Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
LanguageLanguage
-
SubjectSubject
-
Item TypeItem Type
-
DisciplineDiscipline
-
YearFrom:-To:
-
More FiltersMore FiltersIs Peer Reviewed
Done
Filters
Reset
58
result(s) for
"Tan, Benita Kiat-Tee"
Sort by:
Impact of deviation from guideline recommended treatment on breast cancer survival in Asia
2020
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.
Journal Article
Exome sequencing identifies breast cancer susceptibility genes and defines the contribution of coding variants to breast cancer risk
by
Hartman, Mikael
,
Pita, Guillermo
,
Collin-Deschesnes, Annie Claude
in
45/23
,
692/308/174
,
692/308/2056
2023
Linkage and candidate gene studies have identified several breast cancer susceptibility genes, but the overall contribution of coding variation to breast cancer is unclear. To evaluate the role of rare coding variants more comprehensively, we performed a meta-analysis across three large whole-exome sequencing datasets, containing 26,368 female cases and 217,673 female controls. Burden tests were performed for protein-truncating and rare missense variants in 15,616 and 18,601 genes, respectively. Associations between protein-truncating variants and breast cancer were identified for the following six genes at exome-wide significance (
P
<
2.5 × 10
−6
): the five known susceptibility genes
ATM
,
BRCA1
,
BRCA2
,
CHEK2
and
PALB2
, together with
MAP3K1
. Associations were also observed for
LZTR1
,
ATRIP
and
BARD1
with
P
< 1 × 10
−4
. Associations between predicted deleterious rare missense or protein-truncating variants and breast cancer were additionally identified for
CDKN2A
at exome-wide significance. The overall contribution of coding variants in genes beyond the previously known genes is estimated to be small.
Meta-analysis of three large whole-exome sequencing datasets highlights protein-truncating and rare missense variants associated with breast cancer susceptibility.
Journal Article
Alterations to DNA methylation patterns induced by chemotherapy treatment are associated with negative impacts on the olfactory pathway
by
Hartman, Mikael
,
Iau, Philip Tsau-Choong
,
Khng, Alexis Jiaying
in
Algorithms
,
Analysis
,
B cells
2023
Background
Exposure to cytotoxic chemotherapy treatment may alter DNA methylation (DNAm) in breast cancer patients.
Methods
We performed DNAm analysis in 125 breast cancer patients with blood drawn before and after chemotherapy, using the Illumina MethylationEPIC array. DNAm changes of 588,798 individual CpGs (including 41,207 promoter regions) were evaluated using linear regression models adjusted for monocyte proportion. Gene set enrichment analyses (GSEA) were conducted to identify key Gene Ontology (GO) biological processes or Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with chemotherapy. Results were validated in a separate cohort of breast cancer patients who were treated (
n
= 1273) and not treated (
n
= 872) by chemotherapy (1808 blood, 337 saliva).
Results
A total of 141 differentially methylated CpGs and 11 promoters were significantly associated with chemotherapy after multiple testing corrections in both the paired sample and single time point analyses. GSEA of promoter regions (pre-ranked by test statistics) identified six suppressed biological processes (
p
< 4.67e−8) related to sensory perception and detection of chemical stimuli, including smell perception (GO:0007606, GO:0007608, GO:0009593, GO:0050906, GO:0050907, and GO:0050911). The same six biological processes were significantly suppressed in the validation dataset (
p
< 9.02e−14). The KEGG pathway olfactory transduction (hsa04740) was also found to be significantly suppressed (
p
paired-samples
= 1.72e−9, p
single-timepoint-blood
= 2.03e−15 and
p
single-timepoint-saliva
= 7.52e−56).
Conclusion
The enrichment of imprinted genes within biological processes and pathways suggests a biological mechanism by which chemotherapy could affect the perception of smell.
Journal Article
Genetic differences between benign phyllodes tumors and fibroadenomas revealed through targeted next generation sequencing
2021
Breast fibroepithelial lesions are biphasic tumors which comprise the common benign fibroadenomas (FAs) and the rarer phyllodes tumors (PTs). This study analyzed 262 (42%) conventional FAs, 45 (7%) cellular FAs, and 321 (51%) benign PTs contributed by the International Fibroepithelial Consortium, using a previously curated 16 gene panel. Benign PTs were found to possess a higher number of mutations, and higher rates of cancer driver gene alterations than both groups of FAs, in particular MED12, TERT promoter, RARA, FLNA, SETD2, RB1, and EGFR. Cases with MED12 mutations were also more likely to have TERT promoter, RARA, SETD2, and EGFR. There were no significant differences detected between conventional FAs and cellular FAs, except for PIK3CA and MAP3K1. TERT promoter alterations were most optimal in discriminating between FAs and benign PTs. Our study affirms the role of sequencing and key mutations that may assist in refining diagnoses of these lesions.
Journal Article
Whole‐exome sequencing of breast cancer, malignant peripheral nerve sheath tumor and neurofibroma from a patient with neurofibromatosis type 1
by
Madhukumar, Preetha
,
Rajasegaran, Vikneswari
,
Ngeow, Joanne
in
Adult
,
Amino acids
,
Brain tumors
2015
Neurofibromatosis type 1 (NF1) is a genetic disorder characterized by the development of multiple neurofibromas, cafe‐au‐lait spots, and Lisch nodules. Individuals with NF1 are at increased risk of developing various tumors, such as malignant peripheral nerve sheath tumor (MPNST), pheochromocytoma, leukemia, glioma, rhabdomyosarcoma, and breast cancer. Here, we describe the exome sequencing of breast cancer, MPNST, and neurofibroma from a patient with NF1. We identified a germline mutation in the NF1 gene which resulted in conversion of leucine to proline at amino acid position 847. In addition, we showed independent somatic NF1 mutations in all the three tumors (frameshift insertion in breast cancer (p.A985fs), missense mutation in MPNST (p.G23R), and inframe deletion in dermal neurofibroma (p.L1876del‐Inf)), indicating that a second hit in NF1 resulting in the loss of function could be important for tumor formation. Each tumor had a distinct genomic profile with mutually exclusive mutations in different genes. Copy number analysis revealed multiple copy number alterations in the breast cancer and the MPNST, but not the benign neurofibroma. Germline loss of chromosome 6q22.33, which harbors two potential tumor suppressor genes, PTPRK and LAMA2, was also identified; this may increase tumor predisposition further. In the background of NF1 syndrome, although second‐hit NF1 mutation is critical in tumorigenesis, different additional mutations are required to drive the formation of different tumors. Exome sequencing of breast cancer, malignant peripheral nerve sheath tumor (MPNST), and neurofibroma from an Neurofibromatosis type 1 (NF1) patient reveal independent second‐hit somatic NF1 mutations in all three tumors. The additional genomic aberrations required to drive the formation of different types of tumors are, however, distinct. The novel finding of germline loss of PTPRK and LAMA2 may also increase tumor predisposition.
Journal Article
Overlap of high-risk individuals predicted by family history, and genetic and non-genetic breast cancer risk prediction models: implications for risk stratification
by
Hartman, Mikael
,
Ngeow, Joanne
,
Dunning, Alison M.
in
Asian People
,
Biomedicine
,
BRCA1 protein
2022
Background
Family history, and genetic and non-genetic risk factors can stratify women according to their individual risk of developing breast cancer. The extent of overlap between these risk predictors is not clear.
Methods
In this case-only analysis involving 7600 Asian breast cancer patients diagnosed between age 30 and 75 years, we examined identification of high-risk patients based on positive family history, the Gail model 5-year absolute risk [5yAR] above 1.3%, breast cancer predisposition genes (protein-truncating variants [PTV] in
ATM
,
BRCA1
,
BRCA2
,
CHEK2
,
PALB2
,
BARD1
,
RAD51C
,
RAD51D
, or
TP53
), and polygenic risk score (PRS) 5yAR above 1.3%.
Results
Correlation between 5yAR (at age of diagnosis) predicted by PRS and the Gail model was low (
r
=0.27). Fifty-three percent of breast cancer patients (
n
=4041) were considered high risk by one or more classification criteria. Positive family history, PTV carriership, PRS, or the Gail model identified 1247 (16%), 385 (5%), 2774 (36%), and 1592 (21%) patients who were considered at high risk, respectively. In a subset of 3227 women aged below 50 years, the four models studied identified 470 (15%), 213 (7%), 769 (24%), and 325 (10%) unique patients who were considered at high risk, respectively. For younger women, PRS and PTVs together identified 745 (59% of 1276) high-risk individuals who were not identified by the Gail model or family history.
Conclusions
Family history and genetic and non-genetic risk stratification tools have the potential to complement one another to identify women at high risk.
Journal Article
An in-depth exploration of the post-test informational needs of BRCA1 and BRCA2 pathogenic variant carriers in Asia
by
Courtney, Eliza
,
Tan, Benita Kiat-Tee
,
Shaw, Tarryn
in
Analysis
,
Biomedical and Life Sciences
,
Biomedicine
2020
Introduction
Identification of one’s status as a
BRCA1/2
pathogenic variant carrier often marks the start of navigating challenging decisions related to cancer risk management and result disclosure. Carriers report unmet informational needs, but studies have yet to explore the specific aspects of and how best to fulfill these needs. This study aims to explore the informational needs of
BRCA1/2
pathogenic variant carriers in Asia to inform for the design of educational materials to support risk management decision-making.
Methods
Semi-structured in-depth interviews were conducted with two male and 22 female English-speaking
BRCA1/2
pathogenic variant carriers, aged 29–66 years, identified through the Cancer Genetics Service at the National Cancer Centre Singapore. A grounded theory approach with thematic analysis was undertaken to extract dominant themes.
Results
Four themes were identified: (i) proactive online information seeking behaviors (ii) personalized informational needs; (iii) challenges in sharing the results; and (iv) lack of genetic awareness.
Discussion
Participants highlight challenges with sharing their result arising from significant post-result informational needs, which have manifested into proactive online information-seeking behaviors. They desire for an online source of information, where content is personalized, reliable and local. Participants foresee the potential of an online resource to raise genetic awareness. This suggests the use of a culturally tailored online-based genetics resource, to promote result disclosure, empower risk-management decisions and raise genetic literacy rates.
Journal Article
Germline breast cancer susceptibility genes, tumor characteristics, and survival
by
Hartman, Mikael
,
Ngeow, Joanne
,
Dunning, Alison M.
in
Analysis
,
Associations, institutions, etc
,
Bioinformatics
2021
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
PTV
9genes
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. PTV
25genes
carriership (
n
= 289, excluding carriers of the nine genes associated with breast cancer) was not associated with tumor characteristics. However, PTV
25genes
carriership, but not PTV
9genes
carriership, was suggested to be associated with worse 10-year overall survival (hazard ratio [
CI
] 1.63 [1.16–2.28]).
Conclusions
PTV
9genes
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.
Journal Article
TWEAK/Fn14 signalling driven super-enhancer reprogramming promotes pro-metastatic metabolic rewiring in triple-negative breast cancer
2024
Triple Negative Breast Cancer (TNBC) is the most aggressive breast cancer subtype suffering from limited targeted treatment options. Following recent reports correlating Fibroblast growth factor-inducible 14 (Fn14) receptor overexpression in Estrogen Receptor (ER)-negative breast cancers with metastatic events, we show that Fn14 is specifically overexpressed in TNBC patients and associated with poor survival. We demonstrate that constitutive Fn14 signalling rewires the transcriptomic and epigenomic landscape of TNBC, leading to enhanced tumour growth and metastasis. We further illustrate that such mechanisms activate TNBC-specific super enhancers (SE) to drive the transcriptional activation of cancer dependency genes via chromatin looping. In particular, we uncover the SE-driven upregulation of Nicotinamide phosphoribosyltransferase (NAMPT), which promotes NAD+ and ATP metabolic reprogramming critical for filopodia formation and metastasis. Collectively, our study details the complex mechanistic link between TWEAK/Fn14 signalling and TNBC metastasis, which reveals several vulnerabilities which could be pursued for the targeted treatment of TNBC patients.
Triple Negative Breast Cancer (TNBC) is the most aggressive breast cancer subtype. Here, the authors show that TWEAK/Fn14 signalling promotes TNBC metastasis through extensive transcriptomic and epigenetic remodelling, highlighting it as a promising therapeutic target.
Journal Article
Profiling Microbial Communities in Idiopathic Granulomatous Mastitis
2023
Idiopathic granulomatous mastitis (IGM) is a rare and benign inflammatory breast disease with ambiguous aetiology. Contrastingly, lactational mastitis (LM) is commonly diagnosed in breastfeeding women. To investigate IGM aetiology, we profiled the microbial flora of pus and skin in patients with IGM and LM. A total of 26 patients with IGM and 6 patients with LM were included in the study. The 16S rRNA sequencing libraries were constructed from 16S rRNA gene amplified from total DNA extracted from pus and skin swabs in patients with IGM and LM controls. Constructed libraries were multiplexed and paired-end sequenced on HiSeq4000. Metagenomic analysis was conducted using modified microbiome abundance analysis suite customised R-resource for paired pus and skin samples. Microbiome multivariable association analyses were performed using linear models. A total of 21 IGM and 3 LM paired pus and skin samples underwent metagenomic analysis. Bray−Curtis ecological dissimilarity distance showed dissimilarity across four sample types (IGM pus, IGM skin, LM pus, and LM skin; PERMANOVA, p < 0.001). No characteristic dominant genus was observed across the IGM samples. The IGM pus samples were more diverse than corresponding IGM skin samples (Shannon and Simpson index; Wilcoxon paired signed-rank tests, p = 0.022 and p = 0.07). Corynebacterium kroppenstedtii, reportedly associated with IGM in the literature, was higher in IGM pus samples than paired skin samples (Wilcoxon, p = 0.022). Three other species and nineteen genera were statistically significant in paired IGM pus–skin comparison after antibiotic treatment adjustment and multiple comparisons correction. Microbial profiles are unique between patients with IGM and LM. Inter-patient variability and polymicrobial IGM pus samples cannot implicate specific genus or species as an infectious cause for IGM.
Journal Article