrine neoplasms represent a broad group of uncommon tumours, comprising neuroendocrine tumours, mixed neuroendocrine non-endocrine neoplasms and neuroendocrine carcinomas. While most neuroendocrine neoplasms are well differentiated and exhibit indolent disease biology with excellent treatment response, neuroendocrine carcinomas represent a rare subtype with much more aggressive tumour behaviour, minimal response to adjuvant therapy and extremely poor prognosis. Herein, we report the case of a 47-year-old man who presented with a phlegmonous ascending colonic mass and associated calcified ileocolic lymphadenopathy. He underwent emergent right hemicolectomy, which diagnosed a T4aN2b neuroendocrine carcinoma. Within a week the patient displayed rapidly progressive locoregional nodal disease and he succumbed to disease within 5 weeks. We discuss the significance of calcified abdominal lymphadenopathy on computed tomography scans of the abdomen and review the literature surrounding this rare and highly fatal malignancy.

P02.01 A strategy to personalize the use of radiation in patients with brain metastasis based on S100A9-mediated resistance

BACKGROUND

Finding effective treatment options for patients with brain metastasis remains an unmet need. Given the limitations imposed by the blood-brain-barrier for systemic approaches, radiotherapy offers a superior ability to access the brain. While clinical practice recently adapted the use of stereotactic radiosurgery (SRS), Whole-Brain-Radiotherapy (WBRT) continuous to be an important treatment option, since many patients present with multifocal lesions or bad performance scores, rendering them ineligible for SRS. Unfortunately, overall survival of patients remains unaffected by radiotherapy. Despite this clinical data, the molecular mechanisms that allow metastatic cells to resist radiotherapy in the brain is unknown.

MATERIAL AND METHODS

We have applied WBRT to experimental brain metastasis from lung and breast adenocarcinoma and validated their resistance in vivo.

RESULTS

An unbiased search to identify potential mediators of resistance identified the S100A9-RAGE-NFκB-JunB pathway. Targeting this pathway genetically reverts the resistance to radiotherapy and increases therapeutic benefits in vivo. In two independent cohorts of brain metastasis from lung and breast adenocarcinoma patients, levels of S100A9 correlate with the response to radiotherapy, offering a novel approach to stratify patients according to their expected benefit. In order to make this biomarker also available for brain metastasis patients receiving palliative WBRT without preceding surgery, we complemented our tumor-specimen based approach with the less invasive detection of S100A9 from liquid biopsies. Here, serum S100A9 also correlated with a worse response to WBRT in brain metastasis patients. Furthermore, we have validated the use of a blood-brain-barrier permeable RAGE inhibitor to restore radio-sensitivity in experimental brain metastasis models in vivo and in patient-derived organotypic cultures of radio-resistant brain metastasis ex vivo.

CONCLUSION

We identified S100A9 as a major mediator of radio-resistance in brain metastasis and offer the molecular framework to personalize radiotherapy by exploiting it as a biomarker and as a therapeutic target, thus maximizing the benefits for the patient.

Evolving Trends in Surgical Management of Breast Cancer: An Analysis of 30 Years of Practice Changing Papers

The management of breast cancer has evolved into a multidisciplinary evidence-based surgical speciality, with emphasis on conservative surgery. A number of landmark trials have established lumpectomy followed by radiation as the standard of care for many patients. The aim of this study is to construct a narrative review of recent developments in the surgical management of breast cancer and how such developments have impacted surgical practice. A comprehensive literature search of Pubmed was conducted. The latest search was performed on October 31^st, 2020. Search terms “breast cancer” were used in combinations with specific key words and Boolean operators relating to surgical management. The reference lists of retrieved articles were comprehensively screened for additional eligible publications. Articles were selected and reviewed based on relevance. We selected publications in the past 10 years but did not exclude commonly referenced and highly regarded previous publications. Review articles and book chapters were also cited to provide reference on details not discussed in the academic literature. This article reviews the current evidence in surgical management of early-stage breast cancer, discusses recent trends in surgical practice for therapeutic and prophylactic procedures and provides commentary on implications and factors associated with these trends.

RADI-03. A strategy to personalize the use of radiation in patients with brain metastasis based on S100A9-mediated resistance

Finding effective treatment options for patients with brain metastasis remains an unmet need. Given the limitations imposed by the blood-brain-barrier for systemic approaches, radiotherapy offers a superior ability to access the brain. While clinical practice recently adapted the use of stereotactic radiosurgery (SRS), Whole-Brain-Radiotherapy (WBRT) continuous to be an important treatment option, since many patients present with multifocal lesions or bad performance scores, rendering them ineligible for SRS. Unfortunately, overall survival of patients remains unaffected by radiotherapy. Despite this clinical data, the molecular mechanisms that allow metastatic cells to resist radiotherapy in the brain is unknown. We have applied WBRT to experimental brain metastasis from lung and breast adenocarcinoma and validated their resistance in vivo. An unbiased search to identify potential mediators of resistance identified the S100A9-RAGE-NFkB-JunB pathway. Targeting this pathway genetically reverts the resistance to radiotherapy and increases therapeutic benefits in vivo. In two independent cohorts of brain metastasis from lung and breast adenocarcinoma patients, levels of S100A9 correlate with the response to radiotherapy, offering a novel approach to stratify patients according to their expected benefit. In order to make this biomarker also available for brain metastasis patients receiving palliative WBRT without preceding surgery, we complemented our tumor-specimen based approach with the less invasive detection of S100A9 from liquid biopsies. Here, serum S100A9 also correlated with a worse response to WBRT in brain metastasis patients. Furthermore, we have validated the use of a blood-brain-barrier permeable RAGE inhibitor to restore radio-sensitivity in experimental brain metastasis models in vivo and in patient-derived organotypic cultures of radio-resistant brain metastasis ex vivo. In conclusion, we identified S100A9 as a major mediator of radio-resistance in brain metastasis and offer the molecular framework to personalize radiotherapy by exploiting it as a biomarker and as a therapeutic target, thus maximizing the benefits for the patient.

Poor patient awareness of peripheral arterial disease, it is time to optimize the clinical visit

INTRODUCTION

Peripheral arterial disease (PAD) is a growing public health burden. The development and progression of PAD is influenced by vascular risk factor management and lifestyle changes. However, public awareness of PAD is low compared with other conditions such as heart disease and stroke, which have been the subject of widespread public health campaigns. This study aimed to determine current levels of PAD awareness among hospital patients.

METHODS

This cross-sectional, tertiary hospital-based, descriptive study was conducted over 6 months in 2019. Two investigators administered the survey in face-to-face interviews to patients attending 3 different hospital-based settings including vascular clinics (VC), cardiology clinics (CVC), and Emergency Department (ED).

RESULTS

A total of 150 patients were interviewed. Participants demonstrated low overall awareness of vascular disease (32% PAD and 21% AAA) compared to cardiovascular disease including stroke (71%) and myocardial infarction (63%). Awareness of PAD was higher in vascular patients (51%) compared to CVC and ED patients (p=<0.01). Of the total population, 77% and 71% identified the contributory role of smoking and limited exercise to the development of PAD respectively. VC patients were more informed of intermittent claudication (78%) and amputation (80%) (p < 0.01) compared to CVC and ED patients.

CONCLUSION

In the global drive to reduce vascular morbidity, this study highlights the poor knowledge of PAD among the public. In addition, there is poor awareness about the incidence, risk factors and complications of PAD. These results highlight the need for accessible and easily understood information regarding PAD in both the clinic setting and public health campaigns.

O28: M6A DEMETHYLASE FTO A POTENTIAL TARGET IN BRAIN METASTATIC BREAST CANCER

Introduction

Brain metastasis (BrM) occurs in 10-30% of patients with advanced breast cancer (BC). BrM is increasing in incidence and confers a poor prognosis. We aimed to investigate the contribution of global epi-transcriptomic alterations in N6-methyladenosine (m6A) RNA-methylation as a therapeutic target in brain metastatic breast cancer.

Method

In preliminary studies we have demonstrated m6A demethylase – FTO as the main contributor to the progression of ER+ breast cancer. Furthermore an association between FTO and reduced disease-free-survival (n=870, p=0.018) was observed. Here we conducted an epigenetic inhibitor screen using two therapeutic agents, ethyl-ester-meclofenamic acid (MA2) and FB23-2 on matched 2D cell line, 3D organoid cultures and patient-derived xenografts (PDX) explant models of brain metastasis.

Result

Upon integration of mapped global RNA methylation landscape with matched proteomic analysis, we observed genome-wide RNA hypo-methylation of key pluripotency genes, including SOX2 and KLF4, as key players underlying tumour progression to the brain.  Genetic and pharmacological inhibition of FTO in novel ex vivo models of BrM significantly reduced protein expression levels of KLF4 and SOX2. Moreover, pharmacological inhibition of FTO with MA2 and FB23-2, inhibited cell proliferation in endocrine-resistant BC and patient BrM cells. We translate our findings to the clinic by demonstrating the efficacy of anti-FTO therapies in several unique PDX and 3D organoid BrM models.

Conclusion

Our results reveal epi-transcriptional remodelling events as a key mechanism in BrM. This study establishes an early role for targeting RNA methylation in the management of disease progression and presents FTO as a potential therapeutic target in BrM.

Take-home message

This study establishes an early role for targeting RNA methylation in the management of disease progression and presents FTO as a potential therapeutic target in brain metastatic breast cancer.

O30: EVALUATION OF AXILLARY LYMPH NODE METASTATIC BURDEN BY PREOPERATIVE ULTRASOUND

Introduction

Sentinel lymph node biopsy (SLNB) is the gold standard for determining axillary nodal status. There is growing interest in using preoperative axillary ultrasound (AUS) as a non-invasive means of assessing the axilla. However, AUS has limited sensitivity and is subject to operator dependency. This study aimed to quantify axillary nodal burden in preoperative AUS.

Method

This retrospective study used an institutional database of all primary invasive breast carcinomas from 2006–2019. Those with pathologically proven axillary metastatic disease were included. Patients were considered in two groups, low nodal burden/LNB(1-2LN) and high nodal burden/HNB(≥3LN) based on total positive lymph node count(SLNB+ALND). Preoperative AUS reports were assessed to determine those suspicious for axillary metastasis.

Result

Of the 347 patients (n=349 axillae), 77.9% had LNB and 22.1% had HNB. In patients with LNB, 228(83.8%) had a normal AUS versus 44(16.2%) suspicious AUS. In those with HNB 60(77.9%) had normal AUS findings versus 17(22.1%) suspicious findings. On multivariate analysis Nottingham Grade-3 was associated with suspicious AUS findings (p=0.02). However, receptor status, SLN macro-metastasis and extra-nodal extension were not associated with abnormal AUS.

Conclusion

As the surgical approach to the axilla becomes increasingly conservative, detection of axillary involvement by non-invasive means is an area of increasing research. In this cohort, AUS did not reliably identify patients with axillary metastasis. These results highlight the challenges in accurately assessing the axilla using preoperative AUS, which may result in axillary undertreatment if used as an alternative to surgical staging.

Take-home message

As the surgical approach to the axilla becomes increasingly conservative, detection of axillary involvement by non-invasive means is an area of increasing research. This study highlights the challenges in accurately assessing the axilla using preoperative AUS, which may result in axillary undertreatment if used as an alternative to surgical staging.

Breast cancer patients with a negative axillary ultrasound may have clinically significant nodal metastasis

INTRODUCTION

The non-invasive nature of the preoperative axillary ultrasound (AUS) fits the current trend of increasingly conservative axillary management. Recent publications suggest that early disease patients with clinically and radiologically negative axillae do not require sentinel lymph node biopsy (SLNB). This study aims to determine the true extent of axillary node disease in negative preoperative AUS patients.

METHODS

A 10-year breast cancer registry was reviewed to identify women with pathologically confirmed T1-2 invasive breast cancer and a negative preoperative AUS. Patients who received neoadjuvant chemotherapy were excluded. Combined positive lymph node count of SLNB ± ALND was used to determine total nodal burden (TNB). Axillae were classified into low nodal burden (LNB) defined as 1-2 positive nodes and high nodal burden (HNB) defined as ≥ 3 positive nodes.

RESULTS

762 patients with negative AUS were included. There were 46.9% and 53.0% T1 and T2 tumours, respectively. 76.9% were node negative (0 LN +), 18.9% had LNB (1-2 LN +) and 4.2% had HNB (≥ 3LN +). Specifically, HNB disease was seen in 2% of T1 tumours and 6.2 % of T2 tumours with a negative AUS. In multivariate analysis, T2 strongly associated with ≥ 3 positive ALNs (OR 2.66 CI 1.09-6.51 p = 0.03) as did lymphovascular invasion (OR 3.56 CI 1.52-8.30 p =  < 0.01).

CONCLUSION

This study shows that AUS in its current form cannot exclude HNB axillary metastasis to the extent of eliminating the need for surgical staging of the axilla. This may impact axillary local-regional recurrence and disease-free survival. We caution that a negative AUS has a rate of 4.2% of HNB. Therefore, in cases of negative AUS with a T2 tumour, we advocate continued use of SLNB.

Abstract PD13-01: Homologous recombination deficiency represents a new therapeutic strategy for breast cancer brain metastases

BACKGROUND: Brain metastatic disease occurs in 10-30% of metastatic breast cancer cases. The incidence of brain metastases is increasing, yet overall survival remains &lt; 2 years. Treatment of brain metastases is limited with current clinical practice centered on radiation, chemotherapy and surgery. Although these treatments may prolong survival in the short term, targeting oncogenic alterations in brain metastases may deliver a more sustained clinical benefit. In this multicenter study, we comprehensively characterized DNA and RNA alterations that aberrantly drive specific oncogenic pathway activity pertinent to breast cancer brain metastases (BCBM).

METHODS: RNA sequencing was performed on a cohort of patient-matched primary and resected brain metastatic tumours (45 patients; N=90 samples). Whole exome DNA sequencing (WXS) was performed for 18/45 patients (54 trios consisting of primary tumor, brain metastasis and matched normal tissue). An independent brain metastatic WXS cohort (N=21 patients) (PMID: 26410082) was also analysed resulting in a total of 39 patient samples. Recurrent somatic copy number alterations (SCNA), somatic single nucleotide variants (SNVs) and mutational signatures were identified from WXS data. Expressed gene fusions were detected computationally from RNA-Seq (N=45 cases)

RESULTS: Of the 45 BCBM patients, median age at diagnosis was 51 years [25, 67], median overall survival 57 months (range 18-255) with median brain metastases free survival 34 months (range 5-216).Clinical molecular subtype of the primary tumour included 13 ER+/HER2- (29%), 16 HER2+ (35.5%) and 16 TNBC (35.5%). Regions of significant recurrent amplifications and deletions in BCBM (N=39 patients) were identified in 4q12, 10q11.21, 8p11.23, 8q23.3 and 17q12 (FDR &lt; 0.10). Recurrent expressed gene fusions identified in known cancer driver genes were associated with chromatin modification, MAPK and HER signaling pathways. Mutational signature analysis of SNVs identified signatures associated with ageing, mismatch repair and homologous recombination deficiency (HRD) mutational processes. The relative contribution of the HRD signature was significantly increased in brain metastases compared to matched primary tumour (p &lt; 0.05). Concordantly increased HRD in the brain metastatic transcriptome was confirmed in these patients by gene set variation analysis (GSVA) of homologous recombination pathway genes from KEGG database in RNA-Seq data. Moreover, in the extended BCBM RNA-Seq (N=45 patients) GSVA pathway scores were elevated in brain metastases relative to primary tumours, validating the functional significance of altered DNA repair defects in brain metastases

CONCLUSIONS: Here, we report recurrent genetic drivers, supported by altered functional transcriptome, unique to brain metastasis that may have clinical implications for prognosis and treatment choice. Specifically, targeting defects in the homologous recombination repair mechanism may represent new therapeutic strategies and management opportunities for breast cancer brain metastases patients.

Citation Format: Nicola S Cosgrove, Damir Varešlija, Stephen Keelan, Simon Furney, Jodi M Carter, Steven N Hart, Siddhartha Yadav, Arnold DK Hill, Steffi Oesterreich, Adrian V Lee, Fergus J Couch, Leonie Young. Homologous recombination deficiency represents a new therapeutic strategy for breast cancer brain metastases [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD13-01.

ADAM22/LGI1 complex as a new actionable target for breast cancer brain metastasis

BACKGROUND

Metastatic breast cancer is a major cause of cancer-related deaths in woman. Brain metastasis is a common and devastating site of relapse for several breast cancer molecular subtypes, including oestrogen receptor-positive disease, with life expectancy of less than a year. While efforts have been devoted to developing therapeutics for extra-cranial metastasis, drug penetration of blood-brain barrier (BBB) remains a major clinical challenge. Defining molecular alterations in breast cancer brain metastasis enables the identification of novel actionable targets.

METHODS

Global transcriptomic analysis of matched primary and metastatic patient tumours (n = 35 patients, 70 tumour samples) identified a putative new actionable target for advanced breast cancer which was further validated in vivo and in breast cancer patient tumour tissue (n = 843 patients). A peptide mimetic of the target's natural ligand was designed in silico and its efficacy assessed in in vitro, ex vivo and in vivo models of breast cancer metastasis.

RESULTS

Bioinformatic analysis of over-represented pathways in metastatic breast cancer identified ADAM22 as a top ranked member of the ECM-related druggable genome specific to brain metastases. ADAM22 was validated as an actionable target in in vitro, ex vivo and in patient tumour tissue (n = 843 patients). A peptide mimetic of the ADAM22 ligand LGI1, LGI1MIM, was designed in silico. The efficacy of LGI1MIM and its ability to penetrate the BBB were assessed in vitro, ex vivo and in brain metastasis BBB 3D biometric biohybrid models, respectively. Treatment with LGI1MIM in vivo inhibited disease progression, in particular the development of brain metastasis.

CONCLUSION

ADAM22 expression in advanced breast cancer supports development of breast cancer brain metastasis. Targeting ADAM22 with a peptide mimetic LGI1MIM represents a new therapeutic option to treat metastatic brain disease.

Arteriovenous Fistula for dialysis - Let's Google it. Readability and quality of online information

BACKGROUND

This study evaluated the readability and quality of information regarding arteriovenous (AV) fistula for dialysis on the Internet in the English language.

STUDY DESIGN

Using Google© search, the keywords "AV Fistula for dialysis" were searched. The top 75 ranking sites were analyzed. One website was excluded due to repetition. Each landing page was assessed independently by two authors (RB, LR) for readability using the Flesch Reading Ease Score (FRES) and Gunning Fog Index (GFI). Web site quality was assessed using the DISCERN instrument. The individual position of the top 15 websites in the search engine ranking order list was noted. The country of origin, organization type and issuance of Health on the Net (HoN) Certification was recorded. Statistical analyses were performed using unpaired t-tests and ANOVA variance.

RESULTS

The mean GFI score was 9.2 and the mean FRES score was 50.6, indicating poor readability. The mean DISCERN score was 48.4, indicating weak quality of websites. Website quality was influenced by the academic/healthcare organization type (p = 0.012). Organization type was not found to impact GFI and FRES scores. Presence of a HoN Certification was not found to impact the quality of information. The majority of sites originated from the United States (61%).

CONCLUSION

Our study demonstrates that internet information pertaining to AV fistula for dialysis is of poor quality necessitating improvements to readability and overall website quality to improve the patient experience. Further research into how to improve healthcare web information is needed.

Role of echocardiographic left ventricular mass and carotid intima-media thickness in the cardiovascular risk assessment of asymptomatic patients with type 2 diabetes mellitus

BACKGROUND

Standard cardiovascular (CV) risk assessment may underestimate risk in people with type 2 diabetes mellitus (T2DM). Cardiac and vascular imaging to detect subclinical disease may augment risk prediction. This study investigated the association between CV risk, left ventricular hypertrophy (LVH) and carotid intima-media thickness (CIMT) in patients with T2DM free of CV symptoms.

METHODS

People with T2DM without known CV disease were recruited from general practice. The 5-year risk of CV events was calculated using an adjusted Framingham equation and the prevalence of LVH and abnormal CIMT across bands of CV risk assessed. In those at intermediate risk, the number needed to scan (NNS) to reclassify one person to high risk was calculated across the group and compared in those above and below 55 years. The association between LV mass and CIMT was also assessed.

RESULTS

Mean age 57 years (SD11), 51% female. Median 5-year CV risk 14.3% (interquartile range 10.3, 19.5), 51% had LVH (American Society of Echocardiography criteria) and 31% an abnormal CIMT (age and sex criteria). In the 52% at intermediate risk, 37% had LVH and 36% an abnormal CIMT. The NNS was 1.7 using both imaging techniques, 2.7 using cardiac imaging alone or 2.8 using vascular imaging alone. Almost twice as many people >55 years had an abnormal CIMT than those <55 years.

CONCLUSIONS

Cardiac and vascular imaging to detect subclinical disease can be used to augment prediction of CV risk in people with T2DM at intermediate risk. The value of reclassifying risk is as yet unproven and requires outcome data from intervention studies.

Functional MRI in NPSLE patients reveals increased parietal and frontal brain activation during a working memory task compared with controls

OBJECTIVES

Anatomical MRI brain scans may not reflect neurological dysfunction in patients with NPSLE. We used blood-oxygen-level-dependent functional MRI (BOLD-fMRI) to investigate working memory function in NPSLE patients.

METHODS

Twenty-seven females took part: nine NPSLE patients (mean age 40 yrs; SLEDAI 10.9); nine RA patients and nine healthy controls. Subjects were tested using the n-back paradigm for working memory, where patients indicate when a stimulus matches one presented n trials previously. Functional scans used 3 mm slices x 30, repetition time 2570 ms, echo time 50 ms. Echo planar images were superimposed onto T1w anatomical images (Siemens 1.5 T). Data analysis used Brain Voyager QX Version 1.7.

RESULTS

During the memory task, there was activation in areas serving working memory, executive function and attention in all groups. Nine regions of interest were selected for activation during working memory (N-back task vs fixation, P < or = 0.005). In six out of nine regions, there was greater activation in the NPSLE group. This reached significance in three regions: the posterior inferior parietal lobules of both hemispheres [Brodmann area (BA) 7] separately and combined (P = 0.014, 0.016 and 0.004, respectively), and the supplementary motor area (mid-line frontal lobe) (BA32/6; P = 0.032).

CONCLUSIONS

NPSLE patients showed greater frontoparietal activation than the other groups during the memory task, suggesting a greater need to recruit extra cortical pathways, possibly to supplement impaired function of standard pathways.