Surapon Wiangnon

Epidemiology of cholangiocarcinoma: an update focusing on risk factors.

(Cancer Sci 2010; 101: 579–585)

The diverse molecular basis and hematological features of Hb H and AEBart's diseases in Northeast Thailand

We defined the molecular basis and correlated the hematological phenotypes with the globin genotypes in 52 patients with Hb H disease and 29 patients with AEBart’s disease of northeast Thailand. Among the former group, the most prevalent molecular defect was found to be the interaction of α-thalassemia 1 (SEA type) with the Hb Constant Spring (Hb CS; 35 of 52 patients), followed by the deletion of three α-globin genes with the SEA type α-thalassemia 1 and the 3.7- or 4.2-kb deletion of α-thalassemia 2 (14 of 52 patients) and the interaction of the SEA α-thalassemia 1 with the Hb Paksé which was found in the remaining 3 patients. Among the 29 patients of the latter group, in 18 disease was caused by interactions of Hb E heterozygotes with the SEA α-thalassemia 1 and Hb CS. Interaction of Hb E heterozygotes with a deletional form of Hb H disease was detected in 7 patients and the Hb Paksé AEBart’s disease was found in another 3 patients. A remaining patient with an unusually severe form of AEBart’s disease with a lower Hb E level and observable Hb H was associated with a hitherto undescribed condition, the interaction of Hb E heterozygote with α-thalassemia 1 and an α2 codon 30 (GAG) deletion. Hematological characterization of the patients demonstrated that although disease in most of them was associated with thalassemia intermedia phenotypes, it was apparent that association with the nondeletional form of α-thalassemia 2 produced a more severe phenotype than that of the deletional one. Therefore, α-globin gene analysis of Hb H and AEBart’s disease patients would be useful for predicting the clinical outcome and improving genetic counseling.

Molecular, hematological and clinical aspects of thalassemia major and thalassemia intermedia associated with Hb E-β-thalassemia in Northeast Thailand

Hb E-beta-thalassemia is the most common form of beta-thalassemia found in Thailand. The disease exhibits a varied clinical expression ranging from severe transfusion dependence to relatively mild thalassemia intermedia. We evaluated the effects of primary and secondary genetic factors in modulating the hematological and clinical presentation of 148 northeast Thai patients including 103 severe thalassemia major (TM) and 45 thalassemia intermedia (TI). Among 148 cases examined, eleven different mutations including two novel ones; (beta(33/34 (-G)) and beta(IVS2#815 C-T)) were identified in trans to the beta(E) gene in two TM cases. The other 9 known mutations included beta(41/42), beta(17), beta(IVS2#654), beta(-28), beta(71/72), beta(35), beta(IVS1#5), beta(IVS1#1) and beta(41). Except for the beta(-28) mutation which was found only in the TI group, others mutations were identified in both TM and TI. Co-inheritance of alpha-thalassemia as a phenotype modulating factor was not evident in this study, nor was the presence of the -158 (G)gamma-globin Xmn I polymorphism. Further analysis of the polymorphic (TG)n(CG)m repeats within the IVS2 of the two gamma-globin genes revealed no different proportions of the polymorphic patterns among TM and TI groups of patients either. Our data reveals that in the majority of these Hb E-beta-thalassemia patients, it is very hard to predict the clinical phenotype of the patients from the beta-globin mutations and these secondary genetic modifiers.

Functional Polymorphisms in the TERT Promoter Are Associated with Risk of Serous Epithelial Ovarian and Breast Cancers

Genetic variation at the TERT-CLPTM1L locus at 5p15.33 is associated with susceptibility to several cancers, including epithelial ovarian cancer (EOC). We have carried out fine-mapping of this region in EOC which implicates an association with a single nucleotide polymorphism (SNP) within the TERT promoter. We demonstrate that the minor alleles at rs2736109, and at an additional TERT promoter SNP, rs2736108, are associated with decreased breast cancer risk, and that the combination of both SNPs substantially reduces TERT promoter activity.

Risk Factors for Colon Cancer in Northeastern Thailand : Interaction of MTHFR Codon 677 and 1298 Genotypes with Environmental Factors

Background Polymorphisms in methylenetetrahydrofolate reductase (MTHFR), such as MTHFR C677T and A1298C, are associated with several cancers. This study aimed to evaluate the effects of MTHFR polymorphisms on colon cancer risk and possible interactions with environmental factors in a population from northeastern Thailand. Methods This hospital-based case–control study was conducted during 2002–2006; 130 colon cancer cases and 130 age- and sex-matched controls were enrolled. Information was collected and blood samples were obtained for assay of MTHFR C677T and A1298C polymorphisms by polymerase chain reaction with restriction fragment length polymorphism techniques. Associations between variables of interest and colon cancer were assessed using conditional logistic regression. Results Increased risk of colon cancer was associated with alcohol consumption and bowel habits. Alcohol drinkers who consumed ≤0.50 or >0.50 units of alcohol per day had elevated risks (ORadj = 3.5; 95% CI: 1.19–10.25 and ORadj = 1.71; 95% CI: 0.74–3.96, respectively). The risk was also higher in subjects with frequent constipation (11.69; 2.18–62.79) and occasional constipation (3.43; 1.72–6.82). An interaction was observed between the MTHFR C677T polymorphism and freshwater fish consumption on colon cancer risk (P value for interaction = 0.031). Interactions were observed between the MTHFR A1298C polymorphism and bowel habits, family history of cancer, alcohol consumption, and beef consumption on colon cancer risk (P-value for interaction = 0.0005, 0.007, 0.067, 0.003, respectively). Conclusions In a Thai population, colon cancer risk was associated with alcohol and beef consumption, bowel habits, and family history of cancer. Interactions between MTHFR polymorphisms and environmental factors were also observed.

Retrospective study on the combination of desferrioxamine and deferasirox for treatment of iron-overloaded thalassemic patients: first evidence of more than 2 years.

Some iron-overloaded patients have problems being treated with iron chelators. We therefore retrospectively studied 7 iron-overloaded thalassemic patients. Within the same week, patients received 20 to 30 mg/kg/d of oral deferasirox for 4 consecutive days, then a subcutaneous infusion of 20 to 40 mg/kg/d of desferrioxamine for 8 to 12 hours on the next 3 consecutive days. The median treatment duration was 25 months (range, 8 to 32). All of the patients showed a decrease in serum ferritin without any side effects. The protocol, combining deferasirox and desferrioxamine in sequence, was effective and safe: more cases should be studied.

The XRCC3 Thr241Met polymorphism and breast cancer risk: a case–control study in a Thai population

Abstract The X-ray repair cross-complementing group 3 gene (XRCC3) belongs to a family of genes responsible for repairing DNA double-strand breaks caused by normal metabolic processes and exposure to ionizing radiation. Polymorphisms in DNA repair genes may alter an individuals capacity to repair damaged DNA and may lead to genetic instability and contribute to malignant transformation. We examined the role of a polymorphism in the XRCC3 gene (rs861529; codon 241: threonine to methionine change) in determining breast cancer risk in Thai women. The study population consisted of 507 breast cancer cases and 425 healthy women. The polymorphism was analysed by fluorescence-based melting curve analysis. The XRCC3 241Met allele was found to be uncommon in the Thai population (frequency 0.07 among cases and 0.05 among controls). Odds ratios (OR) adjusted for age, body mass index, age at menarche, family history of breast cancer, menopausal status, reproduction parameters, use of contraceptives, tobacco smoking, involuntary tobacco smoking, alcohol drinking, and education were calculated for the entire population as well as for pre- and postmenopausal women. There was a significant association between 241Met carrier status and breast cancer risk (OR 1.58, 95% confidence interval (CI) 1.02–2.44). Among postmenopausal women, a slightly higher OR (1.82, 95% CI 0.95–3.51) was found than among premenopausal women (OR 1.48, 95% CI 0.82–2.69). Our findings suggest that the XRCC3 Thr241Met polymorphism is likely to play a modifying role in the individual susceptibility to breast cancer among Thai women as already shown for women of European ancestry.

Survival of Cholangiocarcinoma Patients in Northeastern Thailand after Supportive Treatment

BACKGROUND Cholangiocarcinoma (CCA) is a very common cancer in Northeastern Thailand. Most CCA patients see a physician at a late stage when curative surgery is not possible. After diagnosis, they generally are treated by partial surgery/percutaneous drainage, chemotherapy and supportive treatment. OBJECTIVE This study aimed to assess the survival rates of CCA patients after supportive treatment. METHODS A retrospective cohort design was applied in this study. Data for 746 CCA patients were extracted from the hospital-based cancer registry of Srinagarind Hospital, Khon Kaen University. The patients were diagnosed (at least by ultrasonography) between 1 January, 2009 and 31 December, 2009 and then followed up for current status until 30 June, 2011. The cumulative survival rate was calculated by the Kaplan-Meier method, and independent prognostic factors were investigated using Cox regression. RESULTS The total follow-up time was 5,878 person-months, and the total number of deaths was 637. The mortality rate was therefore 10.8 per 100 person-year (95%CI : 10.1-11.7). The cumulative 3, 6, 9, 12 and 24 month survival rates were 59%, 39%, 31%, 24% and 14%, respectively. The median survival time after supportive treatment was 4 months. After adjusting for gender, age, stage, distant metastasis, histological grading and treatment, stage was a significant predictor of survival of CCA patients. Those in stage III and stage IV had a 6.78 fold higher mortality than the stage I and stage II cases (95% CI : 1.6-28.7). CONCLUSION It is very important to encourage patients to see health personnel at an early stage.

Development of severe anemia during fever episodes in patients with hemoglobin E trait and hemoglobin H disease combinations.

Globin chain imbalance and tissue hypoxia are important determinants of the clinical severity of thalassemias. Phenotypic expression may be further modified by interactions between α- and β-thalassemia defects. We retrospectively and prospectively studied the clinical and hematologic features in children and adults with hemoglobin (Hb) E trait/Hb H disease (SEA/Paksé) (seven cases) and Hb E trait/Hb H disease (SEA/Constant Spring) (29 cases) and found that they had similar presentations. The severity of these two intermediate thalassemic manifestations ranged from very mild to severe. Severe anemia developed in accordance with very high fever, whereupon the range of Hb and hematocrit (Hct) levels declined to 5.2–5.8 g/dL and 13%–19%, respectively. In one case, during a hemoconcentrated state as occurs in dengue hemorrhagic fever, the Hb and Hct were 10 g/dL and 31%; the latter rose to 35% after fluid therapy. In some patients, the range of Hb and Hct levels was constantly low (4.3–5.8 g/dL and 15%–19%, respectively). (If dengue hemorrhagic fever is misdiagnosed, a fatal outcome may occur for thalassemic patients.) After a hemodiluted condition as in acute post-streptococcal glomerulonephritis, the respective Hb and Hct were 5.4 g/dL and 19%. These observations suggest that the instability of Hb E, especially during fever, may play an important role in the clinical manifestations of Hb E trait/Hb H disease with Hb Paksé and with Hb Constant Spring.

Prediction of idiopathic respiratory distress syndrome by the stable microbubble test on gastric aspirate

We evaluated the usefulness and accuracy of the stable microbubble test (SMT) performed on gastric aspirates of neonates to predict idiopathic respiratory distress syndrome (IRDS) and compared the results with those of the shake test, using the clinical characteristics of IRDS as the gold standard for the diagnosis of IRDS. One hundred forty paired samples of gastric aspirates, obtained within 1 hour of delivery from neonates with gestational ages between 27 and 42 weeks (mean, 36.6 ± 3.5 weeks) and birth weights between 800 and 4,090 grams (mean 2,571 ± 826 grams) were evaluated.