RESUMO
A case-control study was conducted to assess magnitude of the risk of urinary schistosomiasis and other possible risk factors for squamous and transitional cell types of bladder cancer [BC] in Egypt. Cases included 301 patients who were recruited from National Institute of Cancer at Cairo presenting with an early stage of BC; 148 with squamous cell carcinoma [SCC] and 153 patients with transitional cell carcinoma [TCC]. A definitive diagnosis of BC and its cell type was based on histopathological examination of biopsy. Controls included 154 subjects admitted for surgery other than cancer. Urinalysis and ultrasound examinations were used to exclude controls with evidence of lesions suspicious of BC. Both cases and controls were interviewed using a structured risk-assessment questionnaire. The collected data included age, gender, diagnosis of urinary schistosomiasis, and urinary stones, smoking status, exposure to pesticides, and petrochemical products. Resuits of the bivariate analysis, showed increased significant risks for both types of BC with age >/= 50 years, male sex, urinary schistosomiasis, urinary stones and exposure to pesticides. To measure the adjusted OR and 95% confidence limits [CL] of each risk factor, stepwise logistic regression [LR] was computed to control for effects of the confounding variables. The main results of LR analysis were: 1- Elevated significant risk for SCC with urinary schistosomiasis [OR: 2.5, CL: 1.5-4.1], and urinary stones [OR: 2.2, CL: 1.1-4.2]. 2- Elevated risk for TCC with age of snore man 50 years [OR: 5.3, CL: 3.1-9.0], and urinary schistosomiasis [OR: 2.5, CL: 1.4-4.2]. 3- Increased risks for SCC and TCC, albeit non-significant on exposure to pesticides [OR: 2.0, CL: 0.9-4.8 for SCC], and [OR: 1.5 CL: 0.6-3.8 for TCC]. 4- Non-significant increased risk for SCC and TCC with cigarette smoking. Urinary schistosomiasis is a significant risk factor for SCC and TCC and its risk is almost unaffected by other confounding variables. Albeit statisticallt non-significant, the environmental and occupational factors are associated with high risk for BC