Displaying publications 1 - 20 of 147 in total

  1. Zulkhernain NS, Teo SH, Patel V, Tan PJ
    Curr Cancer Drug Targets, 2014;14(8):764-73.
    PMID: 25348017 DOI: 10.2174/1568009614666141028121347
    Targeted therapy, the treatment of cancer based on an underlying genetic alteration, is rapidly gaining favor as the preferred therapeutic approach. To date, although natural products represent a rich resource of bio-diverse drug candidates, only a few have been identified to be effective as targeted cancer therapies largely due to the incompatibilities to current high-throughput screening methods. In this article, we review the utility of a zebrafish developmental screen for bioactive natural product-based compounds that target signaling pathways that are intimately shared with those in humans. Any bioactive compound perturbing signaling pathways identified from phenotypic developmental defects in zebrafish embryos provide an opportunity for developing targeted therapies for human cancers. This model provides a promising tool in the search for targeted cancer therapeutics from natural products.
  2. Zeng C, Guo X, Long J, Kuchenbaecker KB, Droit A, Michailidou K, et al.
    Breast Cancer Res., 2016 06 21;18(1):64.
    PMID: 27459855 DOI: 10.1186/s13058-016-0718-0
    BACKGROUND: Multiple recent genome-wide association studies (GWAS) have identified a single nucleotide polymorphism (SNP), rs10771399, at 12p11 that is associated with breast cancer risk.

    METHOD: We performed a fine-scale mapping study of a 700 kb region including 441 genotyped and more than 1300 imputed genetic variants in 48,155 cases and 43,612 controls of European descent, 6269 cases and 6624 controls of East Asian descent and 1116 cases and 932 controls of African descent in the Breast Cancer Association Consortium (BCAC; http://bcac.ccge.medschl.cam.ac.uk/ ), and in 15,252 BRCA1 mutation carriers in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Stepwise regression analyses were performed to identify independent association signals. Data from the Encyclopedia of DNA Elements project (ENCODE) and the Cancer Genome Atlas (TCGA) were used for functional annotation.

    RESULTS: Analysis of data from European descendants found evidence for four independent association signals at 12p11, represented by rs7297051 (odds ratio (OR) = 1.09, 95 % confidence interval (CI) = 1.06-1.12; P = 3 × 10(-9)), rs805510 (OR = 1.08, 95 % CI = 1.04-1.12, P = 2 × 10(-5)), and rs1871152 (OR = 1.04, 95 % CI = 1.02-1.06; P = 2 × 10(-4)) identified in the general populations, and rs113824616 (P = 7 × 10(-5)) identified in the meta-analysis of BCAC ER-negative cases and BRCA1 mutation carriers. SNPs rs7297051, rs805510 and rs113824616 were also associated with breast cancer risk at P 

  3. Yoon SY, Thong MK, Taib NA, Yip CH, Teo SH
    Fam. Cancer, 2011 Jun;10(2):199-205.
    PMID: 21318382 DOI: 10.1007/s10689-011-9420-7
    Genetic counseling (GC) and genetic testing are vital risk management strategies in hereditary breast and ovarian cancer (HBOC) syndromes. Hitherto, cancer genetic testing amongst Asians has been described only in developed and high-income Asian countries. We studied the uptake and acceptance of GC and genetic testing services to Asian BRCA carriers in a middle-income country. A total of 363 patients were tested by full sequencing and large rearrangement analysis of both BRCA1 and BRCA2 genes in the Malaysian Breast Cancer (MyBrCa) Genetic Study. Of these, 49 index patients (13.5%) were found to carry deleterious mutations. GC pre- and post- result disclosures were provided and these groups of patients and their families were studied. GC and genetic testing were accepted by 82% of Malaysian patients at high risk for HBOC syndromes. However, risk assessment was limited by large, geographically dispersed, often polygamous or polyandrous families, and the lack of complete cancer registry. Cultural taboos about cancer diagnoses, social marginalization and lack of regulatory control of genetic discrimination were significant concerns. Only 78% of index patients informed their families of their risks and 11% of relatives came forward when offered free counseling and testing. Even when GC and genetic testing are provided at no cost, there remain significant societal and regulatory barriers to effective cancer genetic services in this underserved Asian population. Families believe there is a need for regulatory protection against genetic discrimination. Further studies are needed in the area of increasing awareness about the potential benefits of GC and genetic testing in Asians.
  4. Yip CH, Taib NA, Choo WY, Rampal S, Thong MK, Teo SH
    World J Surg, 2009 Oct;33(10):2077-81.
    PMID: 19649760 DOI: 10.1007/s00268-009-0146-8
    Mutations in BRCA1 and BRCA2 confer an increased risk to breast and other cancers, but to date there have only been limited numbers of studies of BRCA1- and BRCA2-associated cancers among Asians. Malaysia is a multiracial country with three main races: Malays, Chinese, Indians. We determined whether tumor pathologic features and clinical features differ in patients with and without BRCA mutations in this Asian population.
  5. Yip CH, Bhoo Pathy N, Teo SH
    Med. J. Malaysia, 2014 Aug;69 Suppl A:8-22.
    PMID: 25417947 MyJurnal
    Four hundred and nineteen articles related to breast cancer were found in a search through a database dedicated to indexing all original data relevant to medicine published in Malaysia between the years 2000-2013. One hundred and fifty four articles were selected and reviewed on the basis of clinical relevance and future research implications. Overall, Malaysian women have poor survival from breast cancer and it is estimated that half of the deaths due to breast cancer could be prevented. Five-year survival in Malaysia was low and varies among different institutions even within the same disease stage, suggesting an inequity of access to optimal treatment or a lack of compliance to optimal treatment. Malaysian women have poor knowledge of the risk factors, symptoms and methods for early detection of breast cancer, leading to late presentation. Moreover, Malaysian women experience cancer fatalism, belief in alternative medicine, and lack of autonomy in decision making resulting in delays in seeking or avoidance of evidence-based medicine. There are ethnic differences in estrogen receptor status, HER2 overexpression and incidence of triple negative breast cancer which warrant further investigation. Malay women present with larger tumours and at later stages, and even after adjustment for these and other prognostic factors (stage, pathology and treatment), Malay women have a poorer survival. Although the factors responsible for these ethnic differences have not been elucidated, it is thought that pharmacogenomics, lifestyle factors (such as weight-gain, diet and exercise), and psychosocial factors (such as acceptance of 2nd or 3rd line chemotherapy) may be responsible for the difference in survival. Notably, survivorship studies show self-management programmes and exercise improve quality of life, highlighting the need to evaluate the psychosocial impact of breast cancer on Malaysian women, and to design culturally-, religiously- and linguistically-appropriate psycho-education programmes to help women cope with the disease and improve their quality of life. Research done in the Caucasian populations may not necessarily apply to local settings and it is important to embark on local studies particularly prevention, screening, diagnostic, prognostic, therapeutic and psychosocial research.
  6. Yew PY, Mushiroda T, Kiyotani K, Govindasamy GK, Yap LF, Teo SH, et al.
    Mol. Carcinog., 2012 Oct;51 Suppl 1:E74-82.
    PMID: 22213098 DOI: 10.1002/mc.21857
    Nasopharyngeal carcinoma (NPC) is a multifactorial and polygenic disease with high incidence in Asian countries. Epstein-Barr virus infection, environmental and genetic factors are believed to be involved in the tumorigenesis of NPC. The association of single nucleotide polymorphisms (SNPs) in LPLUNC1 and SPLUNC1 genes with NPC was investigated by performing a two-stage case control association study in a Malaysian Chinese population. The initial screening consisted of 81 NPC patients and 147 healthy controls while the replication study consisted of 366 NPC patients and 340 healthy controls. The combined analysis showed that a SNP (rs2752903) of SPLUNC1 was significantly associated with the risk of NPC (combined P = 0.00032, odds ratio = 1.62, 95% confidence interval = 1.25-2.11). In the subsequent dense fine mapping of SPLUNC1 locus, 36 SNPs in strong linkage disequilibrium with rs2752903 (r(2) ≥ 0.85) were associated with NPC susceptibility. Screening of these variants by electrophoretic mobility shift and luciferase reporter assays showed that rs1407019 located in intron 3 (r(2)  = 0.994 with rs2752903) caused allelic difference in the binding of specificity protein 1 (Sp1) transcription factor and affected luciferase activity. This SNP may consequently alter the expression of SPLUNC1 in the epithelial cells. In summary, our study suggested that rs1407019 in intronic enhancer of SPLUNC1 is associated with NPC susceptibility in which its A allele confers an increased risk of NPC in the Malaysian Chinese population.
  7. Yeoh ZY, Jaganathan M, Rajaram N, Rawat S, Tajudeen NA, Rahim N, et al.
    J Glob Oncol, 2018 11;4:1-13.
    PMID: 30398950 DOI: 10.1200/JGO.17.00229
    PURPOSE: Late stage at presentation and poor adherence to treatment remain major contributors to poor survival in low- and middle-income countries (LMICs). Patient navigation (PN) programs in the United States have led to improvement in diagnostic or treatment timeliness, particularly for women in lower socioeconomic classes or minority groups. To date, studies of PN in Asia have been limited. We aimed to assess the feasibility of PN in a state-run hospital in an LMIC and to report the impact on diagnostic and treatment timeliness for patients in its first year of implementation.

    METHODS: We established PN in a dedicated breast clinic of a Malaysian state-run hospital. We compared diagnostic and treatment timeliness between navigated patients (n = 135) and patients diagnosed in the prior year (n = 148), and described factors associated with timeliness.

    RESULTS: Women with PN received timely mammography compared with patients in the prior year (96.4% v 74.4%; P < .001), biopsy (92.5% v 76.1%; P = .003), and communication of news (80.0% v 58.5%; P < .001). PN reduced treatment default rates (4.4% v 11.5%; P = .048). Among navigated patients, late stage at presentation was independently associated with having emotional and language barriers ( P = .01). Finally, the main reason reported for delay, default, or refusal of treatment was the preference for alternative therapy.

    CONCLUSION: PN is feasible for addressing barriers to cancer care when integrated with a state-run breast clinic of an LMIC. Its implementation resulted in improved diagnostic timeliness and reduced treatment default. Wider adoption of PN could be a key element of cancer control in LMICs.

  8. Yap LF, Ahmad M, Zabidi MM, Chu TL, Chai SJ, Lee HM, et al.
    Int. J. Oncol., 2014 May;44(5):1774-80.
    PMID: 24626628 DOI: 10.3892/ijo.2014.2342
    The molecular events that drive the progression of Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) are still to be elucidated. Here, we report for the first time the pathogenic significance of an NPC-associated gene, wingless-type MMTV integration site family, member 5A (WNT5A) and the contribution of EBV to its expression. WNT5A is a representative Wnt protein that activates non-canonical Wnt signalling. With regard to its role in carcinogenesis, there is conflicting evidence as to whether WNT5A has a tumour-promoting or tumour-suppressive role. We show that WNT5A is upregulated in primary NPC tissue samples. We also demonstrate that WNT5A expression was dramatically increased in NPC cell lines expressing the EBV-encoded LMP2A gene, suggesting that this EBV-encoded latent gene is responsible for upregulating WNT5A in NPC. In addition, in vitro WNT5A overexpression promotes the proliferation, migration and invasion of NPC cells. Our results not only reveal pro-tumorigenic effects of WNT5A in NPC but also suggest that WNT5A could be an important therapeutic target in patients with EBV-associated disease.
  9. Yang Y, Shu X, Shu XO, Bolla MK, Kweon SS, Cai Q, et al.
    EBioMedicine, 2019 Oct;48:203-211.
    PMID: 31629678 DOI: 10.1016/j.ebiom.2019.09.006
    BACKGROUND: We previously conducted a systematic field synopsis of 1059 breast cancer candidate gene studies and investigated 279 genetic variants, 51 of which showed associations. The major limitation of this work was the small sample size, even pooling data from all 1059 studies. Thereafter, genome-wide association studies (GWAS) have accumulated data for hundreds of thousands of subjects. It's necessary to re-evaluate these variants in large GWAS datasets.

    METHODS: Of these 279 variants, data were obtained for 228 from GWAS conducted within the Asian Breast Cancer Consortium (24,206 cases and 24,775 controls) and the Breast Cancer Association Consortium (122,977 cases and 105,974 controls of European ancestry). Meta-analyses were conducted to combine the results from these two datasets.

    FINDINGS: Of those 228 variants, an association was observed for 12 variants in 10 genes at a Bonferroni-corrected threshold of P 

  10. Yang Y, Wu L, Shu X, Lu Y, Shu XO, Cai Q, et al.
    Cancer Res., 2019 02 01;79(3):505-517.
    PMID: 30559148 DOI: 10.1158/0008-5472.CAN-18-2726
    DNA methylation is instrumental for gene regulation. Global changes in the epigenetic landscape have been recognized as a hallmark of cancer. However, the role of DNA methylation in epithelial ovarian cancer (EOC) remains unclear. In this study, high-density genetic and DNA methylation data in white blood cells from the Framingham Heart Study (N = 1,595) were used to build genetic models to predict DNA methylation levels. These prediction models were then applied to the summary statistics of a genome-wide association study (GWAS) of ovarian cancer including 22,406 EOC cases and 40,941 controls to investigate genetically predicted DNA methylation levels in association with EOC risk. Among 62,938 CpG sites investigated, genetically predicted methylation levels at 89 CpG were significantly associated with EOC risk at a Bonferroni-corrected threshold of P < 7.94 × 10-7. Of them, 87 were located at GWAS-identified EOC susceptibility regions and two resided in a genomic region not previously reported to be associated with EOC risk. Integrative analyses of genetic, methylation, and gene expression data identified consistent directions of associations across 12 CpG, five genes, and EOC risk, suggesting that methylation at these 12 CpG may influence EOC risk by regulating expression of these five genes, namely MAPT, HOXB3, ABHD8, ARHGAP27, and SKAP1. We identified novel DNA methylation markers associated with EOC risk and propose that methylation at multiple CpG may affect EOC risk via regulation of gene expression. SIGNIFICANCE: Identification of novel DNA methylation markers associated with EOC risk suggests that methylation at multiple CpG may affect EOC risk through regulation of gene expression.
  11. Yang X, Leslie G, Doroszuk A, Schneider S, Allen J, Decker B, et al.
    J. Clin. Oncol., 2020 Mar 01;38(7):674-685.
    PMID: 31841383 DOI: 10.1200/JCO.19.01907
    PURPOSE: To estimate age-specific relative and absolute cancer risks of breast cancer and to estimate risks of ovarian, pancreatic, male breast, prostate, and colorectal cancers associated with germline PALB2 pathogenic variants (PVs) because these risks have not been extensively characterized.

    METHODS: We analyzed data from 524 families with PALB2 PVs from 21 countries. Complex segregation analysis was used to estimate relative risks (RRs; relative to country-specific population incidences) and absolute risks of cancers. The models allowed for residual familial aggregation of breast and ovarian cancer and were adjusted for the family-specific ascertainment schemes.

    RESULTS: We found associations between PALB2 PVs and risk of female breast cancer (RR, 7.18; 95% CI, 5.82 to 8.85; P = 6.5 × 10-76), ovarian cancer (RR, 2.91; 95% CI, 1.40 to 6.04; P = 4.1 × 10-3), pancreatic cancer (RR, 2.37; 95% CI, 1.24 to 4.50; P = 8.7 × 10-3), and male breast cancer (RR, 7.34; 95% CI, 1.28 to 42.18; P = 2.6 × 10-2). There was no evidence for increased risks of prostate or colorectal cancer. The breast cancer RRs declined with age (P for trend = 2.0 × 10-3). After adjusting for family ascertainment, breast cancer risk estimates on the basis of multiple case families were similar to the estimates from families ascertained through population-based studies (P for difference = .41). On the basis of the combined data, the estimated risks to age 80 years were 53% (95% CI, 44% to 63%) for female breast cancer, 5% (95% CI, 2% to 10%) for ovarian cancer, 2%-3% (95% CI females, 1% to 4%; 95% CI males, 2% to 5%) for pancreatic cancer, and 1% (95% CI, 0.2% to 5%) for male breast cancer.

    CONCLUSION: These results confirm PALB2 as a major breast cancer susceptibility gene and establish substantial associations between germline PALB2 PVs and ovarian, pancreatic, and male breast cancers. These findings will facilitate incorporation of PALB2 into risk prediction models and optimize the clinical cancer risk management of PALB2 PV carriers.

  12. Wyszynski A, Hong CC, Lam K, Michailidou K, Lytle C, Yao S, et al.
    Hum. Mol. Genet., 2016 09 01;25(17):3863-3876.
    PMID: 27402876 DOI: 10.1093/hmg/ddw223
    Breast cancer is the most diagnosed malignancy and the second leading cause of cancer mortality in females. Previous association studies have identified variants on 2q35 associated with the risk of breast cancer. To identify functional susceptibility loci for breast cancer, we interrogated the 2q35 gene desert for chromatin architecture and functional variation correlated with gene expression. We report a novel intergenic breast cancer risk locus containing an enhancer copy number variation (enCNV; deletion) located approximately 400Kb upstream to IGFBP5, which overlaps an intergenic ERα-bound enhancer that loops to the IGFBP5 promoter. The enCNV is correlated with modified ERα binding and monoallelic-repression of IGFBP5 following oestrogen treatment. We investigated the association of enCNV genotype with breast cancer in 1,182 cases and 1,362 controls, and replicate our findings in an independent set of 62,533 cases and 60,966 controls from 41 case control studies and 11 GWAS. We report a dose-dependent inverse association of 2q35 enCNV genotype (percopy OR = 0.68 95%CI 0.55-0.83, P = 0.0002; replication OR = 0.77 95% CI 0.73-0.82, P = 2.1 × 10-19) and identify 13 additional linked variants (r2 > 0.8) in the 20Kb linkage block containing the enCNV (P = 3.2 × 10-15 - 5.6 × 10-17). These associations were independent of previously reported 2q35 variants, rs13387042/rs4442975 and rs16857609, and were stronger for ER-positive than ER-negative disease. Together, these results suggest that 2q35 breast cancer risk loci may be mediating their effect through IGFBP5.
  13. Wen WX, Allen J, Lai KN, Mariapun S, Hasan SN, Ng PS, et al.
    J. Med. Genet., 2018 02;55(2):97-103.
    PMID: 28993434 DOI: 10.1136/jmedgenet-2017-104947
    BACKGROUND: Genetic testing for BRCA1 and BRCA2 is offered typically to selected women based on age of onset and family history of cancer. However, current internationally accepted genetic testing referral guidelines are built mostly on data from cancer genetics clinics in women of European descent. To evaluate the appropriateness of such guidelines in Asians, we have determined the prevalence of germ line variants in an unselected cohort of Asian patients with breast cancer and healthy controls.

    METHODS: Germ line DNA from a hospital-based study of 2575 unselected patients with breast cancer and 2809 healthy controls were subjected to amplicon-based targeted sequencing of exonic and proximal splice site junction regions of BRCA1 and BRCA2 using the Fluidigm Access Array system, with sequencing conducted on a Illumina HiSeq2500 platform. Variant calling was performed with GATK UnifiedGenotyper and were validated by Sanger sequencing.

    RESULTS: Fifty-five (2.1%) BRCA1 and 66 (2.6%) BRCA2 deleterious mutations were identified among patients with breast cancer and five (0.18%) BRCA1 and six (0.21%) BRCA2 mutations among controls. One thousand one hundred and eighty-six (46%) patients and 97 (80%) carriers fulfilled the National Comprehensive Cancer Network guidelines for genetic testing.

    CONCLUSION: Five per cent of unselected Asian patients with breast cancer carry deleterious variants in BRCA1 or BRCA2. While current referral guidelines identified the majority of carriers, one in two patients would be referred for genetic services. Given that such services are largely unavailable in majority of low-resource settings in Asia, our study highlights the need for more efficient guidelines to identify at-risk individuals in Asia.

  14. Wen WX, Soo JS, Kwan PY, Hong E, Khang TF, Mariapun S, et al.
    Breast Cancer Res., 2016 05 27;18(1):56.
    PMID: 27233495 DOI: 10.1186/s13058-016-0717-1
    BACKGROUND: APOBEC3B is a cytosine deaminase implicated in immune response to viral infection, cancer predisposition and carcinogenesis. Germline APOBEC3B deletion is more common in East Asian women and confers a modest risk to breast cancer in both East Asian and Caucasian women. Analysis of tumour samples from women of European descent has shown that germline APOBEC3B deletion is associated with an increased propensity to develop somatic mutations and with an enrichment for immune response-related gene sets. However, this has not been examined in Asian tumour samples, where population differences in genetic and dietary factors may have an impact on the immune system.

    METHODS: In this study, we determined the prevalence of germline APOBEC3B deletion and its association with breast cancer risk in a cross-sectional hospital-based Asian multi-ethnic cohort of 1451 cases and 1442 controls from Malaysia. We compared gene expression profiles of breast cancers arising from APOBEC3B deletion carriers and non-carriers using microarray analyses. Finally, we characterised the overall abundance of tumour-infiltrating immune cells in breast cancers from TCGA and METABRIC using ESTIMATE and relative frequency of 22 immune cell subsets in breast cancers from METABRIC using CIBERSORT.

    RESULTS: The minor allelic frequency of APOBEC3B deletion was estimated to be 0.35, 0.42 and 0.16 in female populations of Chinese, Malay and Indian descent, respectively, and that germline APOBEC3B deletion was associated with breast cancer risk with odds ratios of 1.23 (95 % CI: [1.05, 1.44]) for one-copy deletion and 1.38 (95 % CI: [1.10, 1.74]) for two-copy deletion compared to women with no deletion. Germline APOBEC3B deletion was not associated with any clinicopathologic features or the expression of any APOBEC family members but was associated with immune response-related gene sets (FDR q values 

  15. Wen W, Shu XO, Guo X, Cai Q, Long J, Bolla MK, et al.
    Breast Cancer Res., 2016 12 08;18(1):124.
    PMID: 27931260
    BACKGROUND: Approximately 100 common breast cancer susceptibility alleles have been identified in genome-wide association studies (GWAS). The utility of these variants in breast cancer risk prediction models has not been evaluated adequately in women of Asian ancestry.

    METHODS: We evaluated 88 breast cancer risk variants that were identified previously by GWAS in 11,760 cases and 11,612 controls of Asian ancestry. SNPs confirmed to be associated with breast cancer risk in Asian women were used to construct a polygenic risk score (PRS). The relative and absolute risks of breast cancer by the PRS percentiles were estimated based on the PRS distribution, and were used to stratify women into different levels of breast cancer risk.

    RESULTS: We confirmed significant associations with breast cancer risk for SNPs in 44 of the 78 previously reported loci at P 

  16. Vigorito E, Kuchenbaecker KB, Beesley J, Adlard J, Agnarsson BA, Andrulis IL, et al.
    PLoS ONE, 2016;11(7):e0158801.
    PMID: 27463617 DOI: 10.1371/journal.pone.0158801
    Population-based genome wide association studies have identified a locus at 9p22.2 associated with ovarian cancer risk, which also modifies ovarian cancer risk in BRCA1 and BRCA2 mutation carriers. We conducted fine-scale mapping at 9p22.2 to identify potential causal variants in BRCA1 and BRCA2 mutation carriers. Genotype data were available for 15,252 (2,462 ovarian cancer cases) BRCA1 and 8,211 (631 ovarian cancer cases) BRCA2 mutation carriers. Following genotype imputation, ovarian cancer associations were assessed for 4,873 and 5,020 SNPs in BRCA1 and BRCA 2 mutation carriers respectively, within a retrospective cohort analytical framework. In BRCA1 mutation carriers one set of eight correlated candidate causal variants for ovarian cancer risk modification was identified (top SNP rs10124837, HR: 0.73, 95%CI: 0.68 to 0.79, p-value 2× 10-16). These variants were located up to 20 kb upstream of BNC2. In BRCA2 mutation carriers one region, up to 45 kb upstream of BNC2, and containing 100 correlated SNPs was identified as candidate causal (top SNP rs62543585, HR: 0.69, 95%CI: 0.59 to 0.80, p-value 1.0 × 10-6). The candidate causal in BRCA1 mutation carriers did not include the strongest associated variant at this locus in the general population. In sum, we identified a set of candidate causal variants in a region that encompasses the BNC2 transcription start site. The ovarian cancer association at 9p22.2 may be mediated by different variants in BRCA1 mutation carriers and in the general population. Thus, potentially different mechanisms may underlie ovarian cancer risk for mutation carriers and the general population.
  17. Ugai T, Milne RL, Ito H, Aronson KJ, Bolla MK, Chan T, et al.
    Mol Genet Genomic Med, 2019 Jun;7(6):e707.
    PMID: 31066241 DOI: 10.1002/mgg3.707
    BACKGROUND: Epidemiological studies consistently indicate that alcohol consumption is an independent risk factor for female breast cancer (BC). Although the aldehyde dehydrogenase 2 (ALDH2) polymorphism (rs671: Glu>Lys) has a strong effect on acetaldehyde metabolism, the association of rs671 with BC risk and its interaction with alcohol intake have not been fully elucidated. We conducted a pooled analysis of 14 case-control studies, with individual data on Asian ancestry women participating in the Breast Cancer Association Consortium.

    METHODS: We included 12,595 invasive BC cases and 12,884 controls for the analysis of rs671 and BC risk, and 2,849 invasive BC cases and 3,680 controls for the analysis of the gene-environment interaction between rs671 and alcohol intake for BC risk. The pooled odds ratios (OR) with 95% confidence intervals (CI) associated with rs671 and its interaction with alcohol intake for BC risk were estimated using logistic regression models.

    RESULTS: The Lys/Lys genotype of rs671 was associated with increased BC risk (OR = 1.16, 95% CI 1.03-1.30, p = 0.014). According to tumor characteristics, the Lys/Lys genotype was associated with estrogen receptor (ER)-positive BC (OR = 1.19, 95% CI 1.05-1.36, p = 0.008), progesterone receptor (PR)-positive BC (OR = 1.19, 95% CI 1.03-1.36, p = 0.015), and human epidermal growth factor receptor 2 (HER2)-negative BC (OR = 1.25, 95% CI 1.05-1.48, p = 0.012). No evidence of a gene-environment interaction was observed between rs671 and alcohol intake (p = 0.537).

    CONCLUSION: This study suggests that the Lys/Lys genotype confers susceptibility to BC risk among women of Asian ancestry, particularly for ER-positive, PR-positive, and HER2-negative tumor types.

  18. Toh GT, Kang P, Lee SS, Lee DS, Lee SY, Selamat S, et al.
    PLoS ONE, 2008;3(4):e2024.
    PMID: 18431501 DOI: 10.1371/journal.pone.0002024
    BACKGROUND: In Asia, breast cancer is characterised by an early age of onset: In Malaysia, approximately 50% of cases occur in women under the age of 50 years. A proportion of these cases may be attributable, at least in part, to genetic components, but to date, the contribution of genetic components to breast cancer in many of Malaysia's ethnic groups has not been well-characterised.
    METHODOLOGY: Given that hereditary breast carcinoma is primarily due to germline mutations in one of two breast cancer susceptibility genes, BRCA1 and BRCA2, we have characterised the spectrum of BRCA mutations in a cohort of 37 individuals with early-onset disease (
  19. Thirthagiri E, Cheong LS, Yip CH, Teo SH
    Fam. Cancer, 2009;8(4):355-8.
    PMID: 19399639 DOI: 10.1007/s10689-009-9244-x
    A truncating mutation (1100delC) in the cell cycle checkpoint kinase-2 gene, CHEK2, has been identified as a risk factor for familial and sporadic breast cancer in some Northern and Western European populations. However, the prevalence of CHEK2*1100delC in breast cancer appears to be population dependent. We analysed the prevalence of CHEK2*1100delC in 668 breast cancer cases, of which 542 were invasive breast cancers, from a hospital-based cohort of breast cancer patients from Kuala Lumpur, Malaysia. The variant was not found in any patients in this cohort, suggesting that CHEK2*1100delC is rare in our population, and unlikely to contribute significantly to risk to breast cancer among the Malay, Chinese and Indian ethnic groups in Malaysia. This suggests that screening for this allele should not be routinely conducted in Malaysia.
  20. Thirthagiri E, Lee SY, Kang P, Lee DS, Toh GT, Selamat S, et al.
    Breast Cancer Res., 2008;10(4):R59.
    PMID: 18627636 DOI: 10.1186/bcr2118
    The cost of genetic testing and the limited knowledge about the BRCA1 and BRCA2 genes in different ethnic groups has limited its availability in medium- and low-resource countries, including Malaysia. In addition, the applicability of many risk-assessment tools, such as the Manchester Scoring System and BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) which were developed based on mutation rates observed primarily in Caucasian populations using data from multiplex families, and in populations where the rate of breast cancer is higher, has not been widely tested in Asia or in Asians living elsewhere. Here, we report the results of genetic testing for mutations in the BRCA1 or BRCA2 genes in a series of families with breast cancer in the multi-ethnic population (Malay, Chinese and Indian) of Malaysia.
Contact Us

Please provide feedback to Administrator (tengcl@gmail.com)

External Links