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

Abstract

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 odds ratios (OR) and 95% confidence interval (CI) of the associations. Results Among men, cigarette smoking was associated with an increased risk of urothelial carcinoma (UC) (OR = 1.8, 95% CI = 1.4, 2.2), but not squamous cell carcinoma (SCC); smoking both waterpipes and cigarettes was associated with an even greater risk for UC (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 non-smoking men and women, to environmental tobacco smoke exposure was associated with an increased risk of UC. History of schistosomiasis was associated with increased risk of both UC (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 UC and SCC respectively) in men. Conclusions The results suggest that schistosomiasis and tobacco smoking increase the risk of both SCC and UC. Impact This study provides new evidence for associations between bladder cancer subtypes and schistosomiasis, and suggests that smoking both cigarettes and waterpipes increases the risk for SCC and UC in Egyptian men.

Pathological Pattern of Urinary Bladder Cancer: Data from a Single Egyptian Institute

“…In Egypt, over 25.5 million adults (51.2%) smoke at home 15 . The incidence of former and current smoker among patients included in this study was 62%, which clearly shows the higher risk of bladder cancer among Egyptian smokers and this is consistent with international published data that showed rate of smoking ranging between 69 and 77% 16,17 . A higher incidence of smoking reported among urinary bladder cancer patients (85%) was because of false definition since the researchers defined positive smoking as active smoking, second-hand smoking, and even cigarette industry workers 6 .…”

Urinary Bladder Cancer Risk Factors: A Lebanese Case-Control Study

“…Our study did not investigate schistosomiasis as a potential risk factor since this infection is very rare in Lebanon, and may be more relevant in countries like Egypt (Mostafa et al, 1999). Schistosomiasis is known to be associated with squamous cell carcinoma (SCC) (Zheng et al, 2012). The majority of our cases had papillary transitional cell carcinoma and absence of SCC.…”

Urinary Bladder Cancer Risk Factors in Egypt–Response

“…Dr. Behrens raises an interesting question concerning apparent inconsistencies between our results about tobacco association and the results of studies in Europe and the United States, especially as neither of the recent articles that he cites were available at the time we submitted our manuscript to this journal. As we noted in the Discussion section of our manuscript (1), "Worldwide, urothelial carcinoma is the predominant type of urinary bladder cancer (>90%) and cigarette smoking is a well-established risk factor," and we noted and referenced aspects of cigarette smoking dose and behavior that have been previously associated with increased risk. Dr Behrens correctly observes that our results from the study in Egypt are different from most previous work, and indeed we discussed this point in our manuscript.…”