Superparamagnetic iron oxide(SPIO) is used increasingly in sentinel lymph node(SLN) identification in breast cancer patients. Identification ratios in the upfront setting are comparable to that of radioisotope and blue dye(RI/BD). However, its use in the neoadjuvant(NACT) setting remains under debate. The aim of this study was to assess the outcomes of SPIO in breast cancer patients receiving NACT followed by surgery. A systematic review of major databases was performed. Studies examining SPIO compared to standard of care(RI/BD) for SLN detection after NACT were included. Primary outcomes included individual detection rate(nodal detection) and nodal detection rate (number of nodes detected). Trial Sequential Analysis (TSA) was performed to assess results certainty. Study quality was assessed using the MINORS tool for observational studies. Five studies involving 374 patients were included. Regarding individual detection rate, SPIO was successful in 308/314 patients and RI in 297/314 patients. Pooled individual detection rates for SPIO and RI were 98.1 % vs 94.6 %(weighted Risk Ratio 1.02,95 % CI 0.99,1.05,p = 0.18; I2 = 24.3 %). Four studies examined nodal detection rates. Within these studies, a total of 625 SLNs were retrieved with 569 detected with SPIO and 468 with RI(mean: 2.26 SLN for SPIO and 1.86 for RI) with a respective nodal detection rate of 91.0 % vs 74.9 %(weighted Risk Ratio:1.25,95 % CI 1.06,1.47,p < 0.001; I2 = 89.6). The median MINORS score was 19/24(range 14-24), denoting good quality. In patients treated with NACT, SPIO performed comparably to RI, but seems to identify more SLNs. Routine use of SPIO in the neoadjuvant setting should be considered safe and effective.

IntroductionInvasive lobular carcinoma (ILC) accounts for 5–15% of invasive breast cancers. Typical ILC is oestrogen receptor (ER) positive and human epidermal growth factor receptor 2 (HER2) negative. Atypical biomarker profiles (ER- and HER2+, ER+ and HER2+ or triple negative) appear to differ from typical ILCs. This study compared subtypes of ILC in terms of clinical and pathological parameters, and response to neoadjuvant chemotherapy (NACT) according to biomarker profile.MethodsAll patients with ILC treated in a single centre from January 2005 to December 2020 were identified from a prospectively maintained database. Clinicopathologic and outcome data was collected and analysed according to tumour biomarker profile.ResultsA total of 582 patients with ILC were treated. Typical ILC was observed in 89.2% (n=519) and atypical in 10.8% (n=63). Atypical ILCs were of a higher grade (35% grade 3 vs 9.6% grade 3, p<0.001).A larger proportion of atypical ILC received NACT (31.7% vs 6.9% p <0.001). Atypical ILCs showed a greater response to NACT (mean RCB (Residual Cancer Burden Score) 2.46 vs mean RCB 3.41, p=0.0365), and higher pathological complete response rates (15% vs 0% p= 0.017). Despite this, overall 5-year disease-free survival (DFS) was higher in patients with typical ILC (91% vs 83%, p=0.001).ConclusionsAtypical ILCs have distinct characteristics. They are more frequently of a higher grade and demonstrate a superior response to NACT. Despite the latter, atypical ILCs have a worse 5-year DFS which should be taken into consideration in terms of prognostication and may assist patient selection for NACT.

Purpose Mammographic Density (MD) refers to the amount of fibroglandular breast tissue present in the breast and is an established risk factor for developing breast cancer. The ability to evaluate treatment response dynamically renders neoadjuvant chemotherapy (NACT) the preferred treatment option in many clinical scenarios. Previous studies have suggested that MD can predict patients likely to achieve a pathological complete response (pCR) to NACT. We aimed to determine whether there is a causal relationship between BI-RADS breast composition categories for breast density at diagnosis and the pCR rate and residual cancer burden score (RCB) by performing a retrospective review on consecutive breast cancer patients who received NACT in a tertiary referral centre from 2015 to 2021. Methods The Mann–Whitney U Test was used to test for differences between two independent groups (i.e. those who achieved pCR and those who did not). A binary logistic regression model was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) for an association between the independent variables of molecular subtype, MD, histological grade and FNA positivity and the dependant variable of pCR. Statistical analysis was conducted with SPSS (IBM SPSS for Mac, Version 26.0; IBM Corp). Results 292 patients were included in the current study. There were 124, 155 and 13 patients in the BI-RADS MD category b, c and d, respectively. There were no patients in the BI-RADS MD category a. The patients with less dense breast composition (MD category b) were significantly older than patients with denser breast composition (MD category c, d) ( p = 0.001) and patients who had a denser breast composition (MD category d) were more likely to have ER+ tumours. There was no significant difference in PgR status, HER2 status, pathological complete response (pCR), FNA positivity, or RCB class dependent upon the three MD categories. A binary logistic regression revealed that patients with HER2-enriched breast cancer and triple-negative breast cancer are more likely to achieve pCR with an OR of 3.630 (95% CI 1.360–9.691, p = 0.010) and 2.445 (95% CI 1.131–5.288, p = 0.023), respectively. Conclusion Whilst dense MD was associated with ER positivity and these women were less likely to achieve a pCR, MD did not appear to independently predict pCR post-NACT.

540 Background: Treatment of hormone receptor positive (HR+) ESBC is evolving. The use of chemotherapy (CT) is declining with use of the 21-gene RS assay. This validated tool predicts the likelihood of adjuvant CT benefit in HR+ ESBC. Results from the TAILOR-x study suggest up to 70% of HR+ node negative ESBC patients (pts) may avoid CT with RS ≤25. Our objectives were to assess the clinical and economic impact of RS testing on treatment decisions using real-world data. Methods: From October 2011 to February 2019, a retrospective, cross-sectional observational study was conducted of HR+ node negative ESBC pts who had RS testing in Ireland. A survey of Irish breast medical oncologists provided the assumption for the decision impact analysis that grade (G) 1 pts would not receive CT pre RS testing and G2/3 pts would receive CT. Using TAILOR-x results, pts were classified low risk (RS ≤ 25) and high risk (RS > 25). Data was collected via electronic patient records. Descriptive statistics were used. Cost data was obtained via the National Healthcare Pricing Regulatory Authority. The economic analysis was adjusted for changing treatment and assay costs over the study period. Results: 963pts were identified. Mean age 56 years. Mean tumour size 1.87cm. 114 (11.8%), 636(66%), 211(22%), 2(0.2%) pts had G1, G2, G3 and unknown G respectively (resp). 797pts (82.8%) had low RS, 159 (16.5%) had high RS, and 7pts(0.7%) unknown RS. 251pts(26%) were aged < 51 at diagnosis. Of these, 45(17.9%), 145(57.8%), 58(23%), 3(1.2) had G1, G2, G3 and unknown G resp. 208pts(82.9%) had RS ≤ 25, 39pts(15.5%) had RS > 25 and 4pts(1.6%) unknown RS. In the RS ≤ 25 group, 111pts(44%) had RS 0-15, 59(23.5%) had RS16-20, and 38(15.1%) had RS21-25. Post RS testing 595pts(61.8%) had a change in CT decision; 586 changed to hormone therapy (HT) alone, and 9 from HT to CT. In total, 227pts(23.5%) received CT, and 3pts(0.3%) declined. Of pts treated with CT; 9(4%) had RS 0-15, 89(39.2%) had RS16-25, 129(56.8%) had RS > 25. The most common CT regimen was docetaxel and cyclophosphamide(TC), administered to 121pts(53%). RS assay use achieved a 69% change in treatment decision among G2/3 pts and a net 61% reduction in CT use. This resulted in savings of over €4 million in treatment costs. Deducting the assay cost, net savings of over one million euro was achieved. Conclusions: Ireland was the first public healthcare system to approve reimbursement for RS testing. Over the 8 year period of the study, a net 61% reduction in CT use in Irish pts with HR+ ESBC was achieved with conservative net savings of over €1,000,000.

Abstract Background . While hormone receptor-positive (HR+), HER 2-negative (HER2-), node-negative breast cancer is associated with an excellent overall prognosis, it possesses a unique penchant for late recurrence. Estimating breast cancer recurrence has traditionally relied on clinicopathologic markers, such as those underpinning the Clinical Treatment Score Post 5 years (CTS5) but there is an increasing dependence on multigene molecular signatures such as the Oncotype DX 21-gene recurrence score (ODX-RS). The purpose of this current study was to examine the relationship between the novel CTS5 and the ODX-RS with an observational cohort study. Methods . The CTS5 and ODX-RS were calculated for 1,358 patients who were diagnosed with HR+, HER2-VE, node-negative, invasive breast cancer. The cohort was split according to menopausal status as defined by age. 381 pre-menopausal (<52 years) and 977 post-menopausal (≥ 52 years) patients were included in the analysis. Correlation statistics were used to investigate the relationship between the CTS5 and the ODX-RS. Results . Considering the CTS5 and ODX-RS as categorical and continuous variables respectively, there was a significant relationship between the CST5 and the ODX-RS categories (Pearson's chi-squared ( x 2 ) p <0.001), and a high ODX-RS was weakly associated with a high CTS5 RS (Pearson product moment correlation pre-menopausal r=0.274, p<0.05; post-menopausal r=0.222, p<0.05). Conclusion. The current study demonstrates a weak but statistically significant correlation between the CTS5 and the ODX-RS that is independent of age. This finding mirrors previous research which indicates that the ODX-RS is poorly correlated with traditional clinicopathologic features used to predict recurrence risk.

Introduction: The Oncotype DX recurrence score (RS) predicts the benefits of adjuvant chemotherapy in oestrogen receptor (ER) positive, HER2-negative breast cancer. Performing an Oncotype DX RS on core biopsy to predict response to neoadjuvant chemotherapy has not been well established. This systematic review aimed to determine if Oncotype DX RS performed on core biopsy at diagnosis predicted pathological complete response (pCR) to neoadjuvant chemotherapy.

BACKGROUND:A recurrence score based on a 21-gene expression assay predicts the benefit of adjuvant chemotherapy in oestrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. This systematic review aimed to determine whether the 21-gene expression assay performed on core biopsy at diagnosis predicted pathological complete response (pCR) to neoadjuvant chemotherapy.METHODS:The study was performed according to PRISMA guidelines. Relevant databases were searched to identify studies assessing the value of the 21-gene expression assay recurrence score in predicting response to neoadjuvant chemotherapy in patients with breast cancer. The Newcastle-Ottawa Scale was used to assess the quality of the studies. Results are reported as risk ratio (RR) with 95 per cent confidence interval using the Cochrane-Mantel-Haenszel method for meta-analysis. Sensitivity analyses were carried out where appropriate.RESULTS:Seven studies involving 1744 patients reported the correlation between pretreatment recurrence score and pCR. Of these, 777 patients (44.6 per cent) had a high recurrence score and 967 (55.4 per cent) a low-intermediate score. A pCR was achieved in 94 patients (5.4 per cent). The pCR rate was significantly higher in the group with a high recurrence score than in the group with a low-intermediate score (10.9 versus 1.1 per cent; RR 4.47, 95 per cent c.i. 2.76 to 7.21; P < 0.001). A significant risk difference was observed between the two groups (risk difference 0.10, 0.04 to 0.15; P = 0.001).CONCLUSION:A high recurrence score is associated with higher pCR rates and a low-intermediate recurrence score may indicate chemoresistance. Routine assessment of recurrence score by the 21-gene expression assay on core biopsy might be of value when considering neoadjuvant chemotherapy in patients with ER-positive, HER2-negative breast cancer.

Abstract Introduction Recent studies have suggested that sentinel lymph node biopsy (SLNB) can be omitted in newly diagnosed elderly breast cancer (BC) patients as it may not influence decisions regarding further therapeutic intervention. The aim of this study was to assess the impact of SLNB on further surgical intervention as well as adjuvant treatments in patients over the age of 80. Method A retrospective study was performed involving all BC patients over the age of 80 diagnosed between 2008 and 2017 who underwent SLNB as part of their initial surgery. Patient/tumour characteristics and adjuvant treatments were recorded. Result 127 patients underwent SLNB in the study period. The median age was 82 (Range: 80-95). 91/127 (71.6%) had ductal pathology, median tumour grade was 2, and oestrogen receptor positivity was seen in 89% of patients. The median number of sentinel nodes removed was 2 (Range: 1-6). 45 patients (35.4%) had a positive sentinel node (median positive nodes = 1). Of the 45 patients, 11 proceeded to axillary lymph node dissection (ALND) (11/127; 8.6%). The median number of nodes excised during ALND was 14 (Range:7-25) and 6 patients (6/11) had further positive nodes. 9% of patients with a positive node received adjuvant chemotherapy, 87% received adjuvant radiotherapy and 79% received hormonal therapy. Conclusion Although SLNB positivity is still used in the elderly patients, only a few patients (<10%) proceed to ALND or receive adjuvant chemotherapy. Hence performing a SLNB should be carefully considered when treating patients over the age of 80 Take-home message The use of SLNB in elderly patients needs to be considered in node negative patients

The association between immediate breast reconstruction (IBR)-related wound complications and breast cancer recurrence (BCR) remains uncertain. This study aimed to investigate the oncological outcomes in patients with wound complications following mastectomy and IBR. A comprehensive search was undertaken for all studies describing complications in patients with breast cancer following IBR. Studies were included if they reported on complications and investigated their relationship with BCR. A meta-analysis was performed using a random-effects model, with data presented as odds ratios and 95% confidence intervals. A total of 1418 patients from five studies were included in the final analysis. The mean age of patients included was 47.2 years. A total of 382 (26.9%) patients had postoperative complications following a majority of implant-based IBR (929/1418). A total of 158 (11.1%) recurrences, which included 63 locoregional and 106 distant recurrences, was noted at a mean follow-up of 66 months. Although there was an increase in recurrence rates in the complication group (n = 66/382; 17.3% vs. n = 92/1036; 8.9%), there was no significant association between complications and BCR (17.3% vs. 8.9%; P = .18) or mortality (3.6% vs. 2.3%; P = .15). Time to adjuvant therapy was significantly increased in patients with complications (mean difference, 8.69 days; range, 1.18-16.21 days; P = .02; I-2 = 0.02). This meta-analysis demonstrated a higher incidence of wound complications following IBR and a statistically significant increased time to adjuvant therapy. However, this did not translate into adverse oncological outcomes in patients with breast cancer undergoing IBR. (C) 2020 Elsevier Inc. All rights reserved.

INTRODUCTION:Although close radial margins after breast-conserving surgery routinely undergo re-excision, appropriate management of patients with close anterior margins remains a topic of controversy. An increasing body of literature suggests that re-excision of close anterior margins yields low rates of residual malignancy and may only be necessary in selected patients. The aim of this study was to examine the management of close anterior margins after breast conserving surgery in a single institution and to analyse the rate of residual disease in re-excised anterior margins.METHODS:All patients having breast conserving surgery at St Vincent's University Hospital from January 2008 to December 2012 were reviewed retrospectively. Data collected included patient demographics, tumour characteristics, margin positivity, re-excision rates and definitive histology of the re-excision specimens. A close margin was defined as les than 2 mm.RESULTS:A total of 930 patients were included with an average age of 65 years (range 29-94 years). Of these, 121 (13%) had a close anterior margin. Further re-excison of the anterior margin was carried out in 37 patients (30.6%) and a further 16 (13.2%) proceeded to mastectomy. Residual disease was found in 18.5% (7/36) of those who underwent re-excision and 7/16 (43.75%) of those who underwent mastectomy. Overall, 11.57% (14/121) of patients with close anterior margins were subsequently found to have residual disease.CONCLUSION:The low yield of residual disease in re-excised anterior margins specimens supports the concept that routine re-excision of close anterior margins is not necessary. Further research is required to definitively assess its influence on the risk of local recurrence.

Background: The prognostic significance of axillary lymph node metastases in patients with breast cancer has long been established. Despite advances in the molecular profiling of breast cancers, nodal status remains an important determinant of treatment. The aim of this study was to identify the diagnostic yield from staging CT of the thorax, abdomen and pelvis (CT-TAP) prompted by the finding of axillary nodal metastases on sentinel lymph node biopsy (SLNB). Methods: A retrospective review over a 5-year period from 2013 to 2017 was performed to identify patients with a positive SLNB who proceeded to undergo a staging CT-TAP, based on multidisciplinary team (MDT) recommendation. Findings on CT were recorded from radiology records and correlated with final pathological stage. Results: In the 5-year study period, 255 patients were included who underwent staging CT-TAP following a positive SLNB. A total of 72 patients had a final pathological nodal status of micro-metastatic disease (pN1mi). None of these patients were shown to have distant metastatic disease on CT. Two patients had incidental findings of synchronous primary tumours. In contrast, the rate of incidental findings requiring additional surveillance was considerable. A total of 32 of the patients with pN1mi (44%) had incidental lung nodules, the majority of which require follow up. In patients with ≥ pN1 disease, distant metastases were identified in 2 patients. Conclusions: The yield from systemic staging CT-TAP in patients with low volume axillary nodal metastases is low, especially for micro-metastatic disease and comes at a high opportunity cost, based on the need for surveillance of incidental findings.

Objective: Recent literature has highlighted concerns regarding the risk of recurrence following minimally invasive parathyroidectomy (MIP) when intra-operative PTH is not utilised. Despite this, it remains the gold standard for treatment of patients with primary hyperparathyroidism (PHPT) and radiologically localised disease. The aim of this study is to assess the role of the percentage drop in the early post-operative PTH to predict patients undergoing MIP at risk of persistent or recurrent disease.