The Prognostic Value of CD39 as a Marker of Tumor-Specific T Cells in Triple-Negative Breast Cancer in Asian Women.

Triple-negative breast cancer (TNBC) has a poor prognosis with limited therapeutic options available for affected patients. Efforts are ongoing to identify surrogate markers for tumor-specific CD8+ T cells that can predict the response to immune checkpoint inhibitor (ICI) therapies, such as programmed cell death protein 1 or programmed cell death ligand-1 blockade. We have previously identified tumor-specific CD39+CD8+ T cells in non-small cell lung cancer that might help predict patient responses to programmed cell death protein 1 or programmed cell death ligand-1 blockade. Based on this finding, we conducted a comparative interrogation of TNBC in an Asian cohort to evaluate the potential of CD39 as a surrogate marker of tumor-specific CD8+ T cells. Using ICI-treated TNBC mouse models (n = 24), flow cytometric analyses of peripheral blood mononuclear cells and tumor-infiltrating lymphocytes revealed that >99% of tumor-specific CD8+ T cells also expressed CD39. To investigate the relationship between CD39+CD8+ T-cell density and CD39 expression with disease prognosis, we performed multiplex immunohistochemistry staining on treatment-naive human TNBC tissues (n = 315). We saw that the proportion of CD39+CD8+ T cells in human TNBC tumors correlated with improved overall survival, as did the densities of other CD39+ immune cell infiltrates, such as CD39+CD68+ macrophages. Finally, increased CD39 expression on CD8+ T cells was also found to predict the response to ICI therapy (pembrolizumab) in a separate cohort of 11 TNBC patients. These findings support the potential of CD39+CD8+ T-cell density as a prognostic factor in Asian TNBC patients.

Mapping the cited evidence of ductal carcinoma in situ from the 5th edition of the World Health Organisation classification of tumours of the breast.

AIMS: Ductal carcinoma in situ (DCIS) is recognised by the World Health Organisation (WHO) Classification of Tumours (WCT) as a non-invasive neoplastic epithelial proliferation confined to the mammary ducts and lobules. This report categorises the references cited in the DCIS chapter of the 5th edition of the WCT (Breast Tumours) according to prevailing evidence levels for evidence-based medicine and the Hierarchy of Evidence for Tumour Pathology (HETP), identifying potential gaps that can inform subsequent editions of the WCT for this tumour. METHODS AND RESULTS: We included all citations from the DCIS chapter of the WCT (Breast Tumours, 5th edition). Each citation was appraised according to its study design and evidence level. We developed our map of cited evidence, which is a graphical matrix of tumour type (column) and tumour descriptors (rows). Spheres were used to represent the evidence, with size and colour corresponding to their number and evidence level respectively. Thirty-six publications were retrieved. The cited literature in the DCIS chapter comprised mainly case series and were regarded as low-level. We found an unequal distribution of citations among tumour descriptors. 'Pathogenesis' and 'prognosis and prediction' contained the most references, while 'clinical features', 'aetiology' and 'diagnostic molecular pathology' had only a single citation each. 'Prognosis and prediction' had the greatest proportion of moderate- and high-levels of evidence. CONCLUSION: Our findings align with the disposition for observational studies inherent in the field of pathology. Our map is a springboard for future efforts in mapping all available evidence on DCIS, potentially augmenting the editorial process and future editions of WCTs.

Early Triple-Negative Breast Cancers in a Singapore Cohort Exhibit High PIK3CA Mutation Rates Associated With Low PD-L1 Expression.

Mutations in the PI3K pathway, particularly PIK3CA, were reported to be intimately associated with triple-negative breast cancer (TNBC) progression and the development of treatment resistance. We profiled PIK3CA and other genes on 166 early-stage TNBC tumors from Singapore for comparison to publicly available TNBC cohorts. These tumors were profiled transcriptionally using a NanoString panel of immune genes and multiplex immunohistochemistry, then manually scored for PD-L1-positivity using 2 clinically relevant clones, SP142 and 22C3. We discovered a higher rate of PIK3CA mutations in our TNBC cohort than in non-Asian cohorts, along with TP53, BRCA1, PTPN11, and MAP3K1 alterations. PIK3CA mutations did not affect overall or recurrence-free survival, and when compared with PIK3CAWT tumors, there were no differences in immune infiltration. Using 2 clinically approved antibodies, PIK3CAmut tumors were associated with PD-L1 negativity. Analysis of comutation frequencies further revealed that PIK3CA mutations tended to be accompanied by MAP kinase pathway mutation. The mechanism and impact of PIK3CA alterations on the TNBC tumor immune microenvironment and PD-L1 positivity warrant further study.

Tertiary lymphoid structures in breast ductal carcinoma in situ correlate with adverse pathological parameters.

AIMS: To investigate tertiary lymphoid structures (TLSs) in ductal carcinoma in situ (DCIS) of the breast and their correlation with pathological features, immune cell markers and clinical outcomes. METHODS AND RESULTS: Morphological identification of TLSs in 198 DCIS cases incorporated B and T cell zones with high endothelial venules. TLS positivity was defined as ≥ 1 TLSs in lesional areas, while TLS area percentage was divided into two categories: low (TLSs < 5%) and high (TLSs ≥ 5%). Previously reported biomarkers included ER, PR, HER2, CD68, CD163, CD4, CD8 and PD-L1. TLSs were observed in 24.7% (49 of 198) of cases, with a mean diameter of 0.44 mm (median = 0.4 mm, range = 0.12-1.43 mm). TLSs were significantly associated with higher nuclear grade, presence of necrosis, hormone receptor negativity/HER2 positivity, triple negativity, tumour infiltrating lymphocytes (TILs) and immune related biomarkers such as FOXP3, CD163, CD4 and CD4/CD8 ratio (all P < 0.05). There were no significant associations between TLSs and recurrence, but a combination of TLSshigh with FOXP3+ , CD4high , CD4/CD8 ratiohigh and CD68high individually, compared with all other combinations, disclosed significantly poorer disease-free survival (DFS) for ipsilateral invasive recurrence (IIR) on both Kaplan-Meier and multivariable Cox regression analyses (all P < 0.05). CONCLUSIONS: TLSs in DCIS were associated with unfavourable prognostic features, TILs and immune cell markers in our study. TLSshigh /FoxP3+ , TLSshigh /CD4high , TLSshigh /(CD4/CD8) ratiohigh and TLSshigh /CD68high were independent factors for poorer DFS for IIR. Further exploration of the pathological significance of TLSs may provide a clinical basis for their recognition as an important structure and functional unit in the tumour immune microenvironment.

Phyllodes tumour evidence gaps mapped from the 5th edition of the WHO classification of tumours of the breast.

AIMS: Breast phyllodes tumours (PTs) are a rare subset of fibroepithelial neoplasms categorised into benign, borderline, and malignant grades according to the World Health Organization (WHO) Classification of Tumours (WCTs). In this report, we developed an evidence gap map (EGM) based on the literature cited in the PT chapter of the 5th edition of the breast WCT in order to identify knowledge and research gaps in PT. METHODS: A framework was first established where the dimensions of the EGM were defined as categories of tumour descriptors, tumour types, and evidence levels. Citations were collected into a Microsoft Excel form and imported into EPPI-reviewer to produce the EGM. RESULTS: The EGM showed that the "Histopathology" and "Pathogenesis" sections contained the most citations, the majority being of low-level evidence. The highest number of citations considered of moderate-level evidence were found in the "Histopathology" section. There was no high-level evidence cited in this chapter. The "Localisation", "Aetiology", and "Staging" sections had the fewest citations. CONCLUSION: This EGM provides a visual representation of the cited literature in the PT chapter of the breast WCT, revealing the lack of high-level evidence citations. There is an uneven distribution of references, probably due to citation practices. Pockets of low-level evidence are highlighted, possibly related to referencing habits, lack of relevant research, or the belief that the information presented is standard accepted fact, without the need for specific citations. Future work needs to bridge evidence gaps and broaden citations beyond those in the latest WCT.

Artificial intelligence modelling in differentiating core biopsies of fibroadenoma from phyllodes tumor.

Breast fibroepithelial lesions (FEL) are biphasic tumors which consist of benign fibroadenomas (FAs) and the rarer phyllodes tumors (PTs). FAs and PTs have overlapping features, but have different clinical management, which makes correct core biopsy diagnosis important. This study used whole-slide images (WSIs) of 187 FA and 100 PT core biopsies, to investigate the potential role of artificial intelligence (AI) in FEL diagnosis. A total of 9228 FA patches and 6443 PT patches was generated from WSIs of the training subset, with each patch being 224 × 224 pixel in size. Our model employed a two-stage architecture comprising a convolutional neural network (CNN) component for feature extraction from the patches, and a recurrent neural network (RNN) component for whole-slide classification using activation values from the global average pooling layer in the CNN model. It achieved an overall slide-level accuracy of 87.5%, with accuracies of 80% and 95% for FA and PT slides respectively. This affirms the potential role of AI in diagnostic discrimination between FA and PT on core biopsies which may be further refined for use in routine practice.

Investigation of three clusters of COVID-19 in Singapore: implications for surveillance and response measures.

BACKGROUND: Three clusters of coronavirus disease 2019 (COVID-19) linked to a tour group from China, a company conference, and a church were identified in Singapore in February, 2020. METHODS: We gathered epidemiological and clinical data from individuals with confirmed COVID-19, via interviews and inpatient medical records, and we did field investigations to assess interactions and possible modes of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Open source reports were obtained for overseas cases. We reported the median (IQR) incubation period of SARS-CoV-2. FINDINGS: As of Feb 15, 2020, 36 cases of COVID-19 were linked epidemiologically to the first three clusters of circumscribed local transmission in Singapore. 425 close contacts were quarantined. Direct or prolonged close contact was reported among affected individuals, although indirect transmission (eg, via fomites and shared food) could not be excluded. The median incubation period of SARS-CoV-2 was 4 days (IQR 3-6). The serial interval between transmission pairs ranged between 3 days and 8 days. INTERPRETATION: SARS-CoV-2 is transmissible in community settings, and local clusters of COVID-19 are expected in countries with high travel volume from China before the lockdown of Wuhan and institution of travel restrictions. Enhanced surveillance and contact tracing is essential to minimise the risk of widespread transmission in the community. FUNDING: None.

Regional registration of whole slide image stacks containing major histological artifacts.

BACKGROUND: High resolution 2D whole slide imaging provides rich information about the tissue structure. This information can be a lot richer if these 2D images can be stacked into a 3D tissue volume. A 3D analysis, however, requires accurate reconstruction of the tissue volume from the 2D image stack. This task is not trivial due to the distortions such as tissue tearing, folding and missing at each slide. Performing registration for the whole tissue slices may be adversely affected by distorted tissue regions. Consequently, regional registration is found to be more effective. In this paper, we propose a new approach to an accurate and robust registration of regions of interest for whole slide images. We introduce the idea of multi-scale attention for registration. RESULTS: Using mean similarity index as the metric, the proposed algorithm (mean ± SD [Formula: see text]) followed by a fine registration algorithm ([Formula: see text]) outperformed the state-of-the-art linear whole tissue registration algorithm ([Formula: see text]) and the regional version of this algorithm ([Formula: see text]). The proposed algorithm also outperforms the state-of-the-art nonlinear registration algorithm (original: [Formula: see text], regional: [Formula: see text]) for whole slide images and a recently proposed patch-based registration algorithm (patch size 256: [Formula: see text] , patch size 512: [Formula: see text]) for medical images. CONCLUSION: Using multi-scale attention mechanism leads to a more robust and accurate solution to the problem of regional registration of whole slide images corrupted in some parts by major histological artifacts in the imaged tissue.

Higher densities of tumour-infiltrating lymphocytes and CD4+ T cells predict recurrence and progression of ductal carcinoma in situ of the breast.

AIMS: Host immunity influences cancer progression and therapeutic response. We investigated the potential of tumour-infiltrating lymphocytes (TILs) around ductal carcinoma in situ (DCIS) in predicting recurrence and progression. METHODS AND RESULTS: CD4, CD8, programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) expression in DCIS from 198 patients was determined by immunohistochemistry. We correlated disease-free survival (DFS), clinicopathological parameters and biomarker expression with TIL density and CD4/CD8 ratio. High TIL density was associated with high nuclear grade (P < 0.001), DCIS PD-L1 expression (P = 0.008), TIL PD-L1 expression (P < 0.001), oestrogen (ER) negativity (P < 0.001), progesterone (PR) negativity (P < 0.001), human epidermal growth factor receptor 2 (HER2) positivity (P = 0.002) and triple negativity (P = 0.001). TIL PD-L1 expression was associated with triple-negative DCIS (P = 0.028). TIL density was associated with molecular subtypes (P < 0.001). High CD4+ T cell density was associated with high nuclear grade (P = 0.001), microinvasion (P = 0.037), ER negativity (P < 0.001), PR negativity (P = 0.001), HER2 positivity (P = 0.004), triple negativity (P = 0.023) and PD-L1 expression in TILs (P < 0.011). High CD4/CD8 ratio was associated with PD-L1 expression in DCIS (P = 0.035) and TILs (P < 0.001). DCIS with higher TIL density disclosed worse DFS (P = 0.012) and was affirmed with multivariate analysis [95% confidence interval (CI) = 1.109-2.554, hazard ratio (HR) = 1.683, P = 0.014]. Poorer DFS for ipsilateral invasive recurrence was found for DCIS with higher CD4+ T cell density (P = 0.006) or CD4/CD8 ratio (P = 0.02), confirmed by multivariate analysis for the former (95% CI = 1.369-10.196, HR = 3.736, P = 0.01) and latter (95% CI = 1.311-7.935, HR = 3.225, P = 0.011). CONCLUSION: DCIS with higher TIL density was associated with poorer prognostic parameters and predicted recurrence, while both CD4+ T cell density and CD4/CD8 ratio were associated with both recurrence and ipsilateral invasive recurrence.

Outbreak of Measles in a Residential Home for the Intellectually Disabled in Singapore in 2019.

A measles outbreak involving 19 adults in a home for the intellectually disabled occurred in Singapore in 2019. Further investigation, including a serological survey, was conducted. Mass vaccination and infection control measures were implemented, terminating further secondary transmission. Seropositivity among residents aged 40 to 49 years (90.7%; 95% confidence interval = 78.4%, 96.3%) was lower than among the Singapore adult population (P < .001). This sheltered population, like others previously reported in the literature, had lower measles immunity than the general community, possibly because of limited social interaction. Targeted catch-up vaccination for similarly vulnerable populations should be considered.

Genomic characterisation of breast fibroepithelial lesions in an international cohort.

Fibroepithelial lesions (FELs) are a heterogeneous group of tumours comprising fibroadenomas (FAs) and phyllodes tumours (PTs). Here we used a 16-gene panel that was previously discovered to be implicated in pathogenesis and progression, to characterise a large international cohort of FELs via targeted sequencing. The study comprised 303 (38%) FAs and 493 (62%) PTs which were contributed by the International Fibroepithelial Consortium. There were 659 (83%) Asian and 109 (14%) non-Asian FELs, while the ethnicity of the rest was unknown. Genetic aberrations were significantly associated with increasing grade of PTs, and were detected more in PTs than FAs for MED12, TERT promoter, RARA, FLNA, SETD2, TP53, RB1, EGFR, and IGF1R. Most borderline and malignant PTs possessed ≥ 2 mutations, while there were more cases of FAs with ≤ 1 mutation compared to PTs. FELs with MED12 mutations had significantly higher rates of TERT promoter, RARA, SETD2, EGFR, ERBB4, MAP3K1, and IGF1R aberrations. However, FELs with wild-type MED12 were more likely to express TP53 and PIK3CA mutations. There were no significant differences observed between the mutational profiles of recurrent FAs, FAs with a history of subsequent ipsilateral recurrence or contralateral occurrence, and FAs without a history of subsequent events. We identified recurrent mutations which were more frequent in PTs than FAs, with borderline and malignant PTs harbouring cancer driver gene and multiple mutations. This study affirms the role of a set of genes in FELs, including its potential utility in classification based on mutational profiles. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Invasive breast cancer: Current perspectives and emerging views.

Invasive breast cancer constitutes a heterogeneous group of tumors. They comprise various histological types that differ in clinical presentation, imaging features, histopathological characteristics, biomarker profiles, prognostic and predictive parameters. The current classification of invasive breast cancer is based primarily on histopathological features. Invasive carcinoma of no special type accounts for the majority, with some rare entities also being described. With recent research and advances, there are emerging concepts, including new genetic insights of invasive breast cancer and the role of the stromal microenvironment. With greater understanding of the pathogenesis of invasive breast cancer, changes based on the correlation of histologic and genetic findings have been incorporated in the latest World Health Organization classification of breast tumors. Medullary carcinomas are subsumed as invasive carcinoma of no special type with basal-like and medullary features, regarded as part of the spectrum of tumor infiltrating lymphocyte-rich breast cancers. Tall cell carcinoma with reversed polarity is proposed as a distinct entity in recognition of unique IDH2 mutations. This article reviews conventional prognostic parameters, new histological entities, and updates on breast cancer classification, with inclusion of some genetic insights into breast cancer and the role of tumor infiltrating lymphocytes.

Genomic profile of breast sarcomas: a comparison with malignant phyllodes tumours.

PURPOSE: We aimed to investigate the genomic profile of breast sarcomas (BS) and compare with that of malignant phyllodes tumours (MPT). METHODS: DNA was extracted from formalin-fixed, paraffin-embedded (FFPE) specimens from 17 cases of BS diagnosed at Singapore General Hospital from January 1991 to December 2014. Targeted deep sequencing and copy number variation (CNV) analysis on 16 genes, which included recurrently mutated genes in phyllodes tumours and genes associated with breast cancer, were performed on these samples. Genetic alterations (GA) observed were summarised and analysed. RESULTS: Nine cases met the quality control requirements for both targeted deep sequencing and CNV analysis. Three (33.33%) were angiosarcomas and 6 (66.67%) were non-angiosarcomas. In the non-angiosarcoma group, 83.33% (n = 5) of the patients had GA in the TERT gene. The other commonly mutated genes in this group of tumours were MED12 (n = 4, 66.67%), BCOR (n = 4, 66.67%), KMT2D (n = 3, 50%), FLNA (n = 3, 50%) and NF1 (n = 3, 50%). In contrast, none of the angiosarcomas had mutations or copy number alterations in TERT, MED12, BCOR, FLNA or NF1. Eighty percent of patients with GA in TERT (n = 5) had concurrent mutations in MED12. Sixty percent (n = 3) of these cases also demonstrated GA in NF1, PIK3CA or EGFR which are known cancer driver genes. CONCLUSIONS: The non-angiosarcoma group of BS was found to share similar GA as those described for MPT, which may suggest a common origin and support their consideration as a similar group of tumours with regard to management and prognostication.

Behaviour and characteristics of low-grade ductal carcinoma in situ of the breast: literature review and single-centre retrospective series.

AIMS: Ductal carcinoma in situ (DCIS) of the breast is a heterogeneous disease that has risen to prominence and more recently controversy, with the advent of screening mammography. Debate concerning the true biological potential of low nuclear grade DCIS continues to challenge therapeutic considerations. In this study, we carried out a comprehensive literature review of the behaviour, outcomes and current management trials of low-grade DCIS, as well as a retrospective study of a large single institutional series of low-grade DCIS diagnosed at our hospital. METHODS AND RESULTS: The study cohort comprised 195 cases of low-grade DCIS diagnosed at the Singapore General Hospital from 1994 to 2010. Clinicopathological parameters and follow-up data were retrieved and compared between screen-detected and symptomatic low-grade DCIS. Immunohistochemistry was performed for ER, PR and HER2. Among 195 cases, 123 (63.1%) were screen-detected, while 72 (36.9%) were symptomatic. Screen-detected cases had frequent calcifications (P < 0.001) and were smaller (P = 0.018) than symptomatic cases. All cases were ER-positive and rate of PR expression was high. No HER2 overexpression was observed. Mean and median follow-up periods were 107.8 and 109.6 months, respectively. Six patients recurred ipsilaterally, and one patient developed direct distant metastasis. One breast cancer-related death was recorded. Positive surgical margins (P = 0.023) were significantly associated with a higher risk of ipsilateral recurrences, as well as poorer disease-free survivals (P = 0.010). CONCLUSION: Our data indicate that low-grade DCIS may be followed by invasive recurrences and even metastatic disease, requiring more study before being regarded as innocuous and indolent.

Prognostic significance of epithelial-mesenchymal transition proteins Twist and Foxc2 in phyllodes tumours of the breast.

Epithelial-mesenchymal transition (EMT), an important process during embryonic development, is reportedly exploited during tumour progression. Deregulation of EMT-related molecules has been shown in many malignancies, including breast carcinoma. We aim to investigate the clinical relevance and prognostic significance of EMT proteins, Twist and Foxc2, in breast phyllodes tumours (PTs). The study cohort comprised 271 PTs diagnosed from 2003 to 2010. Of these, 188 (69.4 %) were benign, 60 (22.1 %) borderline, and 23 (8.5 %) malignant. Immunohistochemistry for Twist and Foxc2 was performed on tissue microarray sections. Percentage of tumour cells stained was evaluated and correlated with clinicopathological parameters and clinical outcome. Twist and Foxc2 stromal nuclear expression was associated with tumour grade (P = 0.038 and 0.012). Foxc2 stromal nuclear expression was positively correlated with epithelial expression (P < 0.001), tumour relapse, and metastasis (P = 0.037). Furthermore, stromal nuclear immunoreactivity of Twist and Foxc2 was interrelated (P < 0.001). Tumours expressing Foxc2 and those co-expressing both Twist and Foxc2 revealed a shorter time to recurrence (P < 0.001 and 0.001) and death (P = 0.044 and 0.015). Twist and Foxc2 stromal expression in PTs was significantly correlated with tumour grade and worse histological features. In addition, expression of Foxc2 and co-expression of Twist and Foxc2 in the stroma of PTs contributed to poorer prognosis. Clinical relevance of EMT-related molecules may be worthy of further investigation in PTs.

Role of epithelial-mesenchymal transition markers in triple-negative breast cancer.

Triple-negative breast cancers (TNBCs) are a heterogeneous group of breast tumours that are often associated with adverse pathological characteristics, poorer clinical outcomes and lack of targeted therapeutic options. Epithelial-mesenchymal transition, which plays a crucial role in tumour development and progression, is characterised by a transition from epithelial to mesenchymal phenotype and loss of proteins involved in maintaining cell junctions. We aimed to correlate protein expression of E-cadherin, Snail2 and transforming growth factor beta (TGF-ß) with clinicopathological parameters and survivals of a series of patients with TNBC. The study cohort comprised 767 TNBCs diagnosed at the Department of Pathology, Singapore General Hospital from 1994 to 2012. Immunohistochemistry was performed on sections cut from tissue microarrays using the polymeric method. Staining intensity and percentage of positive tumour cells were evaluated and correlated with clinicopathological findings and clinical outcomes. Loss of E-cadherin expression, Snail2 positivity, cytoplasmic and nuclear expression of TGF-ß were observed in 265 (35.2 %), 241 (32.0 %), 272 (36.2 %) and 262 (34.8 %) tumours, respectively. Histological grade significantly correlated with Snail2 positivity (P < 0.001) and loss of membranous E-cadherin expression (P = 0.003). Nuclear expression of TGF-ß was inversely correlated with histological grade (P = 0.010). Median follow-up was 73 months, with a maximum of 236 months. Despite a graphical curve for earlier recurrence in patients with tumours harbouring a combinational phenotype of loss of membranous E-cadherin and positive Snail2 expression, there was no statistical significance. Similarly for women with tumours expressing cytoplasmic TGF-ß, graphical representation showed poorer metastasis-free survival but without statistical significance. Loss of membranous E-cadherin and positive Snail2 expression are significantly associated with high-grade TNBCs. More work is needed to improve understanding of the role of TGF-ß in TNBC.

Characteristics and behaviour of screen-detected ductal carcinoma in situ of the breast: comparison with symptomatic patients.

Breast cancer is the most common malignancy in Singapore women. Ductal carcinoma in situ (DCIS) is the putative, non-obligate precursor of the majority of invasive breast cancers. The efficacy of the Singapore breast-screening pilot project in detecting early stage breast cancer led to the launch of a national breast-screening programme, BreastScreen Singapore (BSS), in January 2002. In this study, we compared clinicopathological and immunohistochemical characteristics, as well as clinical outcomes, between screen-detected and symptomatic DCIS. The study cohort comprised 1202 cases of DCIS diagnosed at Singapore General Hospital from 1994 to 2010. Comparison of clinicopathological parameters, immunohistochemical results of ER, PR, HER2, CK14, EGFR, and 34ßE12, and clinical outcomes was carried out between the 2 groups. Amongst 1202 cases, 610 (50.7%) were screen-detected and 592 (49.3%) were symptomatic DCIS. Screen-detected cases were smaller in size (P < 0.001), of lower nuclear grade (P = 0.004), and more frequently expressed ER (P < 0.001). Luminal A phenotype was more frequently observed in screen-detected DCIS, while triple-negative and HER2 phenotypes were more common in symptomatic DCIS (P < 0.001). The basal-like phenotype was also more frequent in symptomatic DCIS (P = 0.041). Mean and median follow-up was 99.7 and 97.8 months, respectively, with a maximum follow-up of 246.0 months. More symptomatic patients developed invasive recurrences compared to screen-detected patients (P = 0.001). A trend for better disease-free survival was observed in screen-detected patients (P = 0.076). Patients who were screen-detected experienced better overall survival than those with symptomatic DCIS (P = 0.007). Our data indicate a more favourable outcome of screen-detected DCIS patients confirming the role of BSS in early identification of this curable disease.

Novel genetic aberrations in breast phyllodes tumours: comparison between prognostically distinct groups.

Phyllodes tumours of the breast are uncommon fibroepithelial neoplasms which pose management challenges due to difficulties in accurate prediction of clinical behaviour, as histological assessment has its limitations. Molecular studies have improved the understanding of these rare tumours but such findings are scant. We aimed to investigate genetic aberrations in phyllodes tumours stratified according to clinical behaviour, to identify potential genes contributing to disease progression. Twenty phyllodes tumours were separated into prognostically distinct categories depending on whether they had recurred/metastasized within the follow-up period. DNA extracted from FFPE materials was subjected to Affymetrix OncoScan™ FFPE Express molecular inversion probe microarray platform for analysis of copy number changes and mutational status. Results were cross validated with Sanger sequencing, FISH and immunohistochemistry. A higher number of chromosomal aberrations were observed in cases which recurred/metastasized, with median events of 19 compared to 3.5 in cases which did not recur/metastasize. High-level amplification and homozygous deletions were detected exclusively in the former group. Regions of high-level amplification included MDM4 (1q32.1), RAF1 (3p25), EGFR (7p12) and PDZD2 (5p13.3). EGFR amplification was confirmed on FISH and accompanied by intense EGFR immunostaining. Regions of homozygous deletion included CDKN2A (9p21) and MACROD2 (20p12.1). Homozygous deletion of 9p21 which involved CDKN2A was accompanied by loss of protein expression. No mutations were identified in all samples. These findings provide insights into identifying target genes and pathways exploited by phyllodes tumours, which would aid future development of individualised therapy.

Breast ductal Carcinoma in situ associated with microinvasion induces immunological response and predicts ipsilateral invasive recurrence.

Although microinvasion (Mi) is often thought to be an interim stage between ductal carcinoma in situ (DCIS) and established invasive ductal carcinoma, survival outcomes and biological behaviour of DCIS-Mi are still poorly understood. This study investigated the potential influence of Mi on disease-free survival (DFS) and assessed its correlations with clinicopathological parameters, prognosis, molecular, and immune markers. CD4, CD8, forkhead box P3 (FOXP3), CD68, CD163, programmed cell death protein 1 (PD-1), and its ligand (PD-L1) expression in pure DCIS and DCIS-Mi, from a cohort of 198 patients, were determined by immunohistochemistry. DFS, clinicopathological parameters, immune markers, and biomarker expression were correlated with presence of Mi. Twelve out of 198 DCIS cases were associated with Mi. DCIS-Mi was significantly linked with ipsilateral invasive recurrence (p = 0.032). Kaplan-Meier analysis revealed that DCIS-Mi had worse DFS for ipsilateral invasive recurrence (p = 0.011) and this was affirmed by multivariate Cox regression analysis (95% CI 1.181-9.010, HR = 3.262, p = 0.023). DCIS-Mi was associated with higher densities of immune infiltrates positive for CD4 (p = 0.037), FOXP3 (p = 0.037), CD163 (p = 0.01), and PD-L1 (p = 0.015). This study demonstrated that DCIS-Mi was correlated with high densities of immune infiltrates and predicted ipsilateral invasive recurrence.