Sameera Ezzat

Detection of Hepatocellular Carcinoma Using Glycomic Analysis

Purpose: Hepatocellular carcinoma (HCC) represents an increasing health problem in the United States. Serum α-fetoprotein, the currently used clinical marker, is elevated in only ∼60% of HCC patients; therefore, the identification of additional markers is expected to have significant public health impact. The objective of our study was to quantitatively assess N-glycans originating from serum glycoproteins as alternative markers for the detection of HCC. Experimental Design: We used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for quantitative comparison of 83 N-glycans in serum samples of 202 participants (73 HCC cases, 77 age- and gender-matched cancer-free controls, and 52 patients with chronic liver disease). N-glycans were enzymatically released from serum glycoproteins and permethylated before mass spectrometric quantification. Results: The abundance of 57 N-glycans was significantly altered in HCC patients compared with controls. The sensitivity of six individual glycans evaluated for separation of HCC cases from population controls ranged from 73% to 90%, and the specificity ranged from 36% to 91%. A combination of three selected N-glycans was sufficient to classify HCC with 90% sensitivity and 89% specificity in an independent validation set of patients with chronic liver disease. The three N-glycans remained associated with HCC after adjustment for chronic viral infection and other known covariates, whereas the other glycans increased significantly at earlier stages of the progression of chronic viral infection to HCC. Conclusion: A set of three identified N-glycans is sufficient for the detection of HCC with 90% prediction accuracy in a population with high rates of hepatitis C viral infection. Further evaluation of a wider clinical utility of these candidate markers is warranted.

The Childhood Leukemia International Consortium

BACKGROUND Acute leukemia is the most common cancer in children under 15 years of age; 80% are acute lymphoblastic leukemia (ALL) and 17% are acute myeloid leukemia (AML). Childhood leukemia shows further diversity based on cytogenetic and molecular characteristics, which may relate to distinct etiologies. Case-control studies conducted worldwide, particularly of ALL, have collected a wealth of data on potential risk factors and in some studies, biospecimens. There is growing evidence for the role of infectious/immunologic factors, fetal growth, and several environmental factors in the etiology of childhood ALL. The risk of childhood leukemia, like other complex diseases, is likely to be influenced both by independent and interactive effects of genes and environmental exposures. While some studies have analyzed the role of genetic variants, few have been sufficiently powered to investigate gene-environment interactions. OBJECTIVES The Childhood Leukemia International Consortium (CLIC) was established in 2007 to promote investigations of rarer exposures, gene-environment interactions and subtype-specific associations through the pooling of data from independent studies. METHODS By September 2012, CLIC included 22 studies (recruitment period: 1962-present) from 12 countries, totaling approximately 31000 cases and 50000 controls. Of these, 19 case-control studies have collected detailed epidemiologic data, and DNA samples have been collected from children and child-parent trios in 15 and 13 of these studies, respectively. Two registry-based studies and one study comprising hospital records routinely obtained at birth and/or diagnosis have limited interview data or biospecimens. CONCLUSIONS CLIC provides a unique opportunity to fill gaps in knowledge about the role of environmental and genetic risk factors, critical windows of exposure, the effects of gene-environment interactions and associations among specific leukemia subtypes in different ethnic groups.

Urinary Bladder Cancer Risk Factors in Egypt: A Multicenter Case–Control Study

Background: We investigated associations between tobacco exposure, history of schistosomiasis, and bladder cancer risk in Egypt. Methods: We analyzed data from a case–control study (1,886 newly diagnosed and histologically confirmed cases and 2,716 age-, gender-, and residence-matched, population-based controls). Using logistic regression, we estimated the covariate-adjusted ORs and 95% confidence interval (CI) of the associations. Results: Among men, cigarette smoking was associated with an increased risk of urothelial carcinoma (OR = 1.8; 95% CI, 1.4–2.2) but not squamous cell carcinoma (SCC); smoking both water pipes and cigarettes was associated with an even greater risk for urothelial carcinoma (OR = 2.9; 95% CI, 2.1–3.9) and a statistically significant risk for SCC (OR = 1.8; 95% CI, 1.2–2.6). Among nonsmoking men and women, environmental tobacco smoke exposure was associated with an increased risk of urothelial carcinoma. History of schistosomiasis was associated with increased risk of both urothelial carcinoma (OR = 1.9; 95% CI, 1.2–2.9) and SCC (OR = 1.9; 95% CI, 1.2–3.0) in women and to a lesser extent (OR = 1.4; 95% CI, 1.2–1.7 and OR = 1.4; 95% CI, 1.1–1.7, for urothelial carcinoma and SCC, respectively) in men. Conclusions: The results suggest that schistosomiasis and tobacco smoking increase the risk of both SCC and urothelial carcinoma. Impact: This study provides new evidence for associations between bladder cancer subtypes and schistosomiasis and suggests that smoking both cigarettes and water pipes increases the risk for SCC and urothelial carcinoma in Egyptian men. Cancer Epidemiol Biomarkers Prev; 21(3); 537–46. ©2011 AACR.

Characterisation of aflatoxin and deoxynivalenol exposure among pregnant Egyptian women

Mycotoxins such as the aflatoxins and deoxynivalenol (DON) are frequent contaminants of food. Aflatoxin B1 (AFB1) and DON affect the immune system and restrict growth; additionally AFB1 is carcinogenic. To date there are limited descriptive biomarker data concerning maternal exposures during pregnancy, and none on co-exposures to these mycotoxins. This survey was a cross-sectional assessment providing descriptive data on the concentrations of serum aflatoxin–albumin (AF-alb), urinary aflatoxin M1 (AFM1), and urinary DON for 98 pregnant women from Egypt, in relation to diet and socioeconomic status, during the third trimester. AF-alb was detected in 34 of 98 (35%) samples, geometric mean (GM) of positives = 4.9 pg AF-lys mg−1 albumin (95% confidence interval (CI) = 4.1–5.8 pg mg−1), and AFM1 in 44 of 93 (48%) samples, GM of positives = 19.7 pg mg−1 creatinine (95%CI = 14.8–26.3 pg mg−1). AF-alb and AFM1 levels were positively correlated (R = 0.276, p = 0.007). DON was detected in 63 of 93 (68%), GM of positives = 2.8 ng mg−1 (95%CI = 2.1–3.6 ng mg−1). Aflatoxin and DON biomarkers were observed in 41% of the subjects concurrently. The frequency and level of these biomarkers in Egyptian women were modest compared with known high-risk countries. However, this study represents the first biomarker survey to report on the occurrence of DON biomarkers in an African population, in addition to the co-occurrence of these two potent mycotoxins. This combined exposure may be of particular concern during pregnancy given the potential of toxin transfer to the foetus.

Maternal supplementation with folic acid and other vitamins and risk of leukemia in offspring: a Childhood Leukemia International Consortium study.

Background: Maternal prenatal supplementation with folic acid and other vitamins has been inconsistently associated with a reduced risk of childhood acute lymphoblastic leukemia (ALL). Little is known regarding the association with acute myeloid leukemia (AML), a rarer subtype. Methods: We obtained original data on prenatal use of folic acid and vitamins from 12 case-control studies participating in the Childhood Leukemia International Consortium (enrollment period: 1980–2012), including 6,963 cases of ALL, 585 cases of AML, and 11,635 controls. Logistic regression was used to estimate pooled odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for child’s age, sex, ethnicity, parental education, and study center. Results: Maternal supplements taken any time before conception or during pregnancy were associated with a reduced risk of childhood ALL; odds ratios were 0.85 (95% CI = 0.78–0.92) for vitamin use and 0.80 (0.71–0.89) for folic acid use. The reduced risk was more pronounced in children whose parents’ education was below the highest category. The analyses for AML led to somewhat unstable estimates; ORs were 0.92 (0.75–1.14) and 0.68 (0.48–0.96) for prenatal vitamins and folic acid, respectively. There was no strong evidence that risks of either types of leukemia varied by period of supplementation (preconception, pregnancy, or trimester). Conclusions: Our results, based on the largest number of childhood leukemia cases to date, suggest that maternal prenatal use of vitamins and folic acid reduces the risk of both ALL and AML and that the observed association with ALL varied by parental education, a surrogate for lifestyle and sociodemographic characteristics.

Estrogen exposure and bladder cancer risk in Egyptian women

OBJECTIVE To examine associations between reproductive history and urinary bladder cancer in Egyptian women. METHODS We used questionnaire data from an ongoing, multicenter case-control study in Egypt. Controls were matched on age and residence area. This analysis focused on female cases with confirmed urothelial (UC) and squamous cell (SCC) carcinoma of the bladder. RESULTS We recruited 779 women (540 controls, 239 cases; >98.0% nonsmokers). Younger age at menopause (<45 y) and older age at first pregnancy (>18 y) were factors significantly associated with increased risk of bladder cancer, even after adjusting for schistosomiasis history and other covariates in the multivariable logistic model; adjusted odds ratio and 95% confidence intervals were 1.98 (1.41, 2.77) and 6.26 (3.46, 11.34), respectively. On the other hand, multiple pregnancies or use of oral contraceptives were associated with decreased odds of having bladder cancer. Similar associations were observed with UC and SCC when analyzed separately; however, the magnitude of association with SCC was lower than with UC. CONCLUSION Our data suggest that early estrogen exposure, or the relative lack of it, plays a role in urinary bladder carcinoma development among Egyptian women.

Pilot survey of aflatoxin–albumin adducts in sera from Egypt

Aflatoxins are potent liver carcinogens that frequently contaminate cereals in developing countries. Aflatoxin exposure has been predicted in Egypt but, to date, no studies have measured the level of aflatoxin–albumin (AF–alb) adducts as a validated biomarker to assess exposure. In this pilot survey, a limited number of sera samples, available from a hepatocellular carcinoma (HCC) case-control study in Egypt, were analysed. AF–alb was detected in 24/24 samples from HCC-negative individuals (geometric mean 9.0 pg mg−1; range 3.5–25.8pg mg−1), while 7/22 samples from HCC-positive cases had detectable AF–alb (geometric mean 2.6 pg mg−1; range: non-detectable–32.8 pg mg−1). These AF–alb data do not represent a case-control comparison due to inherent difficulties in comparing markers of dietary intake between controls and patients with disease. Although these data are limited, the potential health consequences of aflatoxin exposure in this region merit further investigation.

GSTM1, GSTT1 Null Variants, and GPX1 Single Nucleotide Polymorphism Are Not Associated with Bladder Cancer Risk in Egypt

Background: Bladder cancer is the most common male malignancy in Egypt, consists predominantly of urothelial cell carcinoma (UCC) and squamous cell carcinoma (SCC), and disparities in incidence exist between men and women regardless of geographic region. Tobacco smoke exposure and Schistosoma haematobium (SH) infection and the presence of GSTM1, GSTT1, and GPX1 genotypes, as modulators of the carcinogenic effect of reactive oxidative species, were hypothesized to modify bladder cancer risk and possibly explain these gender differences. Methods: We evaluated the association between bladder cancer risk and functional polymorphisms in the GSTM1, GSTT1, and GPX1 genes in 625 cases and 626 matched population-based controls in Egypt and assessed for potential interactions between these candidate genes and environmental exposures, such as smoking and SH infection. We analyzed the risk for developing UCC and SCC separately. Results: None of these functional polymorphisms were significantly associated with bladder cancer risk. There were no significant interactions between genotypes and smoking or SH infection in this population, nor was any difference detected in genotypic risk between men and women. Conclusions: Our findings suggest that common genetic variations in GSTM1, GSTT1, and GPX1 are not associated with bladder cancer risk overall and that well-known environmental risk factors, such as smoking and SH infection, do not interact with these genes to modulate the risk. Impact: Our data indicate that common genetic variations in GSTM1, GSTT1, and GPX1 were not associated with bladder cancer risk. Cancer Epidemiol Biomarkers Prev; 20(7); 1552–4. ©2011 AACR.

Caesarean delivery and risk of childhood leukaemia: a pooled analysis from the Childhood Leukemia International Consortium (CLIC)

BACKGROUND Results from case-control studies have shown an increased risk of acute lymphoblastic leukaemia (ALL) in young children born by caesarean delivery, and prelabour caesarean delivery in particular; however, an association of method of delivery with childhood leukaemia subtypes has yet to be established. We therefore did a pooled analysis of data to investigate the association between childhood leukaemia and caesarean delivery. METHODS We pooled data from 13 case-control studies from the Childhood Leukemia International Consortium done in nine countries (Canada, Costa Rica, Egypt, France, Germany, Greece, Italy, New Zealand, and the USA) for births from 1970-2013. We analysed caesarean delivery overall and by indications that probably resulted in prelabour caesarean delivery or emergency caesarean delivery. We used multivariable logistic regression models, adjusted for childs birthweight, sex, age, ethnic origin, parental education, maternal age, and study, to estimate odds ratios (ORs) and 95% CIs for the risk of ALL and acute myeloid leukaemia (AML) in children aged 0-14 years at diagnosis. FINDINGS The studies provided data for 8780 ALL cases, 1332 AML cases, and 23 459 controls, of which the birth delivery method was known for 8655 (99%) ALL cases, 1292 (97%) AML cases, and 23 351 (>99%) controls. Indications for caesarean delivery were available in four studies (there were caesarean deliveries for 1061 of 4313 ALL cases, 138 of 664 AML cases, and 1401 of 5884 controls). The OR for all indications of caesarean delivery and ALL was 1·06 (95% CI 0·99-1·13), and was significant for prelabour caesarean delivery and ALL (1·23 [1·04-1·47]; p=0·018). Emergency caesarean delivery was not associated with ALL (OR 1·02 [95% CI 0·81-1·30]). AML was not associated with caesarean delivery (all indications OR 0·99 [95% CI 0·84-1·17]; prelabour caesarean delivery 0·83 [0·54-1·26]; and emergency caesarean delivery 1·05 [0·63-1·77]). INTERPRETATION Our results suggest an increased risk of childhood ALL after prelabour caesarean delivery. If this association is causal, maladaptive immune activation due to an absence of stress response before birth in children born by prelabour caesarean delivery could be considered as a potential mechanism. FUNDING National Cancer Institute.

Immunohistochemical Detection of Hepatitis C Virus (Genotype 4) in B-cell NHL in an Egyptian Population: Correlation With Serum HCV-RNA

Background and AimRetrospective evaluation of hepatitis C virus (HCV) prevalence in lymphoma tissues has important applications in clarifying the contribution of viral factors to the pathogenesis. Trials for detection of HCV at the cellular level in lymphoma tissues are, so far, minimal with unsatisfactory results. We aimed to study the detection and localization of HCV in the tissues of B-cell non-Hodgkin lymphoma (NHL) patients. DesignWe performed immunohistochemistry to detect the HCV nonstructural 3 protein in paraffin-embedded tissue specimens of B-cell NHL patients, in 39 serum HCV-RNA positive samples and 35 serum HCV-RNA negative samples as controls. The serum analysis was carried out for HCV antibodies using enzyme-linked immunoassay and for HCV-RNA using reverse transcription-polymerase chain reaction. Reverse transcription-polymerase chain reaction was used to detect the HCV-RNA in tissues in immunohistochemically positive cases. We correlated the results with the clinicopathologic characteristics of the patients. ResultsA diffuse cytoplasmic immunohistochemical staining for HCV in the lymphoid cells was detected in 8 of 39 serum positive cases (20.5%), all of which were genotype 4, which is the most prevalent HCV genotype in Egypt. Only 2 out of 35 serum negative control samples showed positive staining and in 1 of them HCV-RNA was detected in tissue. No significant correlation was detected between HCV positive cases and the clinicopathologic features of the patients. ConclusionsImmunohistochemical detection of HCV proteins in lymphoma tissues supports a potential role of viral replication in lymphomagenesis. The low number of cases showing expression of viral proteins may represent a low viral load in lymphoid tissue and/or restriction of HCV protein expression to certain subtypes of B-cell NHL. Immunohistochemistry can be used as a complementary tool for specific HCV detection in the paraffin-embedded material of lymphoma tissues not suitable for RNA analysis.