Ava Kwong

Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong

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Publications (109)540.92 Total impact

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    ABSTRACT: Background: Compared with male surgeons, women have less success advancing their careers and are underrepresented in leadership positions in surgery. The purpose of this study is to identify the qualifications necessary to become leaders in surgery and the career barriers faced by women surgeons in various cultural environments. Methods: A survey was performed with women surgeons in Japan, USA, Finland, and Hong Kong, China, to assess various barriers faced by women surgeons in the respective countries. To develop appropriate survey tool, a preliminary questionnaire was distributed to leaders in surgery and also in various organizations worldwide. Results: The response rate was 23 % with 225 of 964 survey returned. Japanese women surgeons identify lacked family support as impeding a successful surgical career. US women surgeons feel more latent gender discrimination. Finnish women surgeons are less likely to need to sacrifice work-life balance, when holding leadership positions. Women surgeons worldwide are highly motivated to develop their career and agree the percentage of women surgeons in leadership positions should be increased. Conclusions: Women surgeons in different countries perceive different challenges. We must develop strategies and should not hesitate to negotiate to overcome these issues to reach leadership positions in surgery. This may be accomplished through networking worldwide to improve current conditions and obstacles.
    World Journal of Surgery 11/2015; DOI:10.1007/s00268-015-3332-x · 2.64 Impact Factor
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    ABSTRACT: Background: BRCA1/BRCA2 mutations are associated with an increased lifetime risk for hereditary breast and ovarian cancer (HBOC). Compared with the Western developed countries, genetic testing and risk assessment for HBOC in Asia are less available, thus prohibiting the appropriate surveillance, clinical strategies and cancer management. Methods: The current status of HBOC management in 14 Asian countries, including genetic counselling/testing uptakes and clinical management options, was reviewed. We analysed how economic factors, healthcare and legal frameworks, and cultural issues affect the genetic service availability in Asia. Results: In 2012, only an estimated 4,000 breast cancer cases from 14 Asian countries have benefited from genetic services. Genetic testing costs and the absence of their adoption into national healthcare systems are the main economic barriers for approaching genetic services. Training programmes, regional accredited laboratories and healthcare professionals are not readily available in most of the studied countries. A lack of legal frameworks against genetic discrimination and a lack of public awareness of cancer risk assessment also provide challenges to HBOC management in Asia. Conclusions: The Asian BRCA Consortium reports the current disparities in genetic services for HBOC in Asia and urges the policy makers, healthcare sectors and researchers to address the limitations in HBOC management.
    Public Health Genomics 11/2015; DOI:10.1159/000441714 · 2.21 Impact Factor
  • Xin Liu · Ava Kwong · Alan Sihoe · Kent-Man Chu ·
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    ABSTRACT: It was reported that circulating microRNAs could be applied as non-invasive biomarkers for cancer monitoring. The purpose of this study was to identify plasma miRNA that may serve as a novel biomarker for gastric cancer and to evaluate its clinical application. MicroRNA profiles were generated from plasma samples of 5 patients with gastric cancer (GC) versus 5 healthy controls (HC). MicroRNA-940 (miR-940) was one of the most downregulated miRNAs with fold change of 0.164. It was revealed that the expression of miR-940 was downregulated in both the initial set (N = 30, P < 0.0001) and the validation set (N = 80, P < 0.0001) of plasma samples of patients with gastric cancer. The sensitivity was obviously higher than the current biomarkers CEA and CA19-9 (81.25 % vs. 22.54 % and 15.71 %). MiR-940 was also significantly downregulated in gastric cancer tissue samples (N = 34, P = 0.0015), as well as in cancer cell lines (N = 7). Importantly, miR-940 was significantly highly expressed in stomach tissue samples than in other types of tissue samples including the liver, breast, thyroid, and lung. Moreover, there was a trend of lower expression of miR-940 from early to advanced stage of gastric cancer. Target prediction suggested that miR-940 regulated cell signaling including NF-κB and Wnt/β-catenin, as well as pathways of cell communication and adhesion. These pathways play critical roles in gastric cancer initiation and progression. It is the first report that miR-940 may mainly express in the stomach. Downregulation of plasma miR-940 may serve as a novel biomarker for detection of gastric cancer.
    Tumor Biology 10/2015; DOI:10.1007/s13277-015-4019-5 · 3.61 Impact Factor
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    ABSTRACT: Availability and implementation: Freely Available at database.bio CONTACT: twlam@cs.hku.hk, rb@l3-bioinfo.com SUPPLEMENTARY INFORMATION: Available at Bioinformatics online.
    Bioinformatics 08/2015; DOI:10.1093/bioinformatics/btv500 · 4.98 Impact Factor

  • Cancer Research 08/2015; 75(15 Supplement):3105-3105. DOI:10.1158/1538-7445.AM2015-3105 · 9.33 Impact Factor
  • Lorraine Chow · Dacita Suen · Kwok Kuen Ma · Ava Kwong ·
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    ABSTRACT: Brain metastasis occurs in 10-15% of metastatic breast cancer patients and is associated with poor prognosis. This study aims to identify tumor characteristics of primary breast cancer, which are related to brain metastases in Hong Kong Chinese patients. A retrospective study of patients with invasive breast cancer receiving treatment in a university hospital from January 2001 to December 2008 was performed. The clinicopathological factors of patients with brain metastases were analyzed and compared with those who had no brain metastasis. Risk factors for brain metastasis were identified by univariate analysis first and then by multivariate analysis. A total of 912 patients with invasive breast cancer were treated during the study period. Of these, 30 patients were found to have distant metastases to brain. Patients with brain metastases had more breast tumors of higher histological grade (Grade III, 78.9% vs. 30.2%; p = 0.001). Their tumors also had a significantly higher rate of negative estrogen receptors (78.9% vs. 30.2%, p = 0.001). On multivariate analysis, only high tumor grading was found to be predictive of developing brain metastasis. Chinese breast cancer patients with brain metastasis were more likely to have high-grade tumors and negative estrogen receptor status. A more vigorous surveillance program for the central nervous system should be considered for this group of patients. Copyright © 2015. Published by Elsevier Taiwan.
    07/2015; 38(4). DOI:10.1016/j.asjsur.2015.03.003
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    ABSTRACT: Approximately 5%-10% of breast cancers are due to genetic predisposition caused by germline mutations; the most commonly tested genes are BRCA1 and BRCA2 mutations. Some mutations are unique to one family and others are recurrent; the spectrum of BRCA1/BRCA2 mutations varies depending on the geographical origins, populations or ethnic groups. In this review, we compiled data from 11 participating Asian countries (Bangladesh, Mainland China, Hong Kong SAR, Indonesia, Japan, Korea, Malaysia, Philippines, Singapore, Thailand and Vietnam), and from ethnic Asians residing in Canada and the USA. We have additionally conducted a literature review to include other Asian countries mainly in Central and Western Asia. We present the current pathogenic mutation spectrum of BRCA1/BRCA2 genes in patients with breast cancer in various Asian populations. Understanding BRCA1/BRCA2 mutations in Asians will help provide better risk assessment and clinical management of breast cancer. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    Journal of Medical Genetics 07/2015; DOI:10.1136/jmedgenet-2015-103132 · 6.34 Impact Factor
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    ABSTRACT: A diagnosis of advanced breast cancer (ABC) challenges a woman's ambitions. This longitudinal study explored (1) if goal adjustment disposition influenced psychological adjustment patterns among women with ABC and (2) if dispositional hope and optimism moderate effects of goal adjustment on psychological adjustment. One hundred ninety three out of 225 women with ABC were assessed while they were awaiting/receiving initial chemotherapy, then again at 6 weeks, 3 months, 6 months, and 12 months post-baseline. Goal disengagement, goal reengagement, optimism, hope, and psychological adjustment (anxiety, depression, and positive affect) were assessed at baseline; psychological adjustment was reassessed at each follow-up. Latent growth curve modeling was used to examine the change of psychological adjustment and test the study objectives. High goal disengagement, low reengagement, and high optimism were associated with lower initial anxiety, while high goal disengagement and optimism predicted a slower rate of change in anxiety. High goal disengagement, reengagement, and optimism were associated with lower initial depression. High goal reengagement, optimism, and hope were associated with initial positive affect scores, while optimism predicted its rate of change. Optimism moderated the effect of goal disengagement on anxiety and depression, whereas hope moderated the effect of goal reengagement on positive affect. Goal disengagement and reengagement are two relatively independent processes influencing psychological well-being. These findings will help clinicians to tailor specific interventions to help women coping with the diagnosis of ABC. Copyright © 2015 John Wiley & Sons, Ltd.
    Psycho-Oncology 06/2015; DOI:10.1002/pon.3871 · 2.44 Impact Factor
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    ABSTRACT: Germline BRCA gene mutations are reportedly associated with hereditary breast and ovarian cancers. Identification of BRCA mutations greatly improves the preventive strategies and management of breast cancer. Sanger sequencing has been the gold standard in identifying these mutations. However, 4-28% of inherited BRCA mutations may be due to large genomic rearrangements (LGRs), which could be missed by using Sanger sequencing alone. Our aim is to evaluate the pick-up rate of LGRs in our cohort. A total of 1,236 clinically high-risk patients with breast and/or ovarian cancers were recruited through The Hong Kong Hereditary Breast Cancer Family Registry from 2007 to 2014. Full gene sequencing (either Sanger or next generation sequencing) and multiplex ligation-dependent probe amplification (MLPA) were performed. We identified 120 deleterious BRCA mutations: 57 (4.61%) were in BRCA1 and 63 (5.10%) were in BRCA2. LGRs accounted for 6.67% (8 of 120) of all BRCA mutations, whereas 8.77 % (5 of 57) were BRCA1 mutations and 4.76% (3 of 63) were BRCA2 mutations. Through this integrated approach, both small nucleotide variations and LGRs could be detected. We suggest that MLPA should be incorporated into the standard practice for genetic testing to avoid false-negative results, which would greatly affect the management of these high-risk families. Copyright © 2015 Elsevier Inc. All rights reserved.
    Cancer Genetics 06/2015; 208(9). DOI:10.1016/j.cancergen.2015.05.031 · 2.98 Impact Factor

  • Cancer Research 05/2015; 75(9 Supplement):P3-07-32-P3-07-32. DOI:10.1158/1538-7445.SABCS14-P3-07-32 · 9.33 Impact Factor

  • Cancer Research 05/2015; 75(9 Supplement):P2-07-07-P2-07-07. DOI:10.1158/1538-7445.SABCS14-P2-07-07 · 9.33 Impact Factor
  • V Y Shin · J M Siu · I Cheuk · E K O Ng · A Kwong ·
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    ABSTRACT: Triple-negative breast cancer (TNBC) accounts for 15-20% of all breast cancer in women globally. This subtype often has early and high recurrence rates resulting in poor survival, partially due to lack of targeted therapies. Therefore, there is an urgent need to identify TNBC-specific biomarkers for early diagnosis and treatment monitoring, and to develop more effective targeted therapy. By using miRCURY LNA array platform, we compared the differential miRNA expressions in plasma of patient with TNBC (n=5) and non-TNBC (n=5), as well as healthy controls (n=5). Potential miRNAs were then validated in a large cohort of patients by real-time PCR. Ten putative miRNAs from the microarray data that differentially expressed between non-TNBC and healthy controls were identified. In the screening phase (n=90), we selected five miRNAs (miR-92a-3p, miR-342-3p, miR-16, miR-21 and miR-199a-5p) that could discriminate TNBC from non-TNBC for further validation. Results showed that miR-16, miR-21 and miR-199a-5p were underexpressed in TNBC when compared with non-TNBC, and were further validated in a large cohort (n=252). In addition, post-operative plasma levels of miR-16, miR-21 and miR-199a-5p were significantly restored when compared with pre-operative plasma of TNBC. Plasma miR-199a-5p expression in TNBC had significant difference when compared with non-TNBC and healthy controls, the receiver-operator characteristics curve analysis revealed the highest area under curve (AUC=0.8838) among all. The expression levels were associated with TNM stage and tumour subtypes. Our data suggest that miR-199a-5p could be a TNBC-specific marker with diagnostic value and provide insights into targeted therapy in the treatment of TNBC.British Journal of Cancer advance online publication, 23 April 2015; doi:10.1038/bjc.2015.143 www.bjcancer.com.
    British Journal of Cancer 04/2015; 112(11). DOI:10.1038/bjc.2015.143 · 4.84 Impact Factor
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    ABSTRACT: IMPORTANCE: Limited information about the relationship between specific mutations in BRCA1 or BRCA2 (BRCA1/2) and cancer risk exists. OBJECTIVE:To identify mutation-specific cancer risks for carriers of BRCA1/2. DESIGN, SETTING, AND PARTICIPANTS:Observational study of women who were ascertained between 1937 and 2011 (median, 1999) and found to carry disease-associated BRCA1 or BRCA2 mutations. The international sample comprised 19,581 carriers of BRCA1 mutations and 11,900 carriers of BRCA2 mutations from 55 centers in 33 countries on 6 continents. We estimated hazard ratios for breast and ovarian cancer based on mutation type, function, and nucleotide position. We also estimated RHR, the ratio of breast vs ovarian cancer hazard ratios. A value of RHR greater than 1 indicated elevated breast cancer risk; a value of RHR less than 1 indicated elevated ovarian cancer risk. EXPOSURES:Mutations of BRCA1 or BRCA2. MAIN OUTCOMES AND MEASURES: Breast and ovarian cancer risks. RESULTS:Among BRCA1 mutation carriers, 9052 women (46%) were diagnosed with breast cancer, 2317 (12%) with ovarian cancer, 1041 (5%) with breast and ovarian cancer, and 7171 (37%) without cancer. Among BRCA2 mutation carriers, 6180 women (52%) were diagnosed with breast cancer, 682 (6%) with ovarian cancer, 272 (2%) with breast and ovarian cancer, and 4766 (40%) without cancer. In BRCA1, we identified 3 breast cancer cluster regions (BCCRs) located at c.179 to c.505 (BCCR1; RHR = 1.46; 95% CI, 1.22-1.74; P = 2 × 10(-6)), c.4328 to c.4945 (BCCR2; RHR = 1.34; 95% CI, 1.01-1.78; P = .04), and c. 5261 to c.5563 (BCCR2', RHR = 1.38; 95% CI, 1.22-1.55; P = 6 × 10(-9)). We also identified an ovarian cancer cluster region (OCCR) from c.1380 to c.4062 (approximately exon 11) with RHR = 0.62 (95% CI, 0.56-0.70; P = 9 × 10(-17)). In BRCA2, we observed multiple BCCRs spanning c.1 to c.596 (BCCR1; RHR = 1.71; 95% CI, 1.06-2.78; P = .03), c.772 to c.1806 (BCCR1'; RHR = 1.63; 95% CI, 1.10-2.40; P = .01), and c.7394 to c.8904 (BCCR2; RHR = 2.31; 95% CI, 1.69-3.16; P = .00002). We also identified 3 OCCRs: the first (OCCR1) spanned c.3249 to c.5681 that was adjacent to c.5946delT (6174delT; RHR = 0.51; 95% CI, 0.44-0.60; P = 6 × 10(-17)). The second OCCR spanned c.6645 to c.7471 (OCCR2; RHR = 0.57; 95% CI, 0.41-0.80; P = .001). Mutations conferring nonsense-mediated decay were associated with differential breast or ovarian cancer risks and an earlier age of breast cancer diagnosis for both BRCA1 and BRCA2 mutation carriers. CONCLUSIONS AND RELEVANCE: Breast and ovarian cancer risks varied by type and location of BRCA1/2 mutations. With appropriate validation, these data may have implications for risk assessment and cancer prevention decision making for carriers of BRCA1 and BRCA2 mutations.
    JAMA The Journal of the American Medical Association 04/2015; 313(13):1347-61. DOI:10.1001/jama.2014.5985 · 35.29 Impact Factor
  • A. Kwong · J. Chen · V. Shin · F. Law · T. Chan · J. Ford ·

    The Breast 03/2015; 24:S73. DOI:10.1016/S0960-9776(15)70182-7 · 2.38 Impact Factor
  • M. Siu · J. Ho · I. Chuek · J. Chen · A. Kwong · V. Shin ·

    The Breast 03/2015; 24:S42-S43. DOI:10.1016/S0960-9776(15)70097-4 · 2.38 Impact Factor
  • Michael Co · Ava Kwong ·
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    ABSTRACT: In patients with negative sentinel lymph node biopsy (SLNB), axillary dissection (AD) can be avoided to reduce morbidities. However, there is only limited data on the rate of positive non-SLN (NSLN) in those who have micrometastasis and isolated tumor cells (ITC) in the literature. We did a retrospective review of all clinically node-negative breast cancer patients with SLNB done at our unit from January 2001 to June 2011. Multivariate analysis was adopted to evaluate the risk factors for NSLN metastasis. Difference in 5-year disease-free survival (DFS) was evaluated with log-rank test. Five-hundred and thirty-seven patients underwent SLNB; 161 (30 %) had positive SLN on frozen section (FS), 50 of these patients (31 %) had NSLN metastasis, 25 patients had negative SLN on FS but were found to have micrometastasis on histopathology, and only 1 (4 %) of them had NSLN metastasis, while 14 patients were found to have ITC in SLN; none of them had NSLN metastasis. Multivariate analysis found that the number of SLN harboring micrometastasis is the only independent risk factor for NSLN metastasis in patients with micrometastasis (p value = 0.008). On the contrary; tumor size, grade, and biology were not associated with NSLN metastasis. 5-year DFS in patients with macrometastasis in SLN was 94.2 %, while that in patients with micrometastasis and ITC was 100 % (p value <0.001). NSLN metastasis in those who only have micrometastasis and ITC is rare, and 5-year DFS is significantly better in this group of patients as well. It is therefore a routine practice in our unit to omit AD in patients with micrometastasis and ITC on SLN.
    World Journal of Surgery 02/2015; 39(6). DOI:10.1007/s00268-015-2984-x · 2.64 Impact Factor
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    ABSTRACT: MicroRNAs (miRs) have been shown to play important roles in tumour progression. Their expression pattern can be useful for cancer classification. However, little about miRs is known in mammary phyllodes tumors (PT). In this study, a PCR based miR profiling was performed in a small PT cohort to identify deregulated miRs in malignant PT. The purported roles and targets of these miRs were further validated. Unsupervised clustering of miR expression profiling segregated PT into different grades, implicating miR profile in PT classification. Among the deregulated miRs, miR-21, miR-335 and miR-155 were validated to be higher in malignant than lower grades PT in the independent cohort by qPCR (p≤0.032). Their expression correlated with some of the malignant histologic features, including high stromal cellularity, nuclear pleomorphism and mitosis. Subsequent analysis of their downstream proteins, viz. PTEN for miR-21/ miR-155 and Rb for miR-335 also showed independent significant negative association between miR and protein expression. Differential expression of miRs in PT could be useful in diagnosis and grading of PT. Their deregulated expression together with the altered downstream targets implicated their active involvement in PT malignant transformation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Histopathology 01/2015; 67(3). DOI:10.1111/his.12648 · 3.45 Impact Factor
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    ABSTRACT: AluScan combines inter-Alu PCR using multiple Alu-based primers with opposite orientations and next-generation sequencing to capture a huge number of Alu-proximal genomic sequences for investigation. Its requirement of only sub-microgram quantities of DNA facilitates the examination of large numbers of samples. However, the special features of AluScan data rendered difficult the calling of copy number variation (CNV) directly using the calling algorithms designed for whole genome sequencing (WGS) or exome sequencing. In this study, an AluScanCNV package has been assembled for efficient CNV calling from AluScan sequencing data employing a Geary-Hinkley transformation (GHT) of read-depth ratios between either paired test-control samples, or between test samples and a reference template constructed from reference samples, to call the localized CNVs, followed by use of a GISTIC-like algorithm to identify recurrent CNVs and circular binary segmentation (CBS) to reveal large extended CNVs. To evaluate the utility of CNVs called from AluScan data, the AluScans from 23 non-cancer and 38 cancer genomes were analyzed in this study. The glioma samples analyzed yielded the familiar extended copy-number losses on chromosomes 1p and 9. Also, the recurrent somatic CNVs identified from liver cancer samples were similar to those reported for liver cancer WGS with respect to a striking enrichment of copy-number gains in chromosomes 1q and 8q. When localized or recurrent CNV-features capable of distinguishing between liver and non-liver cancer samples were selected by correlation-based machine learning, a highly accurate separation of the liver and non-liver cancer classes was attained. The results obtained from non-cancer and cancerous tissues indicated that the AluScanCNV package can be employed to call localized, recurrent and extended CNVs from AluScan sequences. Moreover, both the localized and recurrent CNVs identified by this method could be subjected to machine-learning selection to yield distinguishing CNV-features that were capable of separating between liver cancers and other types of cancers. Since the method is applicable to any human DNA sample with or without the availability of a paired control, it can also be employed to analyze the constitutional CNVs of individuals.
    Journal of Clinical Bioinformatics 12/2014; 4(1):15. DOI:10.1186/s13336-014-0015-z
  • W Wt Lam · R Fielding · P Butow · B J Cowling · M Chan · A Or · A Kwong · D Suen ·

    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 12/2014; 20 Suppl 7:24-7. · 0.87 Impact Factor

Publication Stats

830 Citations
540.92 Total Impact Points


  • 2008-2015
    • Hong Kong Sanatorium & Hospital
      Hong Kong, Hong Kong
    • Stanford Medicine
      • Department of Surgery
      Stanford, California, United States
  • 2007-2015
    • The University of Hong Kong
      • Department of Surgery
      Hong Kong, Hong Kong
  • 2014
    • University of Ottawa
      Ottawa, Ontario, Canada
  • 2007-2014
    • Queen Mary Hospital
      Hong Kong, Hong Kong
  • 2013
    • University of Otago
      Taieri, Otago, New Zealand
  • 2007-2013
    • Stanford University
      • • Department of Surgery
      • • Department of Medicine
      • • Department of Radiology
      Palo Alto, California, United States
  • 2012
    • University of Cambridge
      • Department of Public Health and Primary Care
      Cambridge, England, United Kingdom
  • 2011
    • Hong Kong Hospital Authority
      Hong Kong, Hong Kong