A prediction model for the incidence patterns of female breast cancers in Alexandria, Egypt

Breast cancer is the most common cancer among women in the world. Female breast cancer incidence has historically increased all over the world during the past decades. The purpose of this study was to estimate the patterns of female breast cancer incidence in Alexandria, Egypt, from 1972 to 2001. An up-to-date perspective systematically collected data on the incidence of female breast cancers was used. Age categories-estimated incidence over the 30 years period were computed. Time series analysis showed that incidence of breast cancers is increasing significantly during the studied period. Linear trend model was best fitted, with the studied interval and the estimated cancer cases per year taken into account. Age-incidence correlation showed a high correlation between age group of 40-50 years old and incidence. Analysis of the patterns for cancer incidence indicates that the highest occurrence of female breast cancer is shown in the age category of 45-50 years followed respectively by the age categories of 40-45 years, 50-55 years, 35-40 years and then 55-60 years. These findings support the growing body of evidence from female breast cancer incidence suggesting that age is a well-known risk factor for breast cancer susceptibility.     

Arsenic exposure and childhood cancer--a systematic review of the literature

The literature on environmental arsenic exposure and childhood cancer risk comprises 1) studies seeking childhood cancers among arsenic-exposed populations, 2) studies seeking arsenic exposure among childhood cancer cases, and 3) studies seeking associations in populations with both arsenic exposures and childhood cancer cases. No skin cancers were found in dermal examinations of over 25,000 children in Southwest Taiwan or West Bengal, India, with high drinking-water arsenic levels. Childhood cancer types were not different for those living near a Swedish smelter. In Montreal, Canada, children with acute lymphoblastic leukemia did not have drinking-water arsenic more frequently either prenatal or postnatal, and British children with cancer did not have early exposure to environmental sources of airborne arsenic. Neither hair arsenic levels in Woburn, Massachusetts, nor water arsenic levels in Fallon, Nevada, were elevated for children with leukemia. The literature, while limited, does not seem to support an association between arsenic exposure and childhood cancers.     

Risks of childhood cancer among Texas watersheds, based on mothers' living locations at the time of birth

Cancer is the most common fatal disease among US children. The fetus has reduced resistance to toxic injury and is especially prone to mutagenic injury because of the high rate of cell division. A fetus can be exposed to environmental toxins through maternal consumption of contaminated water. The objective of this study was to estimate the incidence risk for childhood cancers within each watershed in Texas. The approach modeled risk for 19 cancer histotypes incorporating correlations among the cancer types and spatial correlation. Several watersheds in a very large area known as the Central Great Plains of North Texas were associated with increased risk for astrocytoma. Two watersheds near Houston, Buffalo–San Jacinto and West Galveston Bay, had increased risk for renal cancer and acute lymphoid leukemia, respectively. A watershed in South Texas, the South Laguna Madre, had increased risk for atypical leukemias. The possibility that waterborne toxins cause these childhood cancers should be investigated further.     

A comparison of spatial clustering and cluster detection techniques for childhood leukemia incidence in Ohio, 1996 – 2003

Background  

Spatial cluster detection is an important tool in cancer surveillance to identify areas of elevated risk and to generate hypotheses about cancer etiology. There are many cluster detection methods used in spatial epidemiology to investigate suspicious groupings of cancer occurrences in regional count data and case-control data, where controls are sampled from the at-risk population. Numerous studies in the literature have focused on childhood leukemia because of its relatively large incidence among children compared with other malignant diseases and substantial public concern over elevated leukemia incidence. The main focus of this paper is an analysis of the spatial distribution of leukemia incidence among children from 0 to 14 years of age in Ohio from 1996–2003 using individual case data from the Ohio Cancer Incidence Surveillance System (OCISS).     

Childhood cancer incidence in French Brittany, 1991-2005

BackgroundThe aim of this study was to describe childhood cancer incidence in French Brittany from 1991 to 2005, as well as its temporal and geographical variations.MethodsChildhood cancer incidence was analyzed from the data from the Brittany child tumor registry. Crude rates, world age standardized rates and cumulative rates were estimated for all cancers and for each diagnosis group. Standardized rates were also estimated for each of the four Brittany districts. Poisson regressions were performed to estimate trends in annual rates and to compare incidence rates between 2000–2005 and 1991–1999 periods, and between districts.ResultsBetween 1991 and 2005, 1176 incident cancer cases were recorded in children younger than 15. Age standardized incidence was 169.5 cases per million of children per year. The most frequent cancers were leukemia (30%), central nervous system tumors (24%), lymphomas (12%) and neuroblastomas (8%). For the period 1991–2005 in Brittany, the risk of cancer diagnosis among children aged less than 15 years was 1/459. No significant increase trend was observed over the 1991–2005 period. There was however a significant or close to significant increase in incidence for lymphomas (RR: 1.38 [95%CI: 1.00–1.93]) and central nervous system tumors (RR: 1.24 [95%CI: 0.99–1.56]) between the 1991–1999 and 2000–2005 periods. A significant decrease trend was observed for renal tumors over the 1991–2005 period (Estimated Annual Percent Change = −7.6%, P = 0.02). There was no significant difference of incidence between the four districts of the region.ConclusionFor the period studied, childhood cancer incidence in French Brittany was lightly higher than for the whole country. Although increases in lymphomas and central nervous system tumors coincided with increasing use of a standardised data collection system for medical information, the data collected provided no evidence in favor of more complete data collection following implementation of the system.     

Impact of a statewide childhood vaccine program in controlling hepatitis A virus infections in Alaska

Historically, Alaska experienced cyclic hepatitis A virus (HAV) epidemics, and the HAV rate among Alaska Native people was significantly higher than among other racial/ethnic groups. We evaluated the impact of universal childhood vaccination, initiated in 1996, on HAV epidemiology in Alaska by analyzing HAV cases reported to the State of Alaska. HAV incidence in all age groups declined 98.6% from 60.0/100,000 in 1972–1995 to 0.9/100,000 in 2002–2007. The largest decrease (99.9%) was in Alaska Native people, whose incidence (0.3) in 2002–2007 was lower than the overall U.S. 2007 rate (1.0). Among age groups, the decrease (99.8%) among children aged 0–14 years was the largest. Routine childhood vaccination has nearly eliminated HAV infection in Alaska.     

Investigating possible effects of abestos in city water: surveillance of gastrointestinal cancer incidence in Duluth, Minnesota.

The recent discovery of over one million asbestos-like fibers per liter of Duluth tap water and the suggestive evidence of a link between certain gastrointestinal (GI) cancers and work exposure to asbestos fibers in the air prompted this study. GI cancer incidence data were gathered for Duluth in the same manner as data previously gathered for comparison cities, Minneapolis and St. Paul. Although some differences in GI cancer incidence occurred among the three cities in 1969-1971, there was no consistent pattern of statistically significant differences observed. The number of GI cancers diagnosed in Duluth residents in 1972 was similar to that in each of the previous three years. This study represents the start of ongoing cancer surveillance in Duluth.     

Are children with birth defects at higher risk of childhood cancers?

Birth defects may influence the risk of childhood cancer development through a variety of mechanisms. The rarity of both birth defects and childhood cancers makes it challenging to study these associations, particularly for the very rare instances of each. To address this limitation, the authors conducted a record linkage-based cohort study among Texas children born between 1996 and 2005. Birth defects in the cohort were identified through the Texas Birth Defects Registry, and children who developed cancer were identified by using record linkage with Texas Cancer Registry data. Over 3 million birth records were included; 115,686 subjects had birth defects, and there were 2,351 cancer cases. Overall, children with a birth defect had a 3-fold increased risk of developing cancer (incidence rate ratio (IRR) = 3.05, 95% confidence interval (CI): 2.65, 3.50), with germ cell tumors (IRR = 5.19, 95% CI: 2.67, 9.41), retinoblastomas (IRR = 2.34, 95% CI: 1.21, 4.16), soft-tissue sarcomas (IRR = 2.12, 95% CI: 1.09, 3.79), and leukemias (IRR = 1.39, 95% CI: 1.09, 1.75) having statistically significant elevated point estimates. All birth defect groups except for musculoskeletal had increased cancer incidence. Untangling the strong relation between birth defects and childhood cancers could lead to a better understanding of the genetic and environmental factors that affect both conditions.     

Geographical and temporal trends of childhood leukemia in relation to the nuclear plant in the Negev, Israel, 1960-1985.

Gardner et al. (Br Med J 1990; 300: 423-429) reported a high relative risk for childhood leukemia among children, aged 0-24 years at time of diagnosis, born to fathers employed at the Sellafield nuclear plant in the U.K. As a result we looked for spatial and temporal trends of childhood and young adult leukemia in the Negev, where a nuclear plant has been in operation since 1960. We divided the Negev into an Eastern part where plant employees are likely to live, and a Western part where this is quite unlikely. Reported leukemia cases were provided by the Israel Cancer Registry for the age group 0-24, and for the period 1960-1985. We checked this file against data obtained from the hospitals in the area. We added 6 more cases in the Eastern Negev, none in the Western Negev, and none of the reported cases was discarded. There was a total of 192 cases, of which 52% were acute lymphatic leukemia. Jewish and Bedouin children were studied separately. Among Jewish children the average annual incidence rate for the Eastern Negev was 2.76/100,000, the Western Negev 3.51. Over time the leukemia rates were consistently higher in the Western Negev among children aged 0-9 years, which holds especially for acute lymphatic leukemia. There was a sudden increase among girls born during the period 1970-1979 in the northern part of the Western Negev, which was not noticed among boys. No excess cases were found in the small towns around the plant.     

Prevalence of autism spectrum disorder among Nigerian children with intellectual disability: a stopgap assessment

The prevalence of autism spectrum disorder (ASD) among sub-Saharan African children with intellectual disability is about 0.7% more than three decades ago. During this period, the prevalence of ASD has been on the increase worldwide. Studies are not available in recent times addressing epidemiology of ASD among sub-Saharan African children. The present study assessed the prevalence of ASD among Nigerian children with intellectual disability. Forty four children with intellectual disability were assessed for diagnosis of childhood autism based on criteria specified in F84.0 section of International Classification of Diseases, Tenth Edition (ICD-10) Diagnostic Criteria for Research. Five (11.4%) of the children studied met the diagnostic criteria for childhood autism. Male/female ratio was 4:1. There is need for large scale epidemiological studies of ASD among sub-Saharan African children to clearly define the inter-relationship between ASD and intellectual disability in this population and to help in health care policy formulation.     

启东1972～2001年恶性肿瘤发病率时间趋势分析

目的运用时间趋势分析方法研究启东恶性肿瘤的变化趋势。方法利用启东肿瘤登记处积累的1972~2001年的登记资料,分析启东地区常见肿瘤发病率的变化趋势。计算粗率、调整率和变化百分比;配合调整率的线性回归模型,估计发病率的APC;同时分析各部位肿瘤发病率的年度变化贡献率及其统计学检验方法。结果男性中鼻咽癌、食管癌、胃癌、皮肤癌等部位发病率呈下降趋势,结肠癌、直肠癌、胰腺癌、肺癌、前列腺癌、膀胱癌、肾癌、脑肿瘤、非何杰金氏病以及白血病的发病率呈明显上升趋势;女性中鼻咽癌、胃癌、肠癌、皮肤癌、宫颈癌、肾癌等发病率呈下降趋势,结肠癌、直肠癌、胰腺癌、肺癌、卵巢癌、膀胱癌、脑肿瘤和白血病的发病率呈上升趋势。男性肿瘤中呈下降趋势贡献最大为胃癌,其次为肝癌;而发病率呈上升趋势的肿瘤中贡献最大的为肺癌,其次为直肠癌。在女性肿瘤呈下降趋势中贡献最大的是宫颈癌和胃癌;而发病率呈上升趋势的肿瘤贡献最大的是肺癌,其次为乳腺癌。结论时间趋势分析方法在研究恶性肿瘤发病率或死亡率变化趋势时值得推广。     

Clustering of childhood cancer in the inner city of Tehran metropolitan area: a GIS-based analysis

The aim of this study was both to map the childhood cancer incidence in the districts of Tehran metropolitan area and to explore possible clustering of cancer cases in the diverse environments of this area. All incidence cases of childhood cancers (age group under 15 years) belonging to the 22 districts of Tehran metropolis and occurring during the period of 1998 till 2002 were ascertained from three sources. Each case's place of residency was geo-referenced. The scan statistics cluster detecting technique was used to evaluate clustering of cases throughout Tehran. The overall incidence rate (IR) of childhood cancer was 176.3/1,000,000 children under 15 years of age. The lowest IR among both boys and girls was observed in district 22 (69.4/1,000,000) and the highest was observed in district 6 (242.09/1,000,000). The detection of clusters was performed for all cancer sites. All the cancer sites combined category showed clustering in the districts 7, 13, 8, 6, 3, 14, 12, 11, and 4. For this category, the clustering likelihood was marginally statistically significant (p-value=0.056), with an overall relative risk of 1.30. No statistically significant patterns of clustering were detected for other categories.     

Cancer in Connecticut, 1969

There were a total of 9788 newly-diagnosed cancers in Connecticut residents in 1969, an increase of 475 (5.1%) over 1968. 4620 were in males and 5168 in females. Tumors of the digestive organs were the most frequent, 2680 cases (27.4%). There were 1895 tumors of the genital organs (19.4%), 1421 of the breast (14.5%), and 1285 of the respiratory system (13.1%). The age-adjusted incidence rates for all tumors were 297.3 per 100,000 for males, an increase of 1% over 1968, and 295.1 for females, an increase of 5.4%. Among females the increased numbers of tumors were mostly breast, digestive organs, and lymphatic and hematopoietic tissues. For males cancer of the respiratory system showed the most increase. Female respiratory cancer declined slightly. Breast cancers in females increased 13.9%, the largest yearly increase ever recorded in Connecticut. The older age group (75-79 years) showed the most marked increase, from 311 to 403.1 per 100,000. Of the breast cancers 50.4% were localized, 37.2% had regional spread, and 7.8% remote metastases. In the others the stage was not recorded. Earlier diagnoses are obviously needed. In males cancer of the respiratory system increased from 63.7 per 100,000 in 1968 to 67.3 in 1969. Men over age 85 showed an increase of 156%. The rates in males for tongue and prostate cancer decreased. For children leukemia was the most frequent cancer, for girls 15-19 and boys 19-24 Hodgkin's disease was more frequent. In women aged 20-39 cancer of the cervix was most often diagnosed; after age 40, cancer of the breast; after age, 80, tumors of the large intestine. In men aged 25-34 cancer of the testes predominated; from 40-74, cancers of the lung and bronchus; and over 75, cancer of the prostate. During 1969 there were a total of 5073 cancer deaths, exclusive of nonmelanotic skin and myelofibrosis, 2759 males and 2314 females. 301.% of the deaths among males were digestive organ cancers, 27.8% were respiratory organ disease. Among females 29.4% of deaths were tumors of the digestive organs and 23.7% were breast cancers. Age-adjusted mortality rates were 176.6 per 100,000 for males and 122.4 for females, a slight decrease from 1968.     

Thyroid cancer incidence trends in Belarus: examining the impact of Chernobyl

BACKGROUND: While prior studies of thyroid cancer incidence within Belarus have increased since the 1986 Chernobyl reactor accident, the magnitude of increase is not well quantified. METHODS: Using Belarussian national cancer registry data, trends in average annual age-adjusted thyroid cancer incidence rates were examined by calendar year and gender. Incidence rates were also examined across specified time intervals, for specific age groups at diagnosis, and in 'higher exposure' regions compared with 'lower exposure' areas. RESULTS: Age-adjusted thyroid cancer incidence rates (adjusted to the WHO 2000 world population) have increased between 1970 and 2001 from 0.4 per 100 000 to 3.5 per 100 000 among males (+775%) and from 0.8 per 100 000 to 16.2 per 100 000 among females (+1925%). The relative increase among males (+1020%) and females (+3286%) in 'high exposure' areas exceeded increases among males (+571%) and females (+250%) in 'lower exposure' areas of Belarus. Dramatic increases in thyroid cancer incidence rate ratios were noted among both males and females and in all age groups. The highest incidence rate ratios were observed among people from 'higher exposure' areas ages 0-14 yr at time of diagnosis. CONCLUSIONS: Marked increases in the incidence of thyroid cancer have occurred over a relatively limited period of observation in all areas of the Republic of Belarus and among all age categories. The greatest increases have occurred among children, suggesting that a high prevalence of pre-existing iodine deficiency in combination with unique susceptibility among younger people might have contributed to potential carcinogenic exposures to the thyroid.     

Malignancies among adolescents and young adults in the province of Trieste,Italy, 1972-1993

We analysed incidence, survival and mortality from cancer among people aged 15-24 years resident in the province of Trieste, Italy, during 1972-1993, and evaluated the quality of the local diagnostic facilities and of the care provided by local hospital departments. We compared the results with those previously published on childhood cancer. We recorded 118 new cases of cancer (96% microscopically verified) corresponding to a rate, age-standardized to the world population, of 162.3 (standard error SE = 15.0) per million person-years. The diagnostic group with the highest rate was that of carcinomas (54.5; SE = 8.7; 40 cases). The diagnosis was reached at hospitals in the province of Trieste for 107 cases, with a median time of nine days (25th-75th percentile = 5-23) between admission and diagnosis. Among patients with leukaemias, lymphomas and brain tumours, this interval was longer than in children affected by the same neoplasms. One girl with cancer of the uterine cervix refused all treatment. The therapy of the other 117 cases were co-ordinated by 29 different departments of hospitals located in Trieste for 86 cases, in other Italian hospitals for 26 cases and in European hospitals for five cases. On the other hand, out of 123 childhood cancers 107 were co-ordinated by three departments in Trieste, seven by other Italian hospitals and nine by foreign hospitals. The 10-year survival probabilities of children with acute lymphoblastic leukaemia and non-Hodgkin lymphomas were higher than those of patients aged 15-24 years: 66.7% (SE = 9.1) vs 14.3% (SE = 13.2) and 77.8% (SE = 13.9) vs 40.0% (SE = 21.9), respectively.     

Parental age and risk of childhood cancers: a population-based cohort study from Sweden

BACKGROUND: Frequent germ line cells mutations were previously demonstrated to be associated with aging. This suggests a higher incidence of childhood cancer among children of older parents. A population-based cohort study of parental ages and other prenatal risk factors for five main childhood cancers was performed with the use of a linkage between several national-based registries. METHODS: In total, about 4.3 million children with their parents, born between 1961 and 2000, were included in the study. Multivariate Poisson regression was used to obtain the incidence rate ratios (IRR) and 95% confidence interval (CI). Children <5 years of age and children 5-14 years of age were analysed independently. RESULTS: There was no significant result for children 5-14 years of age. For children <5 years of age, maternal age were associated with elevated risk of retinoblastoma (oldest age group's IRR = 2.39, 95%CI = 1.17-4.85) and leukaemia (oldest age group's IRR = 1.44, 95%CI = 1.01-2.05). Paternal age was significantly associated with leukaemia (oldest age group's IRR = 1.31, 95%CI = 1.04-1.66). For central nervous system cancer, the effect of paternal age was found to be significant (oldest age group's IRR = 1.69, 95%CI = 1.21-2.35) when maternal age was included in the analysis. CONCLUSION: Our findings indicate that advanced parental age might be associated with an increased risk of early childhood cancers.     

Epidemiologic surveillance of childhood leukemia in Hungary over the past 21 years (1980-2000)

INTRODUCTION: Investigation of trends in incidence rates of childhood malignancies, especially leukaemia and thyroid cancers, is essential for the objective assessment of health consequences of the nuclear power plant accident in Ukraine in 1986. AIMS: This paper reports the results of the epidemiological surveillance of childhood leukaemia in Hungary from 1980 to 2000, according to the database of the Hungarian Paediatric Cancer Registry. METHODS: All childhood leukaemia cases diagnosed between the period of 1 January 1980 and 31 December 2000, age of 0-14, throughout Hungary have been recorded. The registration was done by the ten Paediatric Oncology Centres in Hungary. The total number of diagnosed and analysed cases was 1563. RESULTS: The incidence rate of childhood leukaemia showed a gradual, slow but significant increase of 1.2% per year over the observed period of time. There was neither any additional increase in the incidence following the accident, nor an increase in the cumulative incidence among the children born around the date of the accident. The accident did not cause a change regarding the infant leukaemia incidence in Hungary either. Apparent change in the geographical distribution of childhood leukaemia, which could be the result of the accident, was not detectable. CONCLUSION: The authors did not detect any change in the incidence of childhood leukaemia over the past 21 years in Hungary, which can be attributed to the nuclear power plant accident in Ukraine in 1986.     

Cancers of the cervix uteri and breast: changes in incidence rates in Bombay over the last two decades

The age-adjusted incidence rate of cervical cancer in Bombay has decreased over the last 20 years, whereas over the same period that of breast cancer increased slightly. Studies indicate that the incidence of cervical cancer is lower in successively later-born cohorts, but no cohort effect has been observed for breast cancer. Age at marriage is an important factor in the etiology of both these cancers, and it is plausible that the decrease in cervical cancer has resulted from the increase in age at marriage of women over the last 20 years in the city. The changing pattern of incidence of cancer for women in Bombay, among whom the incidence of breast cancer is the highest of all forms of cancer, indicates that, from a long-term perspective, cancer control programmes in India as a whole should aim at minimizing the risk of both cervical and breast cancer.     

Risk factors for acute leukemia in children: a review

Although overall incidence is rare, leukemia is the most common type of childhood cancer. It accounts for 30% of all cancers diagnosed in children younger than 15 years. Within this population, acute lymphocytic leukemia (ALL) occurs approximately five times more frequently than acute myelogenous leukemia (AML) and accounts for approximately 78% of all childhood leukemia diagnoses. Epidemiologic studies of acute leukemias in children have examined possible risk factors, including genetic, infectious, and environmental, in an attempt to determine etiology. Only one environmental risk factor (ionizing radiation) has been significantly linked to ALL or AML. Most environmental risk factors have been found to be weakly and inconsistently associated with either form of acute childhood leukemia. Our review focuses on the demographics of childhood leukemia and the risk factors that have been associated with the development of childhood ALL or AML. The environmental risk factors discussed include ionizing radiation, non-ionizing radiation, hydrocarbons, pesticides, alcohol use, cigarette smoking, and illicit drug use. Knowledge of these particular risk factors can be used to support measures to reduce potentially harmful exposures and decrease the risk of disease. We also review genetic and infectious risk factors and other variables, including maternal reproductive history and birth characteristics.