International variations in the incidence of childhood lymphomas

Summary. The International Agency for Research on Cancer has coordinated a worldwide study of childhood cancer incidence, with data provided by contributors from over 50 countries. We present here the results on lymphomas from this study and other sources. Hodgkin's disease had a relatively high incidence in North Africa and West Asia and a low incidence throughout East Asia. In populations of predominantly European origin, the highest rates tended to be in warmer countries of lower latitude. In industrialised Western countries, the incidence increased steeply with age and was low in childhood compared with that in young adults whereas elsewhere the increase in incidence between childhood and adults aged 20–34 was much less marked. The age-distribution of Hodgkin's disease in childhood appears to be related to levels of socio-economic development but the total incidence seems to be determined more by ethnic and environmental factors. The highest incidence of Burkitt's lymphoma occurred in tropical Africa and Papua New Guinea. Elsewhere, Burkitt's lymphoma was rare, though the incidence was higher in Spain, North Africa and the Middle East than in other areas. In most Western countries, a third of all non-Hodgkin lymphomas may be Burkitt's. There was no consistent pattern in the incidence of other non-Hodgkin lymphomas except for a tendency towards higher rates around the Mediterranean and in some Latin American registries.     

A fifteen-year review of lymphomas in a Nigerian tertiary healthcare centre

In Africa, epidemiological data on the effect of the HIV epidemic on the occurrence of lymphomas are scanty. The 1990s witnessed the alarming rates of HIV/AIDS in Nigeria. The prevalence of HIV/AIDS in Nigeria increased from 1.8% in 1991 to 4.4% in 2005. The aim of this study was to determine whether there have been any changes in the frequency and pattern of lymphomas in view of the HIV/AIDS epidemic in the country. This is a retrospective study of all lymphoma cases diagnosed during 1991-2005. The prevalence of lymphomas declined from 1.4% to 0.7% of surgical biopsies during 1991-2005. There was a decline in the proportion of high-grade non-Hodgkin lymphoma and Burkitt's lymphoma from 79.1% and 45.8% respectively to 21.1% and 13.6% respectively. There is a suggestion that the HIV/AIDS epidemic in the country may not have influenced the pattern of occurrence of both major histomorphological types of lymphoma in Ibadan.     

Incidence of childhood cancer in Thailand 1988–1991

Summary. Incidence rates of cancers of childhood in Thailand are presented for the first time, and compared with results from cancer registries in Asia, Europe and the USA. As elsewhere in the world, leukaemia (principally acute lymphocytic), brain tumours and lymphomas comprise two-thirds of all childhood neoplasms. Carcinomas are rare, but the principal sites (liver, nasopharynx, thyroid and salivary gland) are extremely unusual elsewhere. Several features of the cancer partem correspond to that in other Asian populations (China, Japan, Philippines), in particular the low incidence of Hodgkin's disease, Wilms' tumour and Ewing's sarcoma. Conversely, Burkitf s lymphoma is more common than elsewhere, although this may represent increasing awareness of this diagnosis amongst clinicians in recent years.     

Prevalence and trends of overweight among preschool children in developing countries

BACKGROUND: Obesity during childhood is a matter of growing concern. Several reports show increasing rates of obesity in developed countries, whereas the extent of the problem in developing countries remains unknown. OBJECTIVE: The aim of this study was to fill this gap by quantifying the prevalence and trends of overweight among preschool children in developing countries. DESIGN: One hundred sixty nationally representative cross-sectional surveys from 94 countries were analyzed in a standardized way to allow comparisons across countries and over time. Overweight was defined as a weight-for-height >2 SDs from the National Center for Health Statistics/World Health Organization international reference median. Prevalences of wasted children (< -2 SDs) are also presented to enable comparisons between both ends of the distribution. RESULTS: The global prevalence of overweight was 3.3%. Some countries and regions, however, had considerably higher rates, and overweight was shown to increase in 16 of 38 countries with trend data. Countries with the highest prevalences of overweight are located mainly in the Middle East, North Africa, and Latin America. Rates of wasting were generally higher than those of overweight; Africa and Asia had wasting rates 2.5-3.5 times higher than overweight rates. Countries with high wasting rates tended to have low overweight rates and vice versa. CONCLUSIONS: These estimates show that attention should be paid to monitoring levels and trends of overweight in children. This, however, should not be done at the expense of decreasing international commitments to alleviating undernutrition. The data presented confirm that undernutrition remains a major public health problem worldwide.     

Childhood cancer survival in Cuba

Reports dealing with childhood cancer population-based survival have not yet been published in Cuba. A survival study including cases reported to the National Cancer Registry in the period 1988–1989 have been accomplished in the National Cancer Registry of Cuba. A comprehensive view of its results in childhood cancer is intended to be shown in this paper. All sites childhood cancer cases aged below 15 years (400) and reported in this period were included derived from a total of 578 incident cases. Vital status of cases was checked-up to December of 1994 by a mixed follow-up. Survival analysis was achieved by the life-table method using the SPSS for Windows software. Relative survival rates were not included because no differences were appreciated with the observed ones. Cases between 0–4 years and females account for the highest frequencies. Leukaemia accounts for 27% of the cases, followed by lymphomas and tumours of the central nervous system. Lymphoid and non-lymphoid acute leukaemia had 41 and 9% 5-year survival rate respectively being the latter comparable with Bangalore, India (10%). For lymphomas, Hodgkin's disease present better prognosis compared with non-Hodgkin lymphoma with 73 and 35% 5-year survival rates, respectively. Figures are comparable to the corresponding to Bangalore, India (72 and 33%, respectively). For time trends survival distribution were compared by period of diagnosis (1982/1988–1989). In all cases differences resulted statistically non-significant with lower rates for 1988–1989 except for lymphomas. International reports show increasing time trends for childhood cancer. Nevertheless, these results may serve as a milestone for future comparisons, corresponding with the creation of the National Program for Childhood Cancer Control and future studies will confirm the success of its measures.     

Maternal mortality at the end of a decade: signs of progress?

Maternal mortality is an important measure of women's health and indicative of the performance of health care systems. Several international conferences, most recently the Millennium Summit in 2000, have included the goal of reducing maternal mortality. However, monitoring progress towards the goal has proved to be problematic because maternal mortality is difficult to measure, especially in developing countries with weak health information and vital registration systems. This has led to interest in using alternative indicators for monitoring progress. This article examines recent trends in two indicators associated with maternal mortality: the percentage of births assisted by a skilled health care worker and rates of caesarean delivery. Globally, modest improvements in coverage of skilled care at delivery have occurred, with an average annual increase of 1.7% over the period 1989-99. Progress has been greatest in Asia, the Middle East and North Africa, with annual increases of over 2%. In sub-Saharan Africa, on the other hand, coverage has stagnated. In general, caesarean delivery rates were stable over the 1990s. Countries where rates of caesarean deliveries were the lowest--and where the needs were greatest--showed the least change. This analysis leads us to conclude that whereas there may be grounds for optimism regarding trends in maternal mortality in parts of North Africa, Latin America, Asia, and the Middle East, the situation in sub-Saharan Africa remains disquieting.     

Epidemiology of Kawasaki disease in Asia, Europe, and the United States

Kawasaki disease (KD) is a systemic vasculitis that mainly affects children younger than 5 years. Although Dr. Tomisaku Kawasaki first reported KD over 40 years ago, the cause of the disease remains unknown. Currently, KD has been diagnosed in more than 60 countries, including those in Asia, the Middle East, Latin America, and Africa, as well as in North America and Europe. The purpose of this review is to describe the epidemiologic features of KD--particularly its incidence, seasonality, and the occurrence of coronary artery abnormalities--primarily in Japan and the United States, but also in Europe and other Asian countries.     

The frequency of Epstein-Barr virus infection and Burkitt's lymphoma at high and low altitudes in East Africa

Burkitt's lymphomas (BL) is frequent in the tropical lowland of Africa but rare--even in the tropics--at altitudes higher than 5,000 feet above sea level. Serological surveys were carried out in Uganda and Tanzania to see whether the variation in BL incidence from high to low areas is paralleled by a variation in the extent of infection with the putative Epstein-Barr virus. Sera were collected from samples of the general child population living at high and low altitudes in the West Nile District in Uganda and in North Mara, Tanzania. All sera from these surveys were tested for anti-EBV antibodies to Viral Capsid Antigens (VCA) and to Early Antigens (EA) at the International Agency for Research on Cancer in Lyon, France. The results showed that both the prevalence and the strength of positive EBV (VCA and EA) titres are nearly similar in the lowlands and on the high plateux in East Africa. This lack of association between BL incidence and extent of EBV infection fails to support the notion of a causal role between the virus and the tumor, but does not totally exclude this possibility since some other environmental factor which is essential for BL development, may have a geographical distribution that parallels that of BL.     

“一带一路”沿线国家登革热流行情况及变化趋势研究

目的分析2019年"一带一路"沿线国家登革热流行现状及2013-2019年登革热发病率变化趋势。方法利用2019年全球疾病负担研究(GBD)登革热年龄标准化发病率(ASR)数据, 描述2019年"一带一路"区域登革热流行现状, 并计算2013-2019年ASR的年估计百分比变化(EAPC)评估流行趋势。结果 2019年GBD登革热数据显示145个"一带一路"沿线国家中93个(64.14%)国家有登革热流行。2019年登革热发病率>3 000.00/10万的国家共有11个, 9个国家在大洋洲;其次16个国家发病率在1 000.00/10万～2 999.99/10万, 10个国家在亚洲。非洲(58.14%, 25/43)、北美洲(72.73%, 8/11)及南美洲(66.67%, 4/6)等区域的多数国家发病率在500.00/10万～999.99/10万。大洋洲90.00%(9/10)的国家登革热发病率为上升趋势, 斐济上升趋势最明显(EAPC=18.22, 95%CI:12.91～23.77);其次亚洲18.18%(4/22)的国家登革热发病率呈上升趋势, 菲律宾上升趋势最明显(E...     

Incidence of childhood cancer in Ho Chi Minh City, Vietnam, 1995-97

Incidence rates of childhood cancer for the city of Ho Chi Minh are presented for the first time. For the 3-year period 1995-97, a total of 302 cancer cases were registered in children under 15 years of age, with a male to female ratio of 1.1. The overall crude rate was 78.8 and the age-standardised incidence rate was 88.4 per million person-years, which was low in comparison with other countries in eastern Asia and with the predominantly white population of Australia. Leukaemia (principally acute lymphocytic), brain tumours and lymphomas were the most common childhood neoplasms, which is consistent with the pattern observed in other registries of the region. The rate of retinoblastoma was higher than in the other regional registries. On the other hand, no cases of hepatocellular carcinoma were registered.     

Haematological malignancies in childhood in Croatia: Investigating the theories of depleted uranium, chemical plant damage and ‘population mixing’

Some of potential causes proposed to explain the reported increase of haematological malignancies in childhood during or after the war period in several countries include depleted uranium, chemical pollution and population mixing theory. The aim of this study was to define the population of Croatian children aged 0-14 years who were potentially exposed to each of those risks during the war and to investigate any possible association between the exposure and the incidence of haematological malignancies. The authors analyzed the data reported by the Cancer Registry of Croatia during the pre-war period (1986-1990), war period (1991-1995) and post-war period (1996-1999). In the group of 10 counties potentially exposed to depleted uranium and two counties where chemical war damage occurred, no significant difference in incidence of the studied haematological malignancies was noted in comparison to pre-war period. The incidence of lymphatic leukaemia significantly increased in four counties where population mixing had occurred during the war period, supporting the 'mixing theory'. In those counties, the incidence of Hodgkin's lymphoma decreased during and after the war. In Croatia as a whole, decreases in incidence of myeloid leukaemias during war and non-Hodgkin lymphoma after the war were noted.     

Fathers' occupational contacts and risk of childhood leukemia and non-hodgkin lymphoma

BACKGROUND: There is evidence to suggest that childhood leukemia and non-Hodgkin lymphoma have an infective etiology. We investigated the risk of childhood leukemia and non-Hodgkin lymphoma in relation to paternal occupational contact with other individuals, a surrogate for potential exposure to infection. METHODS: We carried out a case-control study using 792 cases from the Northern Region Young Persons' Malignant Disease Registry, United Kingdom, 1968-1997, and 2 large population-based control groups. Paternal occupations at birth were classified as having standard, high, or very high levels of contact. Conditional logistic regression was used in the analysis. RESULTS: There was an increased risk of childhood leukemia and non-Hodgkin lymphoma in those children whose fathers' occupational contacts were high or very high compared with standard (odds ratio = 1.3; 95% confidence interval = 1.0-1.5). The excess risk in the very high group was most pronounced for 245 cases of acute lymphoblastic leukemia aged 2 to 5 years at diagnosis (1.5; 1.1-2.1). The risk with paternal occupational contacts was greater in rural areas, although it was also present in urban areas. The risks of leukemia and non-Hodgkin lymphoma were also higher among the offspring of men employed as policemen, sales representatives, or teachers. CONCLUSIONS: Our findings are consistent with the hypothesis of an infective etiology for childhood leukemia and non-Hodgkin lymphoma, and they add to the evidence that infections could be transmitted to children by adults.     

Non Hodgkin's lymphoma and chronic hepatitis C virus infection: a non-fortuitous association. Two case reports

Many authors suggest the role of hepatitis C virus (HCV) infection in the pathology of B-cell non Hodgkin's lymphomas; this is based on epidemiological, physiopathological and therapeutic arguments. The frequency of the association with hepatitis C virus infection is variable in the different study (1 to 30%). We report two cases of hepatitis C virus infection in association with non Hodgkin's lymphomas. The first case presented a low grad splenic and nodal non-Hodgkin's lymphoma associated with hepatitis C virus infection and complicated by hepato-cellular carcinoma. The second case presented a high grad nodal non-Hodgkin's lymphoma associated with HCV infection. Our cases report confirms the hypothesis of a key role of hepatitis C virus in the pathogenesis of B-cell lymphoproliferative disorders and in particular the non-Hodgkin's lymphoma. Although of several hypothesis concerning the ethiopathogenic mechanisms of this association, new studies will necessary to improve the real mechanism of this association     

The worldwide incidence of preterm birth: a systematic review of maternal mortality and morbidity

Objective

To analyse preterm birth rates worldwide to assess the incidence of this public health problem, map the regional distribution of preterm births and gain insight into existing assessment strategies.

Methods

Data on preterm birth rates worldwide were extracted during a previous systematic review of published and unpublished data on maternal mortality and morbidity reported between 1997 and 2002. Those data were supplemented through a complementary search covering the period 2003–2007. Region-specific multiple regression models were used to estimate the preterm birth rates for countries with no data.

Findings

We estimated that in 2005, 12.9 million births, or 9.6% of all births worldwide, were preterm. Approximately 11 million (85%) of these preterm births were concentrated in Africa and Asia, while about 0.5 million occurred in each of Europe and North America (excluding Mexico) and 0.9 million in Latin America and the Caribbean. The highest rates of preterm birth were in Africa and North America (11.9% and 10.6% of all births, respectively), and the lowest were in Europe (6.2%).

Conclusion

Preterm birth is an important perinatal health problem across the globe. Developing countries, especially those in Africa and southern Asia, incur the highest burden in terms of absolute numbers, although a high rate is also observed in North America. A better understanding of the causes of preterm birth and improved estimates of the incidence of preterm birth at the country level are needed to improve access to effective obstetric and neonatal care.     

Global trends in breast cancer incidence and mortality 1973-1997

BACKGROUND: Worldwide, breast cancer is the most common cancer and is the leading cause of cancer death among women. METHODS: To describe global trends, we compared age-adjusted incidence and mortality rates over three decades (from 1973-77 to 1993-97) and across several continents. RESULTS: Both breast cancer incidence and mortality rates varied 4-fold by geographic location between countries with the highest and lowest rates. Recent (1993-1997) incidence rates ranged from 27/100,000 in Asian countries to 97/100,000 among US white women. Overall, North American and northern European countries had the highest incidence rates of breast cancer; intermediate levels were reported in Western Europe, Oceania, Scandinavia, and Israel; and Eastern Europe, South and Latin America, and Asia had the lowest levels. Breast cancer incidence rose 30-40% from the 1970s to the 1990s in most countries, with the most marked increases among women aged > or =50 years. Mortality from breast cancer paralleled incidence: it was highest in the countries with the highest incidence rates (between 17/100,000 and 27/100,000), lowest in Latin America and Asia (7-14/100,000), and rose most rapidly in countries with the lowest rates. CONCLUSIONS: Breast cancer incidence and mortality rates remain highest in developed countries compared with developing countries, as a result of differential use of screening mammograms and disparities in lifestyle and hereditary factors. Future studies assessing the combined contributions of both environmental and hereditary factors may provide explanations for worldwide differences in incidence and mortality rates.     

Study of pathogenetic role of Epstein-Barr virus in Hungarian patients with B-cell non-Hodgkin lymphomas

INTRODUCTION: The Epstein-Barr virus is a member of herpesvirus family. It plays an important role in the etiopathogenesis of Burkitt lymphoma, other B-cell non-Hodgkin lymphomas, nasopharyngeal carcinoma, X chromosome-linked lymphoproliferative disease, Hodgkin lymphomas and a part of T-cell lymphomas. It has been suggested that association of Epstein-Barr virus with lymphomas and its pathological significance in disease varies in different geographical areas. The aim of our study was to reveal the role of Epstein-Barr virus in B-cell non-Hodgkin lymphomas diagnosed in Hungary. The authors asked: A) What is the frequency of the presence of virus genome in the biopsy specimen from B-cell non-Hodgkin patients? B) Which types of virus latency can be observed? PATIENTS AND METHODS: Genomic DNA and EBER-specific RNA of Epstein-Barr virus in paraffin-embedded specimens were detected by polymerase chain reaction and in situ hybridisation, respectively. RESULTS: Out of 36 B-cell non-Hodgkin lymphoma cases, 16 (45%) were found to be positive for Epstein-Barr virus by the above methods. Expression of latency genes, nuclear antigene-2 and latent membrane protein-1 was studied by immunohistochemical technique. The 16 virus-positive non-Hodgkin lymphoma cases showed Epstein-Barr virus latency types II. (37%) or III. (63%). CONCLUSIONS: The authors data suggest that Epstein-Barr virus may be associated with the development of B-cell non-Hodgkin lymphomas in Hungarian patients.     

Cancer risk and parental pesticide application in children of Agricultural Health Study participants

Parental exposure to pesticides may contribute to childhood cancer risk. Through the Agricultural Health Study, a prospective study of pesticide applicators in Iowa and North Carolina, we examined childhood cancer risk and associations with parental pesticide application. Identifying information for 17,357 children of Iowa pesticide applicators was provided by parents via questionnaires (1993-1997) and matched against the Iowa Cancer Registry. Fifty incident childhood cancers were identified (1975-1998). Risk of all childhood cancers combined was increased [standardized incidence ratio (SIR) = 1.36; 95% confidence interval (CI), 1.03-1.79]. Risk of all lymphomas combined was also increased (SIR = 2.18; 95% CI, 1.13-4.19), as was risk of Hodgkin's lymphoma (SIR = 2.56; 95% CI, 1.06-6.14). We used logistic regression to explore associations between self-reported parental pesticide application practices and childhood cancer risk. No association was detected between frequency of parental pesticide application and childhood cancer risk. An increased risk of cancer was detected among children whose fathers did not use chemically resistant gloves [odds ratio (OR) = 1.98; 95% CI, 1.05-3.76] compared with children whose fathers used gloves. Of 16 specific pesticides used by fathers prenatally, ORs were increased for aldrin (OR = 2.66), dichlorvos (OR = 2.06), and ethyl dipropylthiocarbamate (OR = 1.91). However, these results were based on small numbers and not supported by prior biologic evidence. Identification of excess lymphoma risk suggests that farm exposures including pesticides may play a role in the etiology of childhood lymphoma.     

Hepatitis A shifting epidemiology in the Middle East and Africa

Data on the endemicity of hepatitis A virus (HAV) infection in Africa and the Middle East are scant, but most of Africa appears to remain a high endemicity region, with the exception of subpopulations in some areas, e.g. White people in South Africa. Saudi Arabia is a model for the Middle East, and is a country in which shifting HAV epidemiology has been documented in recent years, concurrent with the social and economic development that has occurred over the last two decades. Earlier studies generally showed very high prevalence rates, with most people becoming infected in early childhood. Between 1989 and 1995, however, there was a significant fall in the seroprevalence of antibodies to HAV in children up to 12 years old throughout the country except in one region bordering the Yemen. The highest seroprevalence is found in children from rural backgrounds, while the seroprevalences in Bedouin and urban children are similar. Seroprevalence is related to socioeconomic status, being highest in the lowest groups. Similar findings have been reported from other countries in the Middle East. The existence of pockets of high endemicity for HAV infection with surrounding areas shifting towards intermediate endemicity may lead to outbreaks, and widespread vaccination should be considered.     

Smoking and lymphoma risk in the European prospective investigation into cancer and nutrition

Lymphomas are one of the few cancers that have been increasing in incidence over the past decades. So far, only a few established risk factors have been identified, including immunosuppression and viral infections. Recent evidence suggests etiologic heterogeneity of different lymphoma subtypes. Smoking may affect risk differently, depending on the lymphoma entity. The European Prospective Investigation into Cancer and Nutrition was used to study the role of smoking in the etiology of lymphomas and individual subtypes within a prospective study. Information on baseline and lifetime tobacco smoking by 478,590 participants was collected between 1992 and 2000. Cox proportional hazards regression was used to calculate multivariate-adjusted hazard ratios and 95% confidence intervals. During 3,567,410 person-years of follow-up, 1,371 lymphoma cases (1,304 non-Hodgkin's lymphomas and 67 Hodgkin's lymphomas) were identified. Relative risk for smokers at recruitment was more than twofold higher for Hodgkin's lymphoma (hazard ratio = 2.14, 95% confidence interval: 1.18, 3.87) but was not elevated for non-Hodgkin's lymphoma (hazard ratio = 1.06, 95% confidence interval: 0.94, 1.19) and individual B-cell non-Hodgkin's lymphoma subtypes. In this prospective study, smoking appeared to increase Hodgkin's lymphoma risk consistently in both genders, whereas B-cell non-Hodgkin's lymphoma risk was not associated. Future analysis should involve viral biomarkers and genetic susceptibility markers to elucidate potential mechanisms of smoking-induced carcinogenesis, particularly for Hodgkin's lymphoma.