Displaying publications 1 - 20 of 30 in total

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  1. Iyngkaran N, Lee IL, Robinson MJ
    Scand. J. Infect. Dis., 1978;10(3):243-6.
    PMID: 362519
    A new metronidazole derivative, Tiberal (Ro-07-0207, Roche Laboratories), was evaluated in 22 children with Giardia lamblia infection. Seven patients received an oral dose of 1 g twice daily for one day; the remaining 15 patients received a single dose of 50 mg/kg. Parasitological cure was noted in all 22 patients. Significant side effects were observed only in those children who received the drug at the higher dosage regime. The present study also confirms the findings of other authors that a mucosal imprint method is more reliable than examination of stools, duodenal juice or jejunal biopsy material for the detection of G. lamblia infection.
  2. Noradilah SA, Anuar TS, Lee IL
    Helminthologia, 2022 Mar;59(1):55-63.
    PMID: 35601764 DOI: 10.2478/helm-2022-0004
    Trichuris trichiura is a soil-transmitted helminth prevalent in developing countries with poor, inadequate sanitation and unsafe water sources. In Malaysia, the prevalence of trichuriasis is relatively high among the aboriginal community due to poverty and poor sanitation. However, there are few studies to determine the seasonal variation on the prevalence and risk factors to acquire Trichuris trichiura infection in Malaysia. The present study found higher Trichuris trichiura infection during the dry season (63.6%; 138/217) in comparison to the wet season (55.5%; 142/256). Low household income, low education level and practice of open defecation were significant risk factors to acquire Trichuris trichiura infection during the wet season. Usage of untreated water supplies for daily activities was a risk factor to acquire trichuriasis during the dry season. This study highlighted that poverty and poor sanitation practices as well as drinking untreated water put the aborigines at high risk to acquire trichuriasis. Therefore, health education, improved sanitation and provision of treated water supply are recommended for the prevention and control of Trichuris trichiura infections in the aboriginal community.
  3. Teh KH, Lee IL, Hariffadzilah CH
    Med J Malaysia, 2024 Jul;79(4):393-396.
    PMID: 39086335
    INTRODUCTION: The Neonatal Resuscitation Programme (NRP) was first introduced in Malaysia in 1996 to train doctors and nurses working in paediatrics and obstetrics departments who are involved with the care of newborns soon after delivery. Prompt and effective neonatal resuscitation has been documented to reduce mortality and neonatal asphyxia. The programme has been revised every five years and is now in the 8th edition. NRP training was made into a key performance indicator (KPI) by the Ministry of Health in 2016 for all house officers to be trained in this programme during their 2-year posting and this is usually conducted during the paediatric posting. This study aims to evaluate the retention of their knowledge, skills and competency at 3, 6, and 9 months after the initial NRP training.

    MATERIALS AND METHODS: A total of 34 house officers were enrolled in the study on joining the paediatric unit of Hospital Kulim. They were given the "Textbook of NRP" to prepare for the theory paper that consisted of 30 multiplechoice questions (MCQs). Two to four weeks later they went through a day of training on the resuscitation of the newborn using low-fidelity simulation manikins. They were taught to recognise a newborn who needed resuscitation after delivery, prepared the equipment for resuscitation and learned the skills of resuscitation. The skills included the initial steps, bag valve mask ventilation, intubation, cardiac massage, umbilical vein cannulation and use of medications. They were also taught the performance of objective structured clinical examination (OSCE) A and B. They were evaluated at 3, 6, and 9 months after the completion of their training using the MCQs and the performance checklist in the NRP textbook.

    RESULTS: The results showed that there was a significant reduction in their knowledge retention as shown by their performance in multiple choice questions. Similarly, there was a significant loss of competency in their skills and competency in resuscitation using bag mask ventilation, intubation and performance of OSCE A and OSCE B. However, their performance at initial steps showed no significant reduction.

    CONCLUSION: In view of the observed deterioration a refresher course in NRP before transferring out to the districts is recommended to improve their overall performance.

  4. Lee IL, Tan TC, Tan PC, Nanthiney DR, Biraj MK, Surendra KM, et al.
    Parasitol Res, 2012 Apr;110(4):1553-62.
    PMID: 22076050 DOI: 10.1007/s00436-011-2665-0
    Blastocystis sp. is a common intestinal parasite. To date, there have been sporadic and scanty studies on Blastocystis sp. carried out in rural communities in Nepal. We surveyed the prevalence of Blastocystis sp. and its possible associated risk factors, and reported the predominant Blastocystis sp. subtype in two rural communities, Bolde Phediche and Bahunipati, in Nepal. Human faecal samples were collected from 241 participants, cultured using in vitro cultivation and examined for Blastocystis sp. The presence of Blastocystis sp. in faecal samples was further confirmed by polymerase chain reaction (PCR) and subsequently genotyped using subtype-specific sequence tagged site (STS) primers. There were 26.1% (63/241) of the participants that were infected by Blastocystis sp. We detected 84.1% (53/63) of Blastocystis sp. subtype 4 infections in these rural communities. The unusually high prevalence of Blastocystis sp. subtype 4 can be attributed to the rearing of family-owned animals in barns built close to their houses. Eighty one percent (51/63) of the Blastocystis sp. infected participants drank not boiled or unfiltered water. The present study revealed that Blastocystis sp. could pose a health concern to the communities and travellers to the hilly area in Nepal. Infection may be transmitted through human-to-human, zoonotic and waterborne transmissions. We provide recommendations to ensure good public health practices.
  5. Nguyen QT, Naguib RN, Abd Ghani MK, Bali RK, Lee IM
    Int J Electron Healthc, 2008;4(2):184-207.
    PMID: 18676343
    This paper presents an overview of the healthcare systems in Southeast Asia, with a focus on the healthcare informatics development and deployment in seven countries, namely, Singapore, Cambodia, Malaysia, Thailand, Laos, the Philippines and Vietnam. Brief geographic and demographic information is provided for each country, followed by a historical review of the national strategies for healthcare informatics development. An analysis of the state-of-the-art healthcare infrastructure is also given, along with a critical appraisal of national healthcare provisions.
  6. Van Kriekinge G, Sohn WY, Aljunid SM, Soon R, Yong CM, Chen J, et al.
    Asian Pac J Cancer Prev, 2018 Apr 25;19(4):933-940.
    PMID: 29693347
    Purpose: To comparatively evaluate the results of a 2-dose human papillomavirus (HPV) vaccination programme
    with the AS04-adjuvanted HPV16/18 vaccine (AS04-HPV-16/18v) or HPV-6/11/16/18 vaccine (4vHPVv), in addition
    to cervical cancer (CC) screening, in Malaysia. Methods: A lifetime Markov model replicating the natural history of
    HPV in 13-year-old girls was adapted to Malaysia to assess the impact of vaccination on pre-cancerous lesions, genital
    warts and CC cases, CC deaths, quality-adjusted life years (QALYs), and costs from the perspective of the Malaysian
    Ministry of Health. Vaccine effectiveness was based on efficacy and HPV type distribution. Both vaccines were assumed
    to have equal efficacy against vaccine-type HPV but differed for protection against non-vaccine types. Vaccine price
    parity was used and health and cost outcomes were discounted at 3%/annum. Sensitivity analyses tested the robustness
    of the results. Results: The model predicted that AS04-HPV-16/18v would result in 361 fewer CC cases and 115 fewer
    CC deaths than 4vHPVv, whereas 4vHPVv averted 4,241 cases of genital warts over the cohort’s lifetime. Discounted
    total costs showed savings of 18.50 million Malaysian Ringgits and 246 QALYs in favour of AS04-HPV-16/18v. In
    one-way sensitivity analyses, the discount rate was the most influential variable for costs and QALYs, but AS04-HPV-
    16/18v remained dominant throughout. A two-way sensitivity analysis to assess the longevity of cross-protection for both
    vaccines confirmed the base-case. Conclusions: In Malaysia, the use of AS04-HPV-16/18v, in addition to screening,
    was modelled to be dominant over 4vHPVv, with greater estimated CC benefits and lower costs.
  7. Liu JH, Choi SY, Lee IC, Leung AK, Lee M, Lin MH, et al.
    Sci Rep, 2023 Dec 04;13(1):21413.
    PMID: 38049436 DOI: 10.1038/s41598-023-47333-z
    While national parochialism is commonplace, individual differences explain more variance in it than cross-national differences. Global consciousness (GC), a multi-dimensional concept that includes identification with all humanity, cosmopolitan orientation, and global orientation, transcends national parochialism. Across six societies (N = 11,163), most notably the USA and China, individuals high in GC were more generous allocating funds to the other in a dictator game, cooperated more in a one-shot prisoner's dilemma, and differentiated less between the ingroup and outgroup on these actions. They gave more to the world and kept less for the self in a multi-level public goods dilemma. GC profiles showed 80% test-retest stability over 8 months. Implications of GC for cultural evolution in the face of trans-border problems are discussed.
  8. Attah AO, Ong KY, Sanggari A, Lee IL, Nik Him NAII, Ismail AH, et al.
    Trop Biomed, 2024 Sep 01;41(3):370-376.
    PMID: 39548792 DOI: 10.47665/tb.41.3.018
    Blastocystis is a ubiquitous waterborne parasite that has been implicated in some disease conditions including colorectal cancer and irritable bowel syndrome, and its surface coat characteristics have been associated with its pathogenicity. Although the morphology of Blastocystis isolates from human and animal sources have been studied, there is a paucity of data on the surface ultrastructure of Blastocystis isolated from water sources. Therefore, this study aimed to determine the occurrence and the ultrastructural surface of Blastocystis isolates from several water sources in Kedah and Penang, Malaysia. A total of 12 water samples were collected, namely, Pinang River and USM Harapan Lake all in Penang, whereas Lata Bayu Waterfall in Baling and UniSHAMS Lake, Kuala Ketil in Kedah. These were examined for Blastocystis by centrifugation and in vitro cultivation. Scanning electron microscopy (SEM) and light microscopy were employed to study the morphological characteristics and the surface ultrastructure of the parasite. Polymerase chain reaction (PCR) was carried out to obtain the subtypes (ST) of the positive Blastocystis isolates. The result revealed 25.0% (3/12) contamination with Blastocystis in which ST1, ST2, and an unknown ST (with a high similarity to ST1) were detected in water samples from the upstream, downstream, and midstream, respectively of Pinang River. Our study also revealed similarities in the sizes of the isolates from different river points, which were notably more diminutive compared to the sizes of the parasites observed in existing data from human and animal isolates. The surface characteristics showed a collection of single and dividing cells with smooth, folded surfaces enclosed in a film-like layer. Additionally, there were roundish, irregularly shaped cells with rough surfaces, and a woolly appearance. This study has added to our knowledge of the surface ultrastructure of Blastocystis and its possible contribution to the pathogenicity of the parasite.
  9. Lee J, Kwak YS, Kim YJ, Kim EJ, Park EJ, Shin Y, et al.
    Psychiatry Investig, 2018 Apr;15(4):336-343.
    PMID: 29669407 DOI: 10.30773/pi.2017.11.08.2
    "Comfort women" refers to young women and girls who were forced into sexual slavery by the Imperial Japanese military during World War II. They were abducted from their homes in countries under Imperial Japanese rule, mostly from Korea, and the rest from China, Philippines, Malaysia, Taiwan, Indonesia, the Netherlands, etc. "Comfort women" endured extreme trauma involving rape, sexual torture, physical abuse, starvation, threats of death, and witnessed many others being tortured and killed. This article reviews all the studies that have investigated the psychiatric or psychosocial sequelae of the survivors of the Japanese military sexual slavery. Most importantly, a recent study which conducted a psychiatric evaluation on the former "comfort women" currently alive in South Korea is introduced. The participants' unmarried rate was relatively high and their total fertility rate was relatively low. Majority of the participants reported having no education and being the low economic status. They showed high current and lifetime prevalence of posttraumatic disorder, major depressive disorder, somatic symptom disorder, social anxiety disorder, panic disorder, and alcohol use disorder. Participants showed high suicidality and majority of the participants still reported being ashamed of being former "comfort women" after all these years. This article high-lights the fact that the trauma has affected the mental health and social functioning of former "comfort women" throughout their lives, and even to the present day.
  10. Zhang RJ, Liu JH, Lee M, Lin MH, Xie T, Chen SX, et al.
    Philos Trans R Soc Lond B Biol Sci, 2024 Jan;379(1893):20220263.
    PMID: 37952613 DOI: 10.1098/rstb.2022.0263
    Global consciousness (GC), encompassing cosmopolitan orientation, global orientations (i.e. openness to multicultural experiences) and identification with all humanity, is a relatively stable individual difference that is strongly associated with pro-environmental attitudes and behaviours, less ingroup favouritism and prejudice, and greater pandemic prevention safety behaviours. Little is known about how it is socialized in everyday life. Using stratified samples from six societies, socializing institution factors correlating positively with GC were education, white collar work (and its higher income) and religiosity. However, GC also decreased with increasing age, contradicting a 'wisdom of elders' transmission of social learning, and not replicating typical findings that general prosociality increases with age. Longitudinal findings were that empathy-building, network-enhancing elements like getting married or welcoming a new infant, increased GC the most across a three-month interval. Instrumental gains like receiving a promotion (or getting a better job) also showed positive effects. Less intuitively, death of a close-other enhanced rather than reduced GC. Perhaps this was achieved through the ritualized management of meaning where a sense of the smallness of self is associated with growth of empathy for the human condition, as a more discontinuous or opportunistic form of culture-based learning. This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'.
  11. Choi YJ, Kim JY, Kang TU, Park HJ, Kim HC, Lee IY, et al.
    Trop Biomed, 2024 Jun 01;41(2):176-182.
    PMID: 39154270 DOI: 10.47665/tb.41.2.007
    The prevalence of tick-borne pathogens (TBP), Orientia tsutsugamushi, Rickettsia and Borrelia spp. in wild small animals, namely wild rodents, is now widely investigated. This study is to present the prevalence and distribution of O. tsutsugamushi, Rickettsia and Borrelia spp. in wild small animals and ticks collected from Gyeonggi and Gangwon provinces, Republic of Korea (ROK) in 2014. A total of 131 wild small animals, rodents and shrews, and 2,954 ticks were collected from Gyeonggi and Gangwon provinces from May to November 2014. The wild small animals (KR1-9) and ticks (K1-17) were grouped in accordance with capture dates and locations. Among the wild small animals, a total of 393 tissues and blood samples were extracted from six selected small animal series (KR1-3, KR6-8). Also, each date and location-grouped ticks were identified for its species and pooled according to the stage of development. Molecular identification for Rickettsia, Orientia, and Borrelia species was performed using polymerase chain reaction (PCR). To detect TBPs among wild small animals and ticks, primer sets targeting the 56 kDa protein encoding gene of Orientia spp., outer membrane protein B gene (OmpB) of Rickettsia spp., and 5S-23S intergenic spacer region (IGS) gene of Borrelia spp. were used. Of the 393 wild small animals' blood and tissue samples, 199 (50.6%) were positive for Orientia spp., 158 (40.2%) were positive for Borrelia spp., and 55 (14.0%) were positive for Rickettsia spp. Moreover, a total of 14 tick pools (n = 377) was positive for Rickettsia spp. (n=128, 34.0%) and Borrelia spp. (n=33, 8.8%). High prevalence of Orientia spp. and Rickettsia spp. in rodents and shrews were observed. This study presents significant insights by presenting data collected in 2014 that the prevalence of TBP was already high in mid 2010s. This study highlights the sustainable routine surveillance model for TBP.
  12. Muñoz-Moreno R, Martínez-Romero C, Blanco-Melo D, Forst CV, Nachbagauer R, Benitez AA, et al.
    Cell Rep, 2019 12 17;29(12):3997-4009.e5.
    PMID: 31851929 DOI: 10.1016/j.celrep.2019.11.070
    Influenza A viruses (IAVs) have a remarkable tropism in their ability to circulate in both mammalian and avian species. The IAV NS1 protein is a multifunctional virulence factor that inhibits the type I interferon host response through a myriad of mechanisms. How NS1 has evolved to enable this remarkable property across species and its specific impact in the overall replication, pathogenicity, and host preference remain unknown. Here we analyze the NS1 evolutionary landscape and host tropism using a barcoded library of recombinant IAVs. Results show a surprisingly great variety of NS1 phenotypes according to their ability to replicate in different hosts. The IAV NS1 genes appear to have taken diverse and random evolutionary pathways within their multiple phylogenetic lineages. In summary, the high evolutionary plasticity of this viral protein underscores the ability of IAVs to adapt to multiple hosts and aids in our understanding of its global prevalence.
  13. Zhang X, Goh GB, Chan WK, Wong GL, Fan JG, Seto WK, et al.
    Liver Int, 2020 11;40(11):2719-2731.
    PMID: 32799384 DOI: 10.1111/liv.14638
    BACKGROUND & AIMS: Lifestyle modification is the cornerstone for the management of non-alcoholic fatty liver disease (NAFLD). We aim to understand lifestyle habits of NAFLD patients, compare across Asian regions and identify area of deficiency.

    METHODS: In the multi-centre controlled attenuation parameter (CAP)-Asia study, we collected clinical data and lifestyle habit data of NAFLD patients from Singapore, mainland China, Hong Kong, Taiwan and Malaysia. Physical activity was assessed using the International Physical Activity Questionnaire.

    RESULTS: A total of 555 patients were included in the final analysis (mean age 54.5 ± 11.2 years, 54.1% men and median liver stiffness 6.7 kPa). More patients from mainland China (27.4%) and Taipei (25.0%) were smokers. Modest drinking was more common in Taiwan (25.0%) and Hong Kong (18.2%); only 1.3% had binge drinking. Majority of patients drank coffee (64.0%) and tea (80.2%), with varying amounts and durations in different regions. Soft drinks consumption was most common in Singapore (62.2%) and Malaysia (57.7%). Only 29.7% of patients met the Physical Activity Guidelines Recommendations, with no major differences across regions. Patients with liver stiffness <10 kPa were more likely to report any vigorous activity, and sitting time was an independent factor associated with high CAP. Tea and coffee consumption were independently associated with high CAP and liver stiffness, respectively.

    CONCLUSIONS: Despite some heterogeneity, unhealthy lifestyle and physical inactivity are common across Asian regions. Patients with liver stiffness <10 kPa were more likely to report any vigorous activity. Healthcare providers may use the comparative data to identify areas of deficiency.

  14. Leow YW, Chan WK, Goh GB, Wong VW, Fan JG, Kim YS, et al.
    J Viral Hepat, 2023 Apr;30(4):319-326.
    PMID: 36606597 DOI: 10.1111/jvh.13796
    We aimed to compare the severity of liver disease, metabolic profile and cardiovascular disease (CVD) risk of chronic hepatitis B (CHB) patients with and without hepatic steatosis and patients with non-alcoholic fatty liver disease (NAFLD). Patients with NAFLD and CHB were prospectively enrolled from 10 Asian centres. Fibroscan was performed for all patients and hepatic steatosis was defined based on controlled attenuation parameter >248 dB/m. CVD risk was assessed using the Framingham risk score. The data for 1080 patients were analysed (67% NAFLD, 33% CHB). A high proportion (59%) of CHB patients had hepatic steatosis. There was a significant stepwise increase in alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, controlled attenuation parameter and liver stiffness measurement, from CHB patients without hepatic steatosis to CHB patients with hepatic steatosis to NAFLD patients (p 
  15. Sun C, Goh GB, Chow WC, Chan WK, Wong GL, Seto WK, et al.
    Hepatobiliary Pancreat Dis Int, 2024 Jun;23(3):241-248.
    PMID: 37620227 DOI: 10.1016/j.hbpd.2023.08.004
    BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is associated with impaired renal function, and both diseases often occur alongside other metabolic disorders. However, the prevalence and risk factors for impaired renal function in patients with NAFLD remain unclear. The objective of this study was to identify the prevalence and risk factors for renal impairment in NAFLD patients.

    METHODS: All adults aged 18-70 years with ultrasound-diagnosed NAFLD and transient elastography examination from eight Asian centers were enrolled in this prospective study. Liver fibrosis and cirrhosis were assessed by FibroScan-aspartate aminotransferase (FAST), Agile 3+ and Agile 4 scores. Impaired renal function and chronic kidney disease (CKD) were defined by an estimated glomerular filtration rate (eGFR) with value of < 90 mL/min/1.73 m2 and < 60 mL/min/1.73 m2, respectively, as estimated by the CKD-Epidemiology Collaboration (CKD-EPI) equation.

    RESULTS: Among 529 included NAFLD patients, the prevalence rates of impaired renal function and CKD were 37.4% and 4.9%, respectively. In multivariate analysis, a moderate-high risk of advanced liver fibrosis and cirrhosis according to Agile 3+ and Agile 4 scores were independent risk factors for CKD (P< 0.05). Furthermore, increased fasting plasma glucose (FPG) and blood pressure were significantly associated with impaired renal function after controlling for the other components of metabolic syndrome (P< 0.05). Compared with patients with normoglycemia, those with prediabetes [FPG ≥ 5.6 mmol/L or hemoglobin A1c (HbA1c) ≥ 5.7%] were more likely to have impaired renal function (P< 0.05).

    CONCLUSIONS: Agile 3+ and Agile 4 are reliable for identifying NAFLD patients with high risk of CKD. Early glycemic control in the prediabetic stage might have a potential renoprotective role in these patients.

  16. Howson JMM, Zhao W, Barnes DR, Ho WK, Young R, Paul DS, et al.
    Nat Genet, 2017 Jul;49(7):1113-1119.
    PMID: 28530674 DOI: 10.1038/ng.3874
    Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide. Although 58 genomic regions have been associated with CAD thus far, most of the heritability is unexplained, indicating that additional susceptibility loci await identification. An efficient discovery strategy may be larger-scale evaluation of promising associations suggested by genome-wide association studies (GWAS). Hence, we genotyped 56,309 participants using a targeted gene array derived from earlier GWAS results and performed meta-analysis of results with 194,427 participants previously genotyped, totaling 88,192 CAD cases and 162,544 controls. We identified 25 new SNP-CAD associations (P < 5 × 10-8, in fixed-effects meta-analysis) from 15 genomic regions, including SNPs in or near genes involved in cellular adhesion, leukocyte migration and atherosclerosis (PECAM1, rs1867624), coagulation and inflammation (PROCR, rs867186 (p.Ser219Gly)) and vascular smooth muscle cell differentiation (LMOD1, rs2820315). Correlation of these regions with cell-type-specific gene expression and plasma protein levels sheds light on potential disease mechanisms.
  17. Ghoneim DH, Zhu J, Zheng W, Long J, Murff HJ, Ye F, et al.
    Cancer Epidemiol Biomarkers Prev, 2020 Dec;29(12):2735-2739.
    PMID: 32967863 DOI: 10.1158/1055-9965.EPI-20-0651
    BACKGROUND: Whether circulating polyunsaturated fatty acid (PUFA) levels are associated with pancreatic cancer risk is uncertain. Mendelian randomization (MR) represents a study design using genetic instruments to better characterize the relationship between exposure and outcome.

    METHODS: We utilized data from genome-wide association studies within the Pancreatic Cancer Cohort Consortium and Pancreatic Cancer Case-Control Consortium, involving approximately 9,269 cases and 12,530 controls of European descent, to evaluate associations between pancreatic cancer risk and genetically predicted plasma n-6 PUFA levels. Conventional MR analyses were performed using individual-level and summary-level data.

    RESULTS: Using genetic instruments, we did not find evidence of associations between genetically predicted plasma n-6 PUFA levels and pancreatic cancer risk [estimates per one SD increase in each PUFA-specific weighted genetic score using summary statistics: linoleic acid odds ratio (OR) = 1.00, 95% confidence interval (CI) = 0.98-1.02; arachidonic acid OR = 1.00, 95% CI = 0.99-1.01; and dihomo-gamma-linolenic acid OR = 0.95, 95% CI = 0.87-1.02]. The OR estimates remained virtually unchanged after adjustment for covariates, using individual-level data or summary statistics, or stratification by age and sex.

    CONCLUSIONS: Our results suggest that variations of genetically determined plasma n-6 PUFA levels are not associated with pancreatic cancer risk.

    IMPACT: These results suggest that modifying n-6 PUFA levels through food sources or supplementation may not influence risk of pancreatic cancer.

  18. Mocci E, Kundu P, Wheeler W, Arslan AA, Beane-Freeman LE, Bracci PM, et al.
    Cancer Res, 2021 Jun 01;81(11):3134-3143.
    PMID: 33574088 DOI: 10.1158/0008-5472.CAN-20-3267
    Germline variation and smoking are independently associated with pancreatic ductal adenocarcinoma (PDAC). We conducted genome-wide smoking interaction analysis of PDAC using genotype data from four previous genome-wide association studies in individuals of European ancestry (7,937 cases and 11,774 controls). Examination of expression quantitative trait loci data from the Genotype-Tissue Expression Project followed by colocalization analysis was conducted to determine whether there was support for common SNP(s) underlying the observed associations. Statistical tests were two sided and P < 5 × 10-8 was considered statistically significant. Genome-wide significant evidence of qualitative interaction was identified on chr2q21.3 in intron 5 of the transmembrane protein 163 (TMEM163) and upstream of the cyclin T2 (CCNT2). The most significant SNP using the Empirical Bayes method, in this region that included 45 significantly associated SNPs, was rs1818613 [per allele OR in never smokers 0.87, 95% confidence interval (CI), 0.82-0.93; former smokers 1.00, 95% CI, 0.91-1.07; current smokers 1.25, 95% CI 1.12-1.40, P interaction = 3.08 × 10-9). Examination of the Genotype-Tissue Expression Project data demonstrated an expression quantitative trait locus in this region for TMEM163 and CCNT2 in several tissue types. Colocalization analysis supported a shared SNP, rs842357, in high linkage disequilibrium with rs1818613 (r 2 = 0. 94) driving both the observed interaction and the expression quantitative trait loci signals. Future studies are needed to confirm and understand the differential biologic mechanisms by smoking status that contribute to our PDAC findings. SIGNIFICANCE: This large genome-wide interaction study identifies a susceptibility locus on 2q21.3 that significantly modified PDAC risk by smoking status, providing insight into smoking-associated PDAC, with implications for prevention.
  19. Yuan F, Hung RJ, Walsh N, Zhang H, Platz EA, Wheeler W, et al.
    Cancer Res, 2020 Sep 15;80(18):4004-4013.
    PMID: 32641412 DOI: 10.1158/0008-5472.CAN-20-0447
    Registry-based epidemiologic studies suggest associations between chronic inflammatory intestinal diseases and pancreatic ductal adenocarcinoma (PDAC). As genetic susceptibility contributes to a large proportion of chronic inflammatory intestinal diseases, we hypothesize that the genomic regions surrounding established genome-wide associated variants for these chronic inflammatory diseases are associated with PDAC. We examined the association between PDAC and genomic regions (±500 kb) surrounding established common susceptibility variants for ulcerative colitis, Crohn's disease, inflammatory bowel disease, celiac disease, chronic pancreatitis, and primary sclerosing cholangitis. We analyzed summary statistics from genome-wide association studies data for 8,384 cases and 11,955 controls of European descent from two large consortium studies using the summary data-based adaptive rank truncated product method to examine the overall association of combined genomic regions for each inflammatory disease group. Combined genomic susceptibility regions for ulcerative colitis, Crohn disease, inflammatory bowel disease, and chronic pancreatitis were associated with PDAC at P values < 0.05 (0.0040, 0.0057, 0.011, and 3.4 × 10-6, respectively). After excluding the 20 PDAC susceptibility regions (±500 kb) previously identified by GWAS, the genomic regions for ulcerative colitis, Crohn disease, and inflammatory bowel disease remained associated with PDAC (P = 0.0029, 0.0057, and 0.0098, respectively). Genomic regions for celiac disease (P = 0.22) and primary sclerosing cholangitis (P = 0.078) were not associated with PDAC. Our results support the hypothesis that genomic regions surrounding variants associated with inflammatory intestinal diseases, particularly, ulcerative colitis, Crohn disease, inflammatory bowel disease, and chronic pancreatitis are associated with PDAC. SIGNIFICANCE: The joint effects of common variants in genomic regions containing susceptibility loci for inflammatory bowel disease and chronic pancreatitis are associated with PDAC and may provide insights to understanding pancreatic cancer etiology.
  20. Tang H, Jiang L, Stolzenberg-Solomon RZ, Arslan AA, Beane Freeman LE, Bracci PM, et al.
    Cancer Epidemiol Biomarkers Prev, 2020 Sep;29(9):1784-1791.
    PMID: 32546605 DOI: 10.1158/1055-9965.EPI-20-0275
    BACKGROUND: Obesity and diabetes are major modifiable risk factors for pancreatic cancer. Interactions between genetic variants and diabetes/obesity have not previously been comprehensively investigated in pancreatic cancer at the genome-wide level.

    METHODS: We conducted a gene-environment interaction (GxE) analysis including 8,255 cases and 11,900 controls from four pancreatic cancer genome-wide association study (GWAS) datasets (Pancreatic Cancer Cohort Consortium I-III and Pancreatic Cancer Case Control Consortium). Obesity (body mass index ≥30 kg/m2) and diabetes (duration ≥3 years) were the environmental variables of interest. Approximately 870,000 SNPs (minor allele frequency ≥0.005, genotyped in at least one dataset) were analyzed. Case-control (CC), case-only (CO), and joint-effect test methods were used for SNP-level GxE analysis. As a complementary approach, gene-based GxE analysis was also performed. Age, sex, study site, and principal components accounting for population substructure were included as covariates. Meta-analysis was applied to combine individual GWAS summary statistics.

    RESULTS: No genome-wide significant interactions (departures from a log-additive odds model) with diabetes or obesity were detected at the SNP level by the CC or CO approaches. The joint-effect test detected numerous genome-wide significant GxE signals in the GWAS main effects top hit regions, but the significance diminished after adjusting for the GWAS top hits. In the gene-based analysis, a significant interaction of diabetes with variants in the FAM63A (family with sequence similarity 63 member A) gene (significance threshold P < 1.25 × 10-6) was observed in the meta-analysis (P GxE = 1.2 ×10-6, P Joint = 4.2 ×10-7).

    CONCLUSIONS: This analysis did not find significant GxE interactions at the SNP level but found one significant interaction with diabetes at the gene level. A larger sample size might unveil additional genetic factors via GxE scans.

    IMPACT: This study may contribute to discovering the mechanism of diabetes-associated pancreatic cancer.

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