Abstract 1812: Urban-rural distribution of cancer profiles in Gharbiah, Egypt
Authors: Dey Subhojit , Soliman Amr S. , Zhang Zhenzhen , Hablas Ahmad , Seifeldin Ibrahim A. , Ramadan Mohamed , El-Hamzawy Hesham , Harford Joe , Merajver Sofia D. 
Published: February 2011

Abstract
In our previous studies, we observed higher incidence for certain malignancies in urban areas in Gharbiah, Egypt compared to rural areas. Here we present the results of our further investigations on urban-rural differences for other cancer sites in the same population. Using data from the Gharbiah population-based cancer registry, we compared urban-rural incidence rates of the ten most common cancers in men and women over four years (1999-2002). Census data provided accurate denominators and standard urban-rural definitions. Crude and adjusted incidence rates (IRs), incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were estimated using Poisson regression. Comparing genders, incidence of all cancer sites was higher among men than women for both urban and rural areas with laryngeal cancer (IRR = 13.75, 95% CI = 4.96, 38.10) and liver cancer (IRR = 4.50, 95% CI = 3.63, 5.68) in rural men being much higher than rural women. Also, bladder cancer among urban men was much higher than in urban women (IRR = 5.12, 95% CI = 4.13, 6.35). Among both males and females, urban incidence was higher than rural incidence for all cancer sites. Among males, urban-rural incidence difference was highest for prostate cancer (IRR = 4.85, 95% CI = 3.76, 6.26) followed by larynx (IRR = 4.19, 95% CI = 3.06, 5.73), and brain and CNS (IRR = 3.95, 95% CI = 3.00, 5.20). Among females, urban-rural incidence difference was highest for uterus (IRR = 6.05, 95% CI = 4.17, 8.78) followed by larynx (IRR = 5.54, 95% CI = 1.74, 17.61), and breast (IRR = 4.87, 95% CI = 4.50, 5.27). Analysis of the urban-rural differences by district revealed that among males and females, urban incidence was higher than rural incidence in most of the 8 districts of Gharbiah, for all cancer sites. The highest urban-rural difference within districts for males was seen for laryngeal cancer in El Santa (IRR = 29.45, 95% CI = 10.63, 81.61) followed by prostate cancer in Kafr-El-zayat (IRR = 15.58, 95% CI = 5.20, 46.69). Noticeably, we discovered that El-Santa had the highest difference of urban-rural incidence for most cancer sites except prostate and pancreas. Among females, the highest urban-rural difference within districts was seen for uterine cancer in El Santa (IRR = 15.98, 95% CI = 2.69, 95.10) followed by lung cancer in Kotoor (IRR = 10.78, 95% CI = 3.14, 37.06). High smoking and higher exposure to S. hematobium followed by parenteral anti-schistosomal therapy among men in Egypt may have led to an increase in laryngeal, bladder, and liver cancer. Better healthcare access and more awareness are most likely responsible for high ascertainment of prostate, brain & CNS in urban males. Among urban women, higher exposure to environmental risks and better access might be responsible for higher rates of uterine and breast cancer. Urban-rural differences within districts need to be investigated with respect to industrial pollution, pesticide use, and other toxins to further define the etiology of various cancers in this population.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1812.