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The most commonly utilized class of chemotherapeutic agents administered as a first-line therapy are antimitotic drugs; however, their clinical success is often impeded by chemoresistance and disease relapse. Hence, a better understanding of the cellular pathways underlying escape from cell death is critical. Mitotic slippage describes the cellular process where cells exit antimitotic drug-enforced mitotic arrest and “slip” into interphase without proper chromosome segregation and cytokinesis. The current report explores the cell fate consequence following mitotic slippage and assesses a major outcome following treatment with many chemotherapies, therapy-induced senescence. It was found that cells postslippage entered senescence and could impart the senescence-associated secretory phenotype (SASP). SASP factor production elicited paracrine protumorigenic effects, such as migration, invasion, and vascularization. Both senescence and SASP factor development were found to be dependent on autophagy. Autophagy induction during mitotic slippage involved the autophagy activator AMPK and endoplasmic reticulum stress response protein PERK. Pharmacologic inhibition of autophagy or silencing of autophagy-related ATG5 led to a bypass of G1 arrest senescence, reduced SASP-associated paracrine tumorigenic effects, and increased DNA damage after S-phase entry with a concomitant increase in apoptosis. Consistent with this, the autophagy inhibitor chloroquine and microtubule-stabilizing drug paclitaxel synergistically inhibited tumor growth in mice. Sensitivity to this combinatorial treatment was dependent on p53 status, an important factor to consider before treatment.Implications: Clinical regimens targeting senescence and SASP could provide a potential effective combinatorial strategy with antimitotic drugs. Mol Cancer Res; 16(11); 1625–40. ©2018 AACR.

S1. Post-slippage cells arrest at G1 as tetraploid multinucleated cells. S2. Correlation of multinucleation and senescence post-slippage in response to various anti-mitotic drugs. S3. In vivo association of senescence and anti-mitotic drug treatment. S4. Post-slippage cells increase expression of factors associated with senescence and SASP. S5. SASP factors from post-slippage cells do not affect proliferation of neighbouring cells. S6. Autophagy mediates senescence. S7. Autophagy does not modulate cell fate during prolonged mitotic arrest. S8. Autophagy-dependent IL-1β and IL-8 expression mediate cell invasiveness in a paracrine manner. S9. Silencing of p53 increases post-slippage cell death. S10. p53 status determines synergistic effect of microtubule poisons and autophagy inhibition. Table S1. List of differentially regulated proteins after 48 h Noc treatment detected by SILAC mass spectrometry. Table S2. List of antibodies. Table S3. List of chemicals. Table S4. List of primers. Table S5. Quantitative H scoring method

A breast cancer polygenic risk score (PRS) comprising 313 common variants reliably predicts disease risk. We examined possible relationships between genetic variation, regulation, and expression to clarify the molecular alterations associated with these variants. Genome-wide methylomic variation was quantified (MethylationEPIC) in Asian breast cancer patients (1152 buffy coats from peripheral whole blood). DNA methylation (DNAm) quantitative trait loci (mQTL) mapping was performed for 235 of the 313 variants with minor allele frequencies > 5%. Stability of identified mQTLs (p

Male breast cancer (MBC) is rare, representing1% of all breast cancers. Treatment recommendations have been extrapolated from trial data of female breast cancer patients. This study aims to report our institutional experience of MBC across a 20 year period, analyse the survival outcome and prognosis of this group against female breast cancer patients treated at the same centre.Clinical, histopathological, treatment and survival data of male and female breast cancer patients treated between Jan 1999 and July 2019 at Singapore General Hospital and National Cancer Centre Singapore were identified and analysed.Fifty-seven male patients were identified. The median age at diagnosis was 63 years. Majority had invasive ductal carcinoma (86%) and presented at an early disease stage: 70.2% presented as Tis/T1/T2 and 49.1% had no axillary nodal involvement. 84.2% had a simple mastectomy with either a sentinel lymph node biopsy or axillary clearance. The median follow up was 5.69 years for males and 5.83 years for females. The median survival was 11.86 years for males and 16.3 years for females. At 5 years, overall survival (OS) was 69.9% (52.3-82.1%) and disease free survival (DFS) was 62.9% (44.9-76.5%) for males compared with OS 83.8% (83.21-84.39%) and DFS 74.5% (73.91-75.09%) for females.MBC remains understudied. Our institutional data indicates that good long term survival in South-East Asian patients can be achieved with treatment protocols that are similar to female breast cancer. More prospective studies are required.

Ductal carcinoma in situ (DCIS) of the breast is a heterogeneous disease which is increasingly diagnosed through improved screening measures. Multiple prognostic scores have been devised to predict the risk of local recurrence (LR), and the optimal adjuvant management for DCIS is still debated. Hence, the aim of this analysis is to investigate the factors contributing to the prognosis of DCIS, in particular the role of its hormonal status. From 2005 to 2016, a total of 1221 female patients diagnosed with DCIS at the National Cancer Centre Singapore and Singapore General Hospital were studied. The mean age of diagnosis was 54 years of age (sd = 11.0), with estrogen receptor (ER)-positive DCIS tumors presenting earlier (mean age 54 vs 57 years of age; P < .001). DCIS with negative hormonal status (HS) correlates significantly with a larger size (mean 23.5mm vs 13.0 mm, P < .001) and higher grade of tumor (P < .001). Patients with positive HS were more likely to undergo breast conservation surgery over a mastectomy, in contrast to patients with negative HS (P < .001). Patients with negative HS had a poorer prognosis, with a shorter time of overall survival time (HR = 26.3, P = .020). In conclusion, our study shows that the hormonal status, age of diagnosis, and positive margins are important prognostic factors for DCIS, at least in our Asian population.

IntroductionStatins, HMG-CoA reductase inhibitors, are commonly used cholesterol-lowering medications which are also increasingly recognized to have anti-cancer properties for various cancers, including breast cancer. Most clinical evidence supports a protective effect of statin on reducing breast cancer recurrence, particularly in hormone-receptor positive breast cancers.This study seeks to study the impact of statin use on breast cancer recurrence in an Asian population.MethodsThis is a retrospective study of patients diagnosed with breast cancer at the National Cancer Centre and Singapore General Hospital from 2005-2015. Statin use was defined as use after surgery. Associations between statin use, breast cancer recurrence and overall survival were estimated using Cox proportional hazards regression with adjustment for age, TNM stage, grade, ER/HER2 status, and co-morbidities. Associations between statin-use and disease-specific survival were estimated using competing risks regression.ResultsA total of 7858 females with breast cancer were studied, 1353(17.2%) were statin users, 6505(82.8%) were non-statin users, with a median follow-up of 8.67 years. Distribution of cancer stage, histology, molecular subtypes and grades were similar in both groups. Estrogen receptor(ER) positive (HR 0.57,95%CI 0.43-0.76,pConclusionThis is the first known retrospective study on the effect of statin use and breast cancer recurrence in an Asian population. Similar to previous international studies, statin use is associated with a risk reduction in breast cancer recurrence. This is especially beneficial in patients who have ER+ and HER2- invasive breast cancer. Statin use is also associated with a reduced risk of breast cancer recurrence in all subtypes of breast cancer in the long term (>6 years post diagnosis).

Malignant phyllodes tumors (PT) are rare aggressive fibroepithelial neoplasms with high metastatic potential and lack effective therapy. We established a patient-derived xenograft (PDX) and cell line model (designated MPT-S1) of malignant PT which demonstrated clinical response to pazopanib. Whole exome sequencing identified somatic mutations in TP53, RB1, MED12, and KMT2D. Immunohistochemistry and genomic profiles of the tumor, PDX and cell line were concordant. In keeping with clinical observation, pazopanib reduced cell viability in a dose-dependent manner and evoked apoptosis, and led to significant abrogation of in vivo tumor growth. Whole transcriptomic analysis revealed that pazopanib decreased expression of genes involved in oncogenic and apoptosis signaling. We also observed decreased expression of ENPP1, with known roles in cancer invasion and metastasis, as well as STING pathway upregulation. Accordingly, pazopanib induced micronuclei formation, and evoked phospho-TBK1 and PD-L1 expression. In an additional cohort of malignant PT (n = 14), six (42.9%) showed comparable or higher levels of ENPP1 relative to MPT-S1, highlighting its potential role as a therapeutic target. In conclusion, we established MPT-S1, a new PDX and cell line model, and provided evidence for the clinical efficacy of pazopanib in malignant PT.

Studies that report equivalent oncologic outcomes of sentinel lymph node biopsy (SLNB) alone versus axillary lymph node dissection (ALND) for T1-2N1mi breast cancers are heavily weighted with patients who received breast-conserving surgery (BCS). The impact of omitting ALND in N1mi patients treated with mastectomy is not well studied. It is also unknown if these patients would benefit from post-mastectomy radiotherapy (PMRT). This study reports the outcomes of patients with T1-2N1mi breast cancer treated by mastectomy without axillary therapy.Patients who had T1-2N1mi breast cancer and underwent mastectomy from January 1998 to December 2018 were identified from our multi-institutional prospective database. Axillary recurrence rate (ARR), disease-free survival (DFS), and overall survival (OS) are reported.260 patients with pT1-2N1mi breast cancer who had mastectomy were identified. They had either SLNB (35.4%) or ALND (64.6%). Majority of these patients received adjuvant systemic therapy (93.8%). 77 (29.6%) patients received radiotherapy, 31 after SLNB and 46 after ALND. At median follow-up of 61 months, ARR was 1.1% (n = 1) in the SLNB only group, vs. 0.6% (n = 1) in the ALND group (p = 0.752). DFS and OS were not significantly different between patients with SLNB alone versus ALND (p = 0.40 and p = 0.27, respectively). Among 92 patients who had SLNB only, no DFS or OS difference was observed with the use of PMRT.In T1-2N1mi patients with mastectomy and SLNB, axillary recurrences were rare. No statistically significant differences were noted between patients with SLNB, ALND, or PMRT. Our findings suggest that these patients may be safely treated without axillary therapy.

Simple Summary Breast cancer screening by mammography suffers from high rates of false positivity, resulting in unnecessary investigative imaging and biopsies. There is an unmet need for biomarkers that can distinguish between malignant and benign breast lesions. We performed miRNA profiling on 638 patients with abnormal mammograms and 100 healthy controls. A six-miRNA panel was identified and validated in an independent cohort that had an AUC of 0.881 when differentiating between cases versus those with benign lesions or healthy individuals with normal mammograms. In addition, biomarker panel scores increased with tumor size, stage and number of lymph nodes involved. This study demonstrates that circulating miRNAs can potentially be used in conjunction with mammography to differentiate between patients with malignant and benign breast lesions. Abstract Mammography is extensively used for breast cancer screening but has high false-positive rates. Here, prospectively collected blood samples were used to identify circulating microRNA (miRNA) biomarkers to discriminate between malignant and benign breast lesions among women with abnormal mammograms. The Discovery cohort comprised 72 patients with breast cancer and 197 patients with benign breast lesions, while the Validation cohort had 73 and 196 cancer and benign cases, respectively. Absolute expression levels of 324 miRNAs were determined using RT-qPCR. miRNA biomarker panels were identified by: (1) determining differential expression between malignant and benign breast lesions, (2) focusing on top differentially expressed miRNAs, and (3) building panels from an unbiased search among all expressed miRNAs. Two-fold cross-validation incorporating a feature selection algorithm and logistic regression was performed. A six-miRNA biomarker panel identified by the third strategy, had an area under the curve (AUC) of 0.785 and 0.774 in the Discovery and Validation cohorts, respectively, and an AUC of 0.881 when differentiating between cases versus those with benign lesions or healthy individuals with normal mammograms. Biomarker panel scores increased with tumor size, stage and number of lymph nodes involved. Our work demonstrates that circulating miRNA signatures can potentially be used with mammography to differentiate between patients with malignant and benign breast lesions.

Background Mutations in certain genes are known to increase breast cancer risk. We study the relevance of rare protein-truncating variants (PTVs) that may result in loss-of-function in breast cancer susceptibility genes on tumor characteristics and survival in 8852 breast cancer patients of Asian descent. Methods Gene panel sequencing was performed for 34 known or suspected breast cancer predisposition genes, of which nine genes (ATM, BRCA1, BRCA2, CHEK2, PALB2, BARD1, RAD51C, RAD51D, and TP53) were associated with breast cancer risk. Associations between PTV carriership in one or more genes and tumor characteristics were examined using multinomial logistic regression. Ten-year overall survival was estimated using Cox regression models in 6477 breast cancer patients after excluding older patients (≥75years) and stage 0 and IV disease. Results PTV9genes carriership (n = 690) was significantly associated (p < 0.001) with more aggressive tumor characteristics including high grade (poorly vs well-differentiated, odds ratio [95% confidence interval] 3.48 [2.35–5.17], moderately vs well-differentiated 2.33 [1.56–3.49]), as well as luminal B [HER−] and triple-negative subtypes (vs luminal A 2.15 [1.58–2.92] and 2.85 [2.17–3.73], respectively), adjusted for age at diagnosis, study, and ethnicity. Associations with grade and luminal B [HER2−] subtype remained significant after excluding BRCA1/2 carriers. PTV25genes carriership (n = 289, excluding carriers of the nine genes associated with breast cancer) was not associated with tumor characteristics. However, PTV25genes carriership, but not PTV9genes carriership, was suggested to be associated with worse 10-year overall survival (hazard ratio [CI] 1.63 [1.16–2.28]). Conclusions PTV9genes carriership is associated with more aggressive tumors. Variants in other genes might be associated with the survival of breast cancer patients. The finding that PTV carriership is not just associated with higher breast cancer risk, but also more severe and fatal forms of the disease, suggests that genetic testing has the potential to provide additional health information and help healthy individuals make screening decisions.

Description, Fatty acid oxidation is a metabolic gateway that regulates cellular plasticity and supports metastasis in breast cancer., Cell state transitions control the functional behavior of cancer cells. Epithelial-to-mesenchymal transition (EMT) confers cancer stem cell-like properties, enhanced tumorigenicity and drug resistance to tumor cells, while mesenchymal-epithelial transition (MET) reverses these phenotypes. Using high-throughput chemical library screens, retinoids are found to be potent promoters of MET that inhibit tumorigenicity in basal-like breast cancer. Cell state transitions are defined by reprogramming of lipid metabolism. Retinoids bind cognate nuclear receptors, which target lipid metabolism genes, thereby redirecting fatty acids for β-oxidation in the mesenchymal cell state towards lipid storage in the epithelial cell state. Disruptions of key metabolic enzymes mediating this flux inhibit MET. Conversely, perturbations to fatty acid oxidation (FAO) rechannel fatty acid flux and promote a more epithelial cell phenotype, blocking EMT-driven breast cancer metastasis in animal models. FAO impinges on the epigenetic control of EMT through acetyl-CoA-dependent regulation of histone acetylation on EMT genes, thus determining cell states.

Background: The hypothesis that breast cancer (BC) susceptibility variants are linked to chemotherapy-induced toxicity has been previously explored. Here, we investigated the association between a validated 313-marker-based BC polygenic risk score (PRS) and chemotherapy-induced neutropenia without fever and febrile neutropenia (FNc) in Asian BC patients. Methods: This observational case-control study of Asian BC patients treated with chemotherapy included 161 FNc patients, 219 neutropenia patients, and 936 patients who did not develop neutropenia. A continuous PRS was calculated by summing weighted risk alleles associated with overall, estrogen receptor- (ER-) positive, and ER-negative BC risk. PRS distributions neutropenia or FNc cases were compared to controls who did not develop neutropenia using two-sample t-tests. Odds ratios (OR) and corresponding 95% confidence intervals were estimated for the associations between PRS (quartiles and per standard deviation (SD) increase) and neutropenia-related outcomes compared to controls. Results: PRS distributions were not significantly different in any of the comparisons. Higher PRSoverall quartiles were negatively correlated with neutropenia or FNc. However, the associations were not statistically significant (PRS per SD increase OR neutropenia: 0.91 [0.79–1.06]; FNc: 0.87 [0.73–1.03]). No dose-dependent trend was observed for the ER-positive weighted PRS (PRSER-pos) and ER-negative weighted PRS (PRSER-neg). Conclusion: BC PRS was not strongly associated with chemotherapy-induced neutropenia or FNc.

A breast cancer polygenic risk score (PRS) comprising 313 common variants reliably predicts disease risk. We examined possible relationships between genetic variation, regulation, and expression to clarify the molecular alterations associated with these variants.Genome-wide methylomic variation was quantified (MethylationEPIC) in Asian breast cancer patients (1152 buffy coats from peripheral whole blood). DNA methylation (DNAm) quantitative trait loci (mQTL) mapping was performed for 235 of the 313 variants with minor allele frequencies 5%. Stability of identified mQTLs (p 5e-8) across lifetime was examined using a public mQTL database. Identified mQTLs were also mapped to expression quantitative trait loci (eQTLs) in the Genotype-Tissue Expression Project and the eQTLGen Consortium.Breast cancer PRS was not associated with DNAm. A higher proportion of significant cis-mQTLs were observed. Of 822 significant cis-mQTLs (179 unique variants) identified in our dataset, 141 (59 unique variants) were significant (p 5e-8) in a public mQTL database. Eighty-six percent (121/141) of the matched mQTLs were consistent at multiple time points (birth, childhood, adolescence, pregnancy, middle age, post-diagnosis, or treatment). Ninety-three variants associated with DNAm were also cis-eQTLs (35 variants not genome-wide significant). Multiple loci in the breast cancer PRS are associated with DNAm, contributing to the polygenic nature of the disease. These mQTLs are mostly stable over time.Consistent results from DNAm and expression data may reveal new candidate genes not previously associated with breast cancer.

The ensuing COVID-19 pandemic poses unprecedented and daunting challenges to the routine delivery of oncological and supportive care to patients with breast cancer. Considerations include the infective risk of patients who are inherently immunosuppressed from their malignancy and therapies, long-term oncological outcomes from the treatment decisions undertaken during this extraordinary period, and diverted healthcare resources to support a coordinated whole-of-society outbreak response. In this review, we chronicle the repercussions of the COVID-19 outbreak on breast cancer management in Singapore and describe our approach to triaging and prioritising care of breast tumours. We further propose adaptations to established clinical processes and practices across the different specialties involved in breast oncology, with references to the relevant evidence base or expert consensus guidelines. These recommendations have been developed within the unique context of Singapore’s public healthcare sector. They can serve as a resource to guide breast cancer management for future contingencies in this city-state, while certain elements therein may be extrapolatable to other medical systems during this global public health emergency.

Breast cancer survival has improved with significant progress in treatment and disease management. However, compliance with treatment varies. Treatment guidelines for older patients are unclear. We aim to identify predictors of noncompliance with recommended therapy in a large breast cancer population and assess the impact of noncompliance on survival. Our study included 19,241 non-metastatic female breast cancer patients, of whom 3,158 (16%) died within 10 years post-diagnosis (median survival = 5.8 years). We studied the association between treatment noncompliance and factors with logistic regression, and the impact of treatment noncompliance on survival with a flexible parametric survival model framework. The highest proportion of noncompliance was observed for chemotherapy (18%). Predictors of noncompliance with chemotherapy, radiotherapy and endocrine therapy included age, tumor size, nodal involvement and subtype (except radiotherapy). Factors associated with not receiving surgery included age and subtype. Treatment noncompliance was associated with worse overall survival for surgery (HR: 2.26 [1.80–2.83]), chemotherapy (1.25 [1.11–1.41]), radiotherapy (2.28 [1.94–2.69]) and endocrine therapy (1.70 [1.41–2.04]). Worse survival was similarly observed in older patients for whom guidelines generally do not apply. Our results highlight the importance of following appropriate treatment as recommended by current guidelines. Older patients may benefit from similar recommendations.

Purpose: Atypical ductal hyperplasia (ADH) is a high risk lesion with an increased risk of developing breast cancer. This study aims to identify factors predictive of malignant upgrade for ADH diagnosed on core needle biopsy (CNB) and to develop a nomogram to facilitate evidence-based decision making.Methods: Retrospective analysis of women with CNB diagnosed ADH at the National Cancer Centre Singapore between 2010 and 2015 was performed. Cox proportional hazards regression was used to identify independent clinical, radiological and histological factors associated with malignant upgrade. A nomogram was constructed and multivariable logistic regression coefficients were used to estimate the predicted probability of upgrade for each factor combination. Combinations with the lowest predicted probabilities (≤5%) were identified as low risk. Model sensitivity, specificity, positive and negative predictive values were assessed.Results: From 2010-2015, 238,122 women underwent screening under the national breast cancer screening programme. 29,564 women were recalled and 5742 CNBs were performed, of which 2686 were performed at NCCS. 88 patients (90 lesions) were diagnosed with ADH. 26 lesions were upgraded to a breast malignancy on excision biopsy. On univariate analysis, presence of a mass on either ultrasound (p= 0.018) or mammogram (p=0.026), presence of mammographic microcalcifications (p=0.047), diffuse microcalcification distribution (p=0.034), mammographic parenchymal density (p=0.008), presence of microcalcifications on biopsy (p=0.037) and three or more separate foci of ADH found on biopsy (p=0.024) were associated with malignant upgrade. Mammographic parenchymal density (Hazard ratio= 0.04, 95% CI 0.005-0.35, p=0.014), presence of a mass on ultrasound (Hazard ratio= 10.50, 95% CI 9.21-25.2, p=0.010) and number of foci of ADH (Hazard ratio = 1.877, 95% CI 1.831-1.920, p=0.002) remained significant on multivariate analysis and were included in the normogram which demonstrated good discrimination with C-statistic of 0.81 [95% CI, 0.74 to 0.88].Conclusion: Our model provides good discrimination of breast cancer risk prediction in patients with ADH on CNB. A subset of women at low risk (

Nipple-sparing mastectomy (NSM) allows for excellent postmastectomy reconstruction aesthetics and is used for both therapeutic and risk-reducing purposes. Reservations regarding the potential for locoregional recurrence and concerns about nipple–areolar complex (NAC) necrosis remain amongst many surgeons. We review the surgical and oncological outcomes after NSM in our institution. All NSM cases at the National Cancer Centre Singapore and Singapore General Hospital between 2005 and 2015 were reviewed. Tumour characteristics, reconstruction methods, surgical and oncological outcomes are described. A total of 139 NSMs were performed for 130 patients. The median age was 46 years (range 21–66). The use of NSM increased from 2% of all breast reconstructions in 2005 to 37% in 2015. The majority (n = 119; 86%) were for cancer treatment and 20 (14%) for risk-reducing purposes. Among those performed for cancer, patients mainly had early stage breast cancer (n = 106, 89%). Autologous reconstruction (n = 111, 80%) was most common. Early complications requiring surgical intervention occurred in 24 (17%) NSMs, including 9 partial/complete flap loss and 2 complete NAC loss. Smoking, previous breast radiation and periareolar incision were all not associated with a higher re-intervention rate (p = 0.93, 0.41 and 0.91, respectively). Median follow-up was 43 months (range 5–145). Five patients (4%) developed local recurrence, including 2 NAC recurrences. The 2- and 5-year overall survival rate is 97 and 90%, respectively. NSM is an oncologically safe procedure in selected patients with acceptable low complication rates.

Background Women with unilateral breast cancer have an increased risk of developing bilateral breast cancer (BBC). Patients with metachronous BBC (mBBC) usually have an earlier age of onset, and their prognoses have been shown to be either similar or poorer than those with synchronous BBC (sBBC). Given the differing presentation and characteristics of breast cancers in the Asian population and the West, this study aims to characterize Asian patients with BBC. Methods All patients who had oncological breast surgery between 2001 and 2010 at the Singapore General Hospital and National Cancer Centre Singapore were reviewed. Patients with BBC were identified and studied. Results A total of 5520 Singaporean women had oncological breast surgery, 155 women (2.8%) had BBC. Of those with BBC, 47.1% (n = 73) were synchronous and 52.9% (n = 82) metachronous (mean interval of 39.4 months), and there was no difference in median age in both groups (54 years of age). Patients with sBBC were more likely to have a positive family history and had asymptomatic contralateral tumours. Although patients with sBBCs were more likely to have ER/PR positive and Her2 negative tumours, they had a lower 5-year overall survival than those with mBBC (P = 0.022). Conclusion Our study shows that Asian women with BBC have different characteristics to their Western counterparts. In particular, women with sBBC tended to have a lower 5-year overall survival compared to those with mBBC, despite having seemingly biologically favourable tumours, which suggest that there may be more underlying their tumour biology and genetics.

Aim The optimal treatment of breast cancer for extremely elderly patients (aged ≥ 80 years) is debatable. With an aging population, management of this group of patients will be increasingly common. This study aims to compare the survival outcomes of extremely elderly patients against younger ones, following different treatment modalities within each stage. The differences in treatment patterns across different stages have also been examined. Methods Female Singapore Citizens and Permanent Residents diagnosed with breast cancer from 2003 to 2014 were identified from the Singapore Cancer Registry. Patients were divided into 2 age groups, below 80, and 80 and above years old, and categorized into 3 main treatment groups, namely surgery, non-surgical treatment, and no treatment. Analysis was made on their survival outcomes. Results 19,314 patients were diagnosed with breast cancer during the 12-year study period. 1482 patients were excluded due to unknown stage. 673 patients were aged 80 years and above, while 17,159 patients were aged below 80. Elderly patients presented with later stages of disease, and were less likely to have surgery. In Stage I and II, the difference in 5-year breast cancer specific outcome following surgery, was small between the 2 age groups. Among the elderly group, surgery resulted in improved survival. Those who did not have surgery performed better with endocrine therapy than with no treatment. Conclusions Extremely elderly patients, especially those with Stages I and II breast cancer do not fare worse than younger patients, and should be offered surgery if they are fit.

Although mammography is the gold standard for breast cancer screening, the high rates of false-positive mammograms remain a concern. Thus, there is an unmet clinical need for a non-invasive and reliable test to differentiate between malignant and benign breast lesions in order to avoid subjecting patients with abnormal mammograms to unnecessary follow-up diagnostic procedures. Serum samples from 116 malignant breast lesions and 64 benign breast lesions were comprehensively profiled for 2,083 microRNAs (miRNAs) using next-generation sequencing. Of the 180 samples profiled, three outliers were removed based on the principal component analysis (PCA), and the remaining samples were divided into training (n = 125) and test (n = 52) sets at a 70:30 ratio for further analysis. In the training set, significantly differentially expressed miRNAs (adjusted p &lt, 0.01) were identified after correcting for multiple testing using a false discovery rate. Subsequently, a predictive classification model using an eight-miRNA signature and a Bayesian logistic regression algorithm was developed. Based on the receiver operating characteristic (ROC) curve analysis in the test set, the model could achieve an area under the curve (AUC) of 0.9542. Together, this study demonstrates the potential use of circulating miRNAs as an adjunct test to stratify breast lesions in patients with abnormal screening mammograms.

BackgroundKnown collectively as breast fibroepithelial lesions (FELs), the common fibroadenomas (FAs) and the rarer phyllodes tumors (PTs) are a heterogenous group of biphasic neoplasms. Owing to limited tissue availability, inter-observer variability, overlapping histological features and heterogeneity of these lesions, diagnosing them accurately on core biopsies is challenging. As the choice management option depends on the histological diagnosis; a novel 16-gene panel assay was developed to improve the accuracy of preoperative diagnosis on core biopsy specimens.MethodsUsing this 16-gene panel, targeted amplicon-based sequencing was performed on 275 formalin-fixed, paraffin-embedded (FFPE) breast FEL specimens, archived at the Singapore General Hospital, from 2008 to 2012.ResultsIn total, 167 FAs, 24 benign, 14 borderline and 6 malignant PTs, were profiled. Compared to FAs, PTs had significantly higher mutation rates in theTERTpromoter (p RARA(p FLNA,RB1andTP53(p = 0.002, 0.020 and 0.018, respectively). In addition to a higher mutational count (p TERTpromoter (p p = 0.001, A multivariate logistic regression model was built using these as variables and a predictive scoring system was developed. It classifies a FEL at low or high risk (score p = 0.945) and is significant in predicting PTs (p ConclusionThis novel study demonstrates the ability to extract DNA of sufficient quality and quantity for targeted sequencing from FFPE breast core biopsy specimens, along with their successful characterization and profiling using our customized 16-gene panel. Prospective work includes validating the utility of this promising 16-gene panel assay as an adjunctive diagnostic tool in clinical practice.

e12540 Background: An inflammatory state in various cancer populations may correlate with mortality. Neutrophil-lymphocyte ratio is a surrogate marker of an inflammatory state. A recent meta-analysis showed the predictive value of neutrophil to lymphocyte ratio in breast cancers, but series are generally small. We aim to study the associations of Neutrophil-Lymphocyte Ratio (NLR) with outcomes in stage I–III breast cancer in patients who received neo-adjuvant chemotherapy (NAC) or upfront surgery. The endpoints are overall survival (OS) and breast cancer-specific survival (BCSS). In the NAC group, association with pathological complete response (PCR) rate was also studied. Methods: Data of patients with stage I–III breast cancer treated from 2011–2017 were extracted from a prospectively maintained registry and merged with full blood count (FBC) results from a clinical management software. FBC were performed within one-month pre-chemo for NAC patients and one-month pre-surgery for upfront surgery patients. PCR is defined as stage ypT0/isN0M0. OS is defined as death from any cancer from diagnosis date, censored at last follow-up. BCSS is defined as death from breast cancer from diagnosis date, censored at last follow up or death from any cause. The NLR values with the maximal Youden’s indexes calculated for each outcome were used as cut-off, logistic regression was used to determine PCR association and cox regression and log rank for OS and BCSS. Results: A total of 2,479 eligible patients were analysed. Overall, treatment compliance was high (87.6% of ER+ patients received endocrine treatment, and 94.1% of HER2+ NAC patients had targeted therapy). In the NAC group (n = 357), 23% achieved PCR. NLR did not show any statistically significant association with PCR. In unadjusted analysis, high NLR was associated with worse BCSS (log-rank p = 0.003 figure 1). In multivariable analysis (MVA), only triple negative and HER-enriched cancers were significantly associated with PCR. In NAC patients, NLR was associated with OS (cut-off 2.63; OR 1.6, p = 0.077) and BCSS (cut-off 3.58; OR 2.2, p = 0.003) in MVA. In patients treated with up-front surgery (n = 2122), unadjusted analysis showed high NLR was associated with worse BCSS (OR 1.55, p = 0.05; figure 2). In MVA, NLR (cut-off 2.13, OR 1.57, p = 0.005), triple negative histology, stage and age were significant predictors of OS. BCSS was not significantly associated with NLR (OR 1.38 95%CI 0.90-2.12 p = 0.145). Conclusions: Using a large cohort of patients, a high NLR was found to be associated with worse outcomes in NAC and upfront surgery breast cancer patients.

Background Socioeconomic status (SES) is likely to affect survival in breast cancer patients. Housing value is a reasonable surrogate for SES in Singapore where most residents own their own homes, which could be public (subsidised) or private housing. We evaluated effects of housing value and enhanced medical subsidies on patients’ presentation, treatment choices, compliance and survival in a setting of good access to healthcare. Methods A retrospective analysis of breast cancer patients treated in a tertiary hospital cluster from 2000 to 2016 was performed. Individual-level Housing value Index (HI) was derived from each patient's address and then grouped into 3 tiers: HI(high)(minimal subsidy), HI(med)(medium subsidy) and HI(low)(high subsidy). Cox regression was performed to evaluate the associations between overall survival (OS) and cancer-specific survival (CSS) with HI and various factors. Findings We studied a multiracial cohort of 15,532 Stage 0–IV breast cancer patients. Median age was 53.7 years and median follow-up was 7.7 years. Patients with lower HI presented with more advanced disease and had lower treatment compliance. On multivariable analysis, compared to HI(high) patients, HI(med) patients had decreased OS (HR=1.14, 95% CI 1.05–1.23) and CSS (HR=1.15, 95% CI 1.03–1.27), and HI(low) patients demonstrated reduced OS (HR=1.16, 95% CI 1.01–1.33). Ten-year non-cancer mortality was higher in lower HI-strata. Enhanced medical subsidy approximately halved treatment noncompliance rates but its receipt was not an independent prognostic factor for survival. Interpretation Despite good healthcare access, lower-HI patients have poorer survival from both cancer and non-cancer causes, possibly due to delayed health-seeking and poorer treatment compliance. Enhanced subsidies may mitigate socioeconomic disadvantages. Funding None.

Post-mastectomy breast reconstruction is an integral component of breast cancer treatment. It is often perceived that women in Asian countries have a lower rate of post-mastectomy reconstruction than Western populations. This study describes trends in timing and types of breast reconstruction performed in the largest healthcare provider in Singapore, over a period of 12 years. It also reports on the oncological outcomes and surgical safety. A retrospective review of all patients who underwent post-mastectomy reconstruction from January 2001 to December 2012 at the National Cancer Centre Singapore and Singapore General Hospital was performed. Six hundred and twenty post-mastectomy reconstructions were performed in 579 patients. The proportion of reconstructions increased from 4% in 2001 to 18% in 2012. Younger patients (

Women with unilateral breast cancer have an increased risk of developing bilateral breast cancer (BBC). Patients with metachronous BBC (mBBC) usually have an earlier age of onset, and their prognoses have been shown to be either similar or poorer than those with synchronous BBC (sBBC). Given the differing presentation and characteristics of breast cancers in the Asian population and the West, this study aims to characterize Asian patients with BBC.All patients who had oncological breast surgery between 2001 and 2010 at the Singapore General Hospital and National Cancer Centre Singapore were reviewed. Patients with BBC were identified and studied.A total of 5520 Singaporean women had oncological breast surgery, 155 women (2.8%) had BBC. Of those with BBC, 47.1% (n = 73) were synchronous and 52.9% (n = 82) metachronous (mean interval of 39.4 months), and there was no difference in median age in both groups (54 years of age). Patients with sBBC were more likely to have a positive family history and had asymptomatic contralateral tumours. Although patients with sBBCs were more likely to have ER/PR positive and Her2 negative tumours, they had a lower 5-year overall survival than those with mBBC (P = 0.022).Our study shows that Asian women with BBC have different characteristics to their Western counterparts. In particular, women with sBBC tended to have a lower 5-year overall survival compared to those with mBBC, despite having seemingly biologically favourable tumours, which suggest that there may be more underlying their tumour biology and genetics.

The most commonly utilized class of chemotherapeutic agents administered as a first-line therapy are antimitotic drugs; however, their clinical success is often impeded by chemoresistance and disease relapse. Hence, a better understanding of the cellular pathways underlying escape from cell death is critical. Mitotic slippage describes the cellular process where cells exit antimitotic drug-enforced mitotic arrest and “slip” into interphase without proper chromosome segregation and cytokinesis. The current report explores the cell fate consequence following mitotic slippage and assesses a major outcome following treatment with many chemotherapies, therapy-induced senescence. It was found that cells postslippage entered senescence and could impart the senescence-associated secretory phenotype (SASP). SASP factor production elicited paracrine protumorigenic effects, such as migration, invasion, and vascularization. Both senescence and SASP factor development were found to be dependent on autophagy. Autophagy induction during mitotic slippage involved the autophagy activator AMPK and endoplasmic reticulum stress response protein PERK. Pharmacologic inhibition of autophagy or silencing of autophagy-related ATG5 led to a bypass of G1 arrest senescence, reduced SASP-associated paracrine tumorigenic effects, and increased DNA damage after S-phase entry with a concomitant increase in apoptosis. Consistent with this, the autophagy inhibitor chloroquine and microtubule-stabilizing drug paclitaxel synergistically inhibited tumor growth in mice. Sensitivity to this combinatorial treatment was dependent on p53 status, an important factor to consider before treatment. Implications: Clinical regimens targeting senescence and SASP could provide a potential effective combinatorial strategy with antimitotic drugs. Mol Cancer Res; 16(11); 1625–40. ©2018 AACR.

Background: Sentinel lymph node biopsy (SLNB) has been widely used in early breast cancer patients for the detection of axillary nodal metastasis. We were the first to describe 2 novel sentinel nodal stations (SNS) in relation to the intercostobrachial nerve (ICB) and the medial pectoral neurovascular bundle (MP) at which sentinel lymph nodes (SLN) were consistently identified, even only with the use of blue dye. In a pilot study involving 176 cases, we have shown that the ICB and MP SNS represent sequential echelons of SLN draining the breast. It was observed that the status of the MP SNS can be used in predicting the likelihood of additional non sentinel lymph node metastasis in early breast cancer. Thus, we aim to compare this against the Singapore General Hospital (SGH) nomogram, the existing standard predictive model in the local population. The SGH nomogram was developed from predictors in the Memorial Sloan-Kettering Cancer Centre (MSKCC) nomogram. It uses only 3 pathological parameters: lymphovascular invasion, number of positive and negative SLN. This has been shown to be at least equal if not better than the MSKCC nomogram as a predictive model in the Singapore population. Methods : All patients who underwent oncologic breast surgery and SLNB (using the SNS identification technique) at the Department of Surgical Oncology, National Cancer Centre Singapore from February 2012 to December 2013 inclusive were reviewed. Patients who fulfilled the following selection criteria were included in the study: [1] invasive ductal or lobular carcinoma, [2] SLN identified in both ICB and MP SNS,[3] axillary clearance done with total lymph nodes ≥ 10, based on a positive SLNB. The performance of the MP SNS status and SGH nomogram in predicting the likelihood of additional non sentinel lymph node metastasis was compared with the calculation of the area under the receiver-operating characteristic curve (AUC). Results: A total of 49 patients were identified. Majority of the patients had early breast cancers: 94% had tumour size ≤5cm and 71% had N1 disease. The median number of total SLN, ICB and MP nodes identified were 3 (range 2-14), 2 (range 1-7) and 1 (range 1-12) respectively. The median number of positive and negative SLN were both 1 (range 1-5 and 0-9 respectively). The positive predictive value of MP SNS status for additional non sentinel lymph node metastasis was 76.5% (95% CI: 50.1-93.2). The strong association was proven by an odds ratio of 7.15 (95% CI 1.86-27.50, p-value: 0.002). The negative predictive value of MP SNS for eventual N stage was 93.8% (95% CI: 79.2-99.2). In most of the cases, the nodal stage remained at N1 in the presence of negative MP node. The model with MP SNS status yielded an AUC of 0.706 (95% CI: 0.579-0.832) which was higher than that of the SGH nomogram, 0.658 (95% CI: 0.503-0.813). Conclusions: The novel MP SNS proved to be a single parameter which predicts the likelihood of additional non sentinel lymph nodes metastasis better than the SGH nomogram. More importantly, from the clinical point of view, the MP SNS status can be made available intra-operatively and hence guide the decision for further axillary dissection. Citation Format: Sue Zann Lim, Puay Hoon Tan, Gay Hui Ho, Preetha Madhukumar, Yirong Sim, Shaun Shi Yan Tan, Cindy Lim, Veronique Kiak Mien Tan, Kong Wee Ong. Predicting the likelihood of additional non sentinel lymph node metastasis in early breast cancer: Novel sentinel nodal station status versus Singapore General Hospital nomogram [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-08-52.

Medullary Thyroid Carcinoma (MTC) is the most common cause of death in MEN patients. It is curative by prophylactic total thyroidectomy, but controversies remain as to the optimal timing for prophylactic thyroidectomy. The current recommendation is for prophylactic total thyroidectomy before age 5, but a recent study suggested that in the ethnic Chinese, even "high risk" mutations did not result in early malignant change, and it was suggested that prophylactic thyroidectomy may be performed at a later age. We report a case of an ethnic Chinese girl with MEN2A codon 634 (C634R) mutation, whose operative specimen at prophylactic thyroidectomy at 4 years 8 months showed MTC. We advocate that management of MEN2A patients should be codon-directed, regardless of ethnicity.

Triple-negative breast cancer (TNBC), as immunohistochemically defined by its estrogen receptor (ER)-negative, progesterone receptor (PR)-negative and human epidermal growth factor receptor-2 (HER2)-negative status, is an important subtype due to its biologically aggressive behavior and limited treatment options available. TNBC is associated with an overall poorer prognosis, with higher risk of disease recurrence/progression and shorter duration of treatment response, i.e., treatment resistance. Treatment resistance may be largely attributed to cancer stem cells (CSCs), which are intrinsically treatment resistant and continually self-renew, proliferate, and differentiate into different phenotypes. Activation of the cell biologic program, epithelial-mesenchymal transition (EMT), has been demonstrated to promote the dedifferentiation of heterogeneous subpopulations of cancer cells towards CSC phenotypes. We hypothesized that induction of the mesenchymal-epithelial transition (MET) program might disrupt CSC function, drive differentiation, and render greater susceptibility to conventional chemotherapy. In this study, we utilized high-throughput chemical-genetic screens to uncover a potent class of MET mediators. With the use of in vitro and in vivo models of TNBC, we showed that changing the malignant cell state to a differentiated phenotype by inducing MET reduced mammosphere formation, increased chemosensitivity, and decreased the tumor burden in NSG mice. Delving into the mechanisms of tumor differentiation via ChIP-seq, RNA-seq, and Gene Ontology analysis revealed differences in metabolic status between cell states, which might be exploited in the treatment of TNBC. We also assessed combinations of MET mediators, in order to increase the potency and durability of differentiation. Hence, this study assessed the role of differentiation in the treatment of TNBC and the efficacy of various MET mediators, singly and in combination, in inducing differentiation. Citation Format: Ser Yue Loo, Liping Toh, Elina Pathak, Wilson Tan, Siming Ma, Ju Yuan, Giridharan Periyasamy, Federico Torta, Jack Chan, Tira Tan, Yi Rong Sim, Veronique Tan, Benita Tan, Preetha Madhukumar, Wei Sean Yong, Kong Wee Ong, Chow Yin Wong, Markus R. Wenk, Roger Foo, Yoon-Sim Yap, Elaine Lim, Wai Leong Tam. Inducing cell state transitions in triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the AACR Special Conference: Advances in Breast Cancer Research; 2017 Oct 7-10; Hollywood, CA. Philadelphia (PA): AACR; Mol Cancer Res 2018;16(8_Suppl):Abstract nr B22.

Polyphosphoinositol lipids convey spatial information partly by their interactions with cellular proteins within defined domains. However, these interactions are prevented when the lipids' head groups are masked by the recruitment of cytosolic effector proteins, whereas these effectors must also have sufficient mobility to maximize functional interactions. To investigate quantitatively how these conflicting functional needs are optimized, we used different fluorescence recovery after photobleaching techniques to investigate inositol lipid-effector protein kinetics in terms of the real-time dissociation from, and diffusion within, the plasma membrane. We find that the protein-lipid complexes retain a relatively rapid ( approximately 0.1-1 microm(2)/s) diffusion coefficient in the membrane, likely dominated by protein-protein interactions, but the limited time scale (seconds) of these complexes, dictated principally by lipid-protein interactions, limits their range of action to a few microns. Moreover, our data reveal that GAP1(IP4BP), a protein that binds PtdIns(4,5)P(2) and PtdIns(3,4,5)P(3) in vitro with similar affinity, is able to "read" PtdIns(3,4,5)P(3) signals in terms of an elongated residence time at the membrane.

The endoplasmic reticulum (ER) is a dynamic organelle thought to consist of a single interconnected network of membranes. Using fluorescence recovery after photobleaching (FRAP) of HEK-293 cells dually transfected with soluble fluorescent proteins targeted to the ER (GFP) and mitochondria (DsRed), we have confirmed this continuity, which contrasts that of the mitochondria, which behave as a population of discrete organelles. The degree of ER integrity (interconnected versus fragmented) has been suggested to be regulated in some cells by inositol 1,3,4,5-tetrakisphosphate (Ins(1,3,4,5)P-4). In HEK-293 and freshly isolated murine lacrimal acinar cells, we manipulated ER structure by disrupting cellular Ca2+ homeostasis with the Ca2+ ionophore ionomycin, and by permeabilisation of the plasma membrane, protocols known to cause ER fragmentation. However, we were subsequently unable to detect by FRAP any significant effect of Ins(1,3,4,5)P-4 on ER integrity.(c) 2005 Elsevier Ltd. All rights reserved.

Background Contralateral prophylactic mastectomy (CPM) removes the non-diseased breast in women who have unilateral breast cancer. This reduces the incidence of contralateral breast cancer, and potentially improves survival in high risk patients. Such surgical risk-reduction strategy is increasingly being adopted in the United States, despite a decreasing incidence of contralateral breast cancer. The use of CPM in an Asian population is yet unknown. We present the first Asian report on CPM rates and trends in Singapore, the country with the highest incidence of breast cancer in Asia. Methods A retrospective review of all patients who had breast cancer surgery from 2001 to 2010 at the largest healthcare system in Singapore was performed. Patient demographics and tumour characteristics were analysed with regards to type of surgery performed. Factors associated with CPM were identified. Results From 2001 to 2010, a total of 5130 patients underwent oncological breast surgery. A decreasing trend of mastectomies (82.7%–70.8%), an upward trend of breast conserving surgery (BCS) (17.3%–29.2%) and an increasing trend in CPM (0.46%–1.25%) is observed. Patients who opted for CPM are likely to be younger (48.4 ± 9.4 years), married (60%), parous (56.7%), with no family history of breast/ovarian cancer (66.7%), and diagnosed at an earlier stage. The rate of synchronous occult breast malignancy was found to be 10% ( n = 30), and these were in patients who were of a low cancer-risk profile. Conclusions This retrospective study reflects an increasing incidence of breast cancer in Singapore, with a decrease in mastectomies, and an increase in BCS and CPM rates, similar to Western data. Similar to Western populations, the Asian woman who opts for CPM is likely to be young and have an earlier stage of breast cancer. In contrast, the Asian woman is likely to have no family history of breast or ovarian cancers. Commonly cited reasons for increased CPM rates such as the increased availability of genetic counselling and pre-operative MRI evaluation, along with wide use of reconstruction, do not feature as dominant factors in our population, suggesting that the Asian patients may have different considerations when electing for CPM.