Tamer Hifnawy

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.

Acute respiratory tract infections among Hajj medical mission personnel, Saudi Arabia

Summary Objectives To estimate the prevalence of acute respiratory tract infections (ARI) among 250 personnel serving in a Hajj medical mission, Al-Hada and Taif Armed Forces Hospitals, during the 2005 season and to determine the effectiveness of protective measures, including influenza vaccination, for these infections. Methods This was a nested case-control study. A questionnaire was distributed to the study cohort two weeks after the Hajj period and was self-administered by all recruited subjects. In addition, the medical records of study subjects were reviewed at Al-Hada Hospital for the same period in order to document ARI. Results The attack rate for ARI among study subjects during Hajj season or within two weeks of returning was 25.6% (64/250). Logistic regression analysis of factors related to acquiring ARI revealed that contact with pilgrims imposed an extremely high risk of infection (adjusted OR 13.2, 95% CI 1.5–117.6). Moreover, non-use of alcohol-based hand disinfection carried a more than 8-fold risk of acquiring ARI compared to those who always used alcohol for hand disinfection (adjusted OR 8.4, 95% CI 2.2–32.2). Smoking was also a predictor of ARI in our cohort and influenza vaccination was associated with a 30% reduction in ARI compared to unvaccinated subjects, although this finding was not statistically significant. Unexpectedly, the logistic regression model showed that Saudi nationals were three times more likely to acquire ARI than non-Saudis (adjusted OR 3.1, 95% CI 1.2–8.4). Conclusions The common practice among pilgrims and medical personnel of using surgical facemasks to protect themselves against ARI should be discontinued and regular use of alcohol-based hand scrubs should be more vigorously encouraged. Further research is needed to evaluate the protective value of N95 facemasks against ARI during the Hajj period.

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.

Collection, storage and use of blood samples for future research: views of Egyptian patients expressed in a cross-sectional survey

Objective To determine the attitudes of Egyptian patients regarding their participation in research and with the collection, storage and future use of blood samples for research purposes. Design Cross-sectional survey. Study population Adult Egyptian patients (n=600) at rural and urban hospitals and clinics. Results Less than half of the study population (44.3%) felt that informed consent forms should provide research participants the option to have their blood samples stored for future research. Of these participants, 39.9% thought that consent forms should include the option that future research be restricted to the illness being studied. A slight majority (66.2%) would donate their samples for future genetic research. Respondents were more favourable towards having their blood samples exported to other Arab countries (62.0%) compared with countries in Europe (41.8%, p<0.001) and to the USA (37.2%, p<0.001). Conclusions This study shows that many individuals do not favour the donation of a blood sample for future research. Of those who do approve of such future research, many favour a consent model that includes an option restricting the future research to the illness being studied. Also, many Egyptians were hesitant to have their blood samples donated for genetic research or exported out of the Arab region to the USA and European countries. Further qualitative research should be performed to determine the underlying reasons for many of our results.

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.

Genetic polymorphisms in NQO1 and SOD2: Interactions with smoking, schistosoma infection, and bladder cancer risk in Egypt

BACKGROUND Bladder cancer is the most prevalent form of cancer in men among Egyptians, for whom tobacco smoke exposure and Schistosoma haematobium (SH) infection are the major risk factors. We hypothesized that functional polymorphisms in NAD(P)H quinone oxidoreductase 1 (NQO1) and superoxide dismutase 2 (SOD2), modulators of the effects of reactive oxidative species, can influence an individuals susceptibility to these carcinogenic exposures and hence the risk of bladder cancer. METHODS We assessed the effects of potential interactions between functional polymorphisms in the NQO1 and SOD2 genes and exposure to smoking and SH infection on bladder cancer risk among 902 cases and 804 population-based controls in Egypt. We used unconditional logistic regression to estimate the odds ratios (OR) and confidence intervals (CI) 95%. RESULTS Water pipe and cigarette smoking were more strongly associated with cancer risk among individuals with the TT genotype for SOD2 (OR [CI 95%] = 4.41 [1.86-10.42]) as compared with those with the CC genotype (OR [CI 95%] = 2.26 [0.97-6.74]). Conversely, the risk associated with SH infection was higher among the latter (OR [CI 95%] = 3.59 [2.21-5.84]) than among the former (OR [CI 95%] = 1.86 [1.33-2.60]). Polymorphisms in NQO1 genotype showed a similar pattern, but to a much lesser extent. The highest odds for having bladder cancer following SH infection were observed among individuals with the CC genotypes for both NQO1 and SOD2 (OR [CI 95%] = 4.41 [2.32-8.38]). CONCLUSION Our findings suggest that genetic polymorphisms in NQO1 and SOD2 play important roles in the etiology of bladder cancer by modulating the effects of known contributing factors such as smoking and SH infection.

Associations differ by sex for catechol-O-methyltransferase genotypes and bladder cancer risk in South Egypt.

OBJECTIVES To examine associations between urinary bladder cancer risk and polymorphisms of the gene encoding the catechol estrogen-metabolizing enzyme, catechol-O-methyltransferase (COMT), among Egyptian women and men. MATERIALS AND METHODS We used questionnaire and genotype data from a case-control study in Egypt. This analysis focused on South Egypt cases with confirmed urothelial (UC) or squamous cell (SCC) carcinoma of the bladder, and controls frequency-matched on sex, 5-year age-group, and residence governorate. Real-time PCR on blood specimen DNA was used to determine COMT genotypes encoding for Val/Val, Val/Met, and Met/Met, the enzyme forms associated with high, intermediate, or low activity, respectively. RESULTS The study sample, which included 255 women and 666 men, consisted of 394 cases with histologically confirmed UC (225) or SCC (n = 169), and 527 controls. The odds of having either type of bladder cancer were lower among men with genotypes encoding Val/Met or Met/Met than among those with the genotype encoding Val/Val, even after adjustment for other factors, such as smoking and schistosomiasis history [adjusted odds ratio (AOR): 0.64; 95% confidence interval (CI): 0.43, 0.96]; however, the association was statistically significant for SCC (AOR 0.57; 95% CI: 0.34, 0.96) but marginal for UC (AOR: 0.64; 95% CI: 0.39, 1.02). No significant associations were detected between bladder cancer risk and COMT genotypes among postmenopausal women. CONCLUSIONS These findings suggest that even after controlling for established risk factors, the involvement of COMT genotypes in bladder cancer risk differs among men compared with women in South Egypt.

Radiographic assessment of impacted teeth and associated pathosis prevalence. Pattern of occurrence at different ages in Saudi male in Western Saudi Arabia

Objectives: To assess the prevalence of both impaction and associated pathosis in a Saudi population in Al-Madinah, Saudi Arabia based on digital panoramic radiographs. Methods: This study was carried out from December 2013 to February 2015. Panoramic radiographs of 359 male patients attending the Oral Diagnosis Clinics, Faculty of Dentistry, Taibah University, Al-Madinah, Saudi Arabia were reviewed. All images were evaluated to determine the prevalence and pattern of impacted third molars and canines, and associated pathosis. Results: Among 359 panoramic radiographs examined, 124 patients had impacted teeth. The impacted mandibular third molars were the most prevalent impacted teeth, 77.6% had class II pattern of impaction. Among the impacted maxillary canines, 75% were mesioangular and among 66 impacted maxillary third molars, 63.6% had class C. Our study showed that 5.8% of Saudi patients had 3 or more impacted teeth, 13.1% had 2 impacted teeth, and 15.6% had one impacted tooth. Associated pathosis was found in 18.2% among impacted maxillary third molars, and 31.5% among impacted mandibular third molars. The incidence of impaction decreases with age. Conclusion: The prevalence and pattern of impacted third molars among Saudis are almost similar to other racial populations. The number of missing wisdom increases with age. Although the percentage of pathosis associated with impaction was considerably low, it is essential to carry you regular oral examinations to preserve asymptomatic impacted teeth in good health.

Correlating dental caries with oral bacteria and the buffering capacity of saliva in children in Madinah, Saudi Arabia

Introduction: Caries is associated with high counts of mutans streptococci (MS), lactobacillus (LB), and a low saliva buffering capacity (BC). No study using odds ratios (OR) has correlated caries and these factors and no similar study has been done in Saudi Arabia before. Objectives: To determine: The prevalence of caries, the number of colony forming units (CFUs) of MS and LB, the saliva buffering capacity (BC) and the relationship between these factors. Materials and Methods: This was an analytical cross sectional study on children from Madinah. Caries was recorded using dmft/DMFT (decayed, missing, filled teeth). The scores for MS and LB and the BC of saliva was calculated using the Caries Risk Test (CRT)®. Results: A total of 316 students were examined; two-thirds (62%) were female and 25% were caries free. Saliva was collected from 235 participants and the majority had high MS and LB scores (66 and 71%, respectively) while 25% had a low saliva BC. The odds for those who had high LB and MS CFUs, were 9 and 4 times more at risk to developing dental caries and those with a low BC had significantly more caries (P = 0.03). The likelihood for those having severe caries and high counts of LB and MS was 25 (P < 0.01) and 6 (P = 0.042) times greater, respectively, compared to those with no or mild caries. Those with multiple risk factors were more likely to have caries compared to those with single or no risk factors present. Conclusions: The prevalence of caries was relatively high and many respondents had greater than 105 CFUs/ml of MS and LB. Almost all with a low BC had severe caries. There was a strong correlation between high MS, high LB, and low BC and the high prevalence of caries; hence the combination of these factors could be confidently used to predict caries in this population.