Urban-rural differences in breast cancer incidence in Egypt (1999-2006).

OBJECTIVE: To describe urban-rural differences in breast cancer incidence in Gharbiah, Egypt and to investigate if these differences could be explained by known risk factors of breast cancer. METHODS: We used data from the population-based cancer registry of Gharbiah, Egypt to assess breast cancer incidence from 1999 through 2006. The Egyptian census provided data on district-specific population, age, and urban-rural classification. Incidence patterns of breast cancer by district and age-specific urban-rural differences were analyzed. RESULTS: Overall, incidence rate of breast cancer was three to four times higher in urban areas than in rural areas (60.9/10(5)-year for urban areas versus 17.8/10(5)-year for rural areas; IRR=3.73, 95% CI=3.30, 4.22). Urban areas had consistently higher incidence of breast cancer across all age-groups for all years. Higher incidence of breast cancer was also seen in the more developed districts of Tanta and El-Mehalla. CONCLUSIONS: Higher incidence of breast cancer in urban and more developed populations might be related to higher exposure to xenoestrogens, as well as other endocrine disruptors and genotoxic substances.

Epidemiologic risk factors of hepatocellular carcinoma in a rural region of Egypt.

BACKGROUND: Hepatocellular carcinoma (HCC) is a major health problem worldwide, including Egypt. In the recent past, HCC has become the second most prevalent cancer among men in Egypt. Since HCC has not been well studied in the rural population of Egypt, this case-control study was conducted to investigate the epidemiologic risk factors of HCC in the predominantly rural region of Gharbiah, Egypt. METHODS: A total of 150 cases and 150 controls matched to cases on age (±5 years) and sex were recruited from the Gharbiah Cancer Society and Tanta Cancer Center. Exposure data were collected by an interviewer-administered standardized questionnaire about epidemiologic, occupational, medical and family history of HCC. Conditional logistic regression was utilized to calculate unadjusted and adjusted odds ratios (ORs) and 95% confidence intervals (CI). The effect modification of HCC risk between viral infection and environmental risk factors was also assessed. RESULTS: Being an industrial worker was an independent risk for developing HCC (OR 3.54, 95% CI 1.18, 10.63) after adjusting for viral infection, schistosomiasis and tobacco smoking. High relative risk of HCC was observed among HCV-infected individuals who were farmers (OR 9.60, 95% CI 3.72, 24.76), industrial workers (OR 12.90, 95% CI 4.33, 38.43) or active smokers (OR 5.95, 95% CI 2.20, 16.08). CONCLUSION: Occupational exposure may play an important role in the development of HCC. Farming, industrial exposures and cigarette smoking may increase the risk of HCC among HCV-seropositive individuals. Future research focusing on mechanisms of occupational exposures among HCV patients in this population is needed.

Urban-rural differences in breast cancer incidence by hormone receptor status across 6 years in Egypt.

Breast cancer incidence is higher in developed countries with higher rates of estrogen receptor positive (ER+) tumors. ER+ tumors are caused by estrogenic exposures although known exposures explain approximately 50% of breast cancer risk. Unknown risk factors causing high breast cancer incidence exist that are estrogenic and development-related. Xenoestrogens are such risk factors but are difficult to study since developed countries lack unexposed populations. Developing countries have urban-rural populations with differential exposure to xenoestrogens. This study assessed urban-rural breast cancer incidence classified by hormone receptor status using data from Gharbiah population-based cancer registry in Egypt from 2001 to 2006. Urban ER+ incidence rate (per 100,000 women) was 2-4 times (IRR = 3.36, 95% CI = 4.84, 2.34) higher than rural incidence rate. ER-incidence rate was 2-3 times (IRR = 1.86, 95% CI = 2.38, 1.45) higher in urban areas than in rural areas. Our findings indicate that urban women may probably have a higher exposure to xenoestrogens.

Concordance of DNA methylation pattern in plasma and tumor DNA of Egyptian hepatocellular carcinoma patients.

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the fourth leading cause of cancer mortality globally. HCC incidence has doubled in Egypt in the past 10 years, which could be attributed to the high prevalence of hepatitis C virus (HCV) and hepatitis B virus (HBV), although HBV rates have declined after the introduction of the vaccine in 1992. Aberrant DNA methylation may play an important role in hepatocarcinogenesis. Liver biopsy is the current gold standard for methylation studies; however, imaging techniques often suffice for diagnosis making tissue samples increasingly scarce. The efficacy of conducting DNA methylation studies in molecular epidemiology using plasma DNA is still unclear. We compared tumor methylation profile for the tumor suppressor genes APC, FHIT, p15, p16, and E-cadherin in tumor tissues and plasma to test the concordance between the two types of specimen from the same HCC patients. Twenty-eight HCC patients with matching tissue and plasma DNA were recruited from a case-control study in Gharbiah, Egypt. Concordance between the tissue and plasma was statistically significant in all five genes as follows: APC (23/28, 82.1%, p=0.001), FHIT (24/28, 85.7%, p=.0001), p15 (25/28, 89.2%, p=0.045), p16 (19/28, 67.9%, p=0.037), and E-cadherin (22/28, 78.5%, p=0.0008). The average specificity was 90%, 86%, 96%, 86%, and 100%, respectively. There was no significant association between methylation and hepatitis viral infection for any of the genes tested in this study. Plasma DNA can be reliable for testing methylation profile in liver cancer patients in this population. Future studies on a larger sample size should investigate methylation profile in populations with higher rates of HBV, HCV, and other risk factors.

Incidence analyses of bladder cancer in the Nile delta region of Egypt.

Bladder cancer is the most common malignancy among Egyptian males and previously has been attributed to Schistosoma infection, a major risk factor for squamous cell carcinoma (SCC). Recently, transitional cell carcinoma (TCC) incidence has been increasing while SCC has declined. To investigate this shift, we analyzed the geographical patterns of all bladder cancers cases recorded in Egypt's Gharbiah Population-Based Cancer Registry from 1999 through 2002. Data on tumor grade, stage, and morphology, as well as smoking, community of residence, age and sex, were collected on 1209 bladder cancer cases. Age-adjusted incidence rates were calculated for males, females, and the total population for the eight administrative Districts and 316 communities in Gharbiah. Incidence Rate Ratios (IRR) and 95% confidence intervals (CI) were computed using Poisson Regression. The male age-adjusted incidence rate (IR) in Gharbiah Province was 13.65/100,000 person years (PY). The District of Kotour had the highest age-adjusted IR 28.96/100,000 among males. The District of Kotour also had the highest IRR among all Districts, IRR=2.15 95% CI (1.72, 2.70). Kotour's capital city had the highest bladder cancer incidence among the 316 communities (IR=73.11/100,000 PY). Future studies on sources and types of environmental pollution and exposures in relation to the spatial patterns of bladder cancer, particularly in Kotour District, may improve our understating of risk factors for bladder cancer in the region.

The changing patterns of bladder cancer in Egypt over the past 26 years.

OBJECTIVE: To evaluate temporal changes in histopathological types of bladder cancer and to assess associated changes in demographic, epidemiologic, and lifestyle risk factors. METHODS: We abstracted data from all available medical records from the National Cancer Institute of Cairo University (NCI-Cairo). Six calendar years representing 5-year periods between 1980 and 2005 were evaluated. Information on demographics, schistosomal infection, clinical symptoms of bladder cancer, and tumor pathology was abstracted. RESULTS: During this 26-year period, important changes in the frequency of histopathological types of bladder cancer occurred. We found a statistically significant association between time period of diagnosis and histopathological type. Patients diagnosed in 2005 had a sixfold higher odds associated with transitional cell carcinoma compared to those patients diagnosed in 1980 (odds ratio (OR) 6.00 (95% CI 4.00-8.97)). CONCLUSIONS: These data strongly suggest that the histopathological profile of bladder cancer in Egypt has changed significantly over the past 26 years. Historically, squamous cell carcinoma was the predominant form of bladder cancer in Egypt; however transitional cell carcinoma has become the most frequent type. These results corroborate findings from a few small-scale hospital-based studies which conclude that the etiology of bladder cancer in Egypt has changed significantly over the past 26 years.

Patterns of hepatocellular carcinoma incidence in Egypt from a population-based cancer registry.

AIM: Hepatocellular carcinoma (HCC) is increasing worldwide, and is frequently attributed to rising rates of hepatitis C virus infection and interactions between viral and environmental risk factors. Because of Egypt's unique risk factor profile, we analyzed data from the Gharbiah Population-Based Cancer Registry for the period 1999-2003 to characterize demographic and geographic patterns of cases in this province. METHODS: We calculated age- and sex-specific and age- and sex-standardized HCC incidence rates for the eight districts in Gharbiah. We also compared rates from Gharbiah with the USA (US Surveillance Epidemiology and End RESULTS [SEER] database). RESULTS: The analysis revealed a higher incidence in males than in females, significant geographic variations among districts, and a higher incidence in Gharbiah than that reported by SEER. CONCLUSION: The findings of this study document the heterogeneous distribution of HCC at regional and international levels. This population-based registry offers the opportunity for careful representative studies of various etiologies, particularly infectious and/or environmental factors that may contribute to risk.

Knowledge gained after a brief CME module on breast cancer diagnosis.

BACKGROUND: In developing countries, continuing medical education (CME) is lacking and physicians' knowledge of cancer control may also be lacking. METHOD: We evaluated knowledge of 144 primary care physicians in Egypt and 50 in Tunisia regarding breast cancer (BC) and inflammatory BC (IBC) in particular. We invited the physicians to pretesting, presentation of an educational module, and post-testing. RESULTS: We found significant improvement in knowledge about risk factors for IBC and BC, importance of early detection and clinical examination, and referral of IBC cases. The variables that were independently associated with improved BC knowledge, were rural practice location, being a female physician, and greater numbers of BC patients seen in the last year. CONCLUSION. We developed and evaluated a CME module to improve BC diagnostic knowledge of primary care physicians in developing countries. The evaluation showed that physicians most lacking in this knowledge had the greatest gains. With the anticipated adoption of this module in Egypt and Tunisia, we expect to see more appropriate referrals to cancer centers. These results could guide future oncology CME for physicians in developing countries.