SummaryBackgroundCancer is a major cause of death in children worldwide, and the recorded incidence tends to increase with time. Internationally comparable data on childhood cancer incidence in the past two decades are scarce. This study aimed to provide internationally comparable local data on the incidence of childhood cancer to promote research of causes and implementation of childhood cancer control.MethodsThis population-based registry study, devised by the International Agency for Research on Cancer in collaboration with the International Association of Cancer Registries, collected data on all malignancies and non-malignant neoplasms of the CNS diagnosed before age 20 years in populations covered by high-quality cancer registries with complete data for 2001–10. Incidence rates per million person-years for the 0–14 years and 0–19 years age groups were age-adjusted using the world standard population to provide age-standardised incidence rates (WSRs), using the age-specific incidence rates (ASR) for individual age groups (0–4 years, 5–9 years, 10–14 years, and 15–19 years). All rates were reported for 19 geographical areas or ethnicities by sex, age group, and cancer type. The regional WSRs for children aged 0–14 years were compared with comparable data obtained in the 1980s.FindingsOf 532 invited cancer registries, 153 registries from 62 countries, departments, and territories met quality standards, and contributed data for the entire decade of 2001–10. 385 509 incident cases in children aged 0–19 years occurring in 2·64 billion person-years were included. The overall WSR was 140·6 per million person-years in children aged 0–14 years (based on 284 649 cases), and the most common cancers were leukaemia (WSR 46·4), followed by CNS tumours (WSR 28·2), and lymphomas (WSR 15·2). In children aged 15–19 years (based on 100 860 cases), the ASR was 185·3 per million person-years, the most common being lymphomas (ASR 41·8) and the group of epithelial tumours and melanoma (ASR 39·5). Incidence varied considerably between and within the described regions, and by cancer type, sex, age, and racial and ethnic group. Since the 1980s, the global WSR of registered cancers in children aged 0–14 years has increased from 124·0 (95% CI 123·3–124·7) to 140·6 (140·1–141·1) per million person-years.InterpretationThis unique global source of childhood cancer incidence will be used for aetiological research and to inform public health policy, potentially contributing towards attaining several targets of the Sustainable Development Goals. The observed geographical, racial and ethnic, age, sex, and temporal variations require constant monitoring and research.FundingInternational Agency for Research on Cancer and the Union for International Cancer Control.

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 districtspecific 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. Conflict of InterestThe authors declare that they have no commercial or other associations that might pose a conflict of interest in connection with this article. Ethical Approval:This study used data stripped of all personal identifiers and was approved by the University of Michigan Institutional Review Board and the Gharbiah Cancer Center Ethics Committee.Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptBreast. Author manuscript; available in PMC 2011 November 7. Conclusions-Higher incidence of breast cancer in urban and more developed populations might be related to higher xenoestrogens, as well as other endocrine disruptors and genotoxic substances.

Summary Head and Neck Cancer (HNC) has been studied in different regions of the world but little is known about its incidence patterns in the Middle East and Egypt. In this study from Egypt’s only population-based registry, we analyzed data from 1999-2006, to estimate incidence, incidence rate ratios (IRRs) and 95% confidence intervals (CIs) categorized by age, district and subsites. Overall urban incidence of HNC was twice or more that of rural incidence for both males (IRR = 2.59; 95% CI = 2.26, 2.97) and females (IRR = 2.00; 95% CI = 1.64, 2.43). Highest urban-rural difference for males was seen in 40-49 years (IRR = 2.79; 95% CI = 1.92, 4.05) and for females in 30-39 years (IRR = 2.94; 95% CI = 1.60, 5.40). Among subsites, highest incidence among males was for larynx (1.53/105) and among females for gum and mouth (0.48/105). Maximum urban-rural difference in males was for paranasal sinus (IRR = 4.66; 95% CI = 1.88, 11.54) and in females for lip (IRR = 8.91; 95% CI = 1.89, 41.98). The study underscores the patterns of HNC incidence in Egypt while indicating the need for future analytical studies investigating specific risk factors of HNC in this population.

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 urbanrural 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.

Chronic mastitis is a prolonged inflammatory breast disease, and little is known about its etiology. We identified 85 cases and 112 controls from 5 hospitals in Morocco and Egypt. Cases were women with chronic mastitis (including periductal, lobular, granulomatous, lymphocytic, and duct ectasia with mastitis). Controls had benign breast disease, including fibroadenoma, benign phyllodes, and adenosis. Both groups were identified from histopathologically diagnosed patients from 2008 to 2011, frequency-matched on age. Patient interviews elicited demographic, reproductive, breastfeeding, and clinical histories. Cases had higher parity than controls (OR = 1.75, 1.62–1.90) and more reported history of contraception use (OR = 2.73, 2.07–3.61). Cases were less likely to report wearing a bra (OR = 0.56, 0.47–0.67) and less often used both breasts for breastfeeding (OR = 4.40, 3.39–5.72). Chronic mastitis cases were significantly less likely to be employed outside home (OR = 0.71, 0.60–0.84) and more likely to report mice in their households (OR = 1.63, 1.36–1.97). This is the largest case-control study reported to date on risk factors for chronic mastitis. Our study highlights distinct reproductive risk factors for the disease. Future studies should further explore these factors and the possible immunological and susceptibility predisposing conditions.