Evaluation of childhood acute leukemia incidence and underreporting in Brazil by capture–recapture methodology

Acute lymphoid and myeloid leukemia in a Brazilian Amazon population: Epidemiology and predictors of comorbidity and deaths

Introduction

Leukemia is the most common cancer in children and has the highest rates of incidence in industrialized countries, followed by developing countries. This epidemiologic profile can mainly be attributed to the availability of diagnostic resources. In Brazil, leukemia diagnosis is a challenge due to financial viability, lack of hemovigilance services in isolated regions and the vast size of the territory. Its incidence in the state of Amazonas has been increasing since 2010. Therefore, this study aims to describe the epidemiological pattern and spatial distribution of patients with acute lymphoid leukemia and acute myeloid leukemia in Amazonas and identify the predictors of comorbidity and death.

Materials and methods

A retrospective cross-sectional study was carried out based on patients’ data which was obtained from the database of a referral center for the period of 2005 to 2015. Variables included age, gender, ethnicity, civil status, schooling, income, location of residence, subtype of leukemia, comorbidities, and date of death. The spatial distribution was performed using QGIS v.2.18. Stata software was used for univariable and multivariable logistic regression to evaluate the association between both comorbidities and death for all characteristic groups of ALL and AML.

Results

The group that was studied was composed of 577 ALL and 266 AML patients. For both, most patients were male, with a schooling period of 1–4 years, received<1 minimum wage, and lived mostly in Manaus, followed by the municipality of Tefé. There was no association between the development of comorbidities and analyzed variables in patients with ALL. AML patients that were >60 years old and with family history of the disease had the highest risk of developing comorbidities (OR = 5.06, p = 0.038; OR = 2.44, p = 0.041, respectively). Furthermore, patients with ALL and in the 41-50-year age group had a higher risk of death (OR = 31.12; p = 0.001). No association between death and explanatory variables were found in patients with AML. In addition, significant difference was observed in time to death (chi2 = 4,098.32, p = 0.000), with 50% of patients with AML dying within two years after diagnosis, whereas in ALL, this percentual of death only is reached in approximately 5 years.

Conclusion

Our study describes the data of patients with acute leukemia in Amazonas, a remote region in the north of Brazil. In addition, it highlights the importance of hemovigilance in an Amazon region state, while focusing on peripheral areas which don't have prevention, diagnosis and treatment tools for this disease.

Incidence of childhood cancer in Costa Rica, 2000-2014: An international perspective

BACKGROUND

Estimating childhood cancer incidence globally is hampered by a lack of reliable data from low- and middle-income countries. Costa Rica is one of the few middle-income countries (MIC) with a long-term high quality nationwide population-based cancer registry.

METHODS

Data on incident cancers in children aged under 15 years reported to the Costa Rica National Cancer Registry between 2000 and 2014 were analyzed by diagnostic group, age, sex, and geographical region and compared with incidence data for Hispanic and Non-Hispanic White (NHW) children in California, USA.

RESULTS

During the 15-year period, 2396 cases of childhood cancer were reported in Costa Rica, resulting in an overall age-standardized incidence rate (ASR) of 140/million. Most frequent cancer types were leukemias (40.5%), malignant central nervous system (CNS) tumors (13.9%), and lymphomas (12.7%). The observed ASR of lymphoid leukemia (46.9/million) ranked high globally. Low rates were found for most solid tumors including malignant CNS tumors, sympathetic nervous system tumors, and soft tissue sarcomas. There was almost no change in incidence rates over time, while geographical variations were observed within Costa Rica. The overall cancer rate in Costa Rica was lower compared to NHW (176.1/million) and Hispanic (161.7/million) children in California.

CONCLUSION

Based on the longstanding registration system, the childhood cancer incidence rates were similar to those observed in other Latin American countries. While a degree of under-ascertainment of cases cannot be excluded, the markedly high leukemia rates, in particular of the lymphoid sub-type deserves further study in this population.

Incidence and survival of childhood leukemia in Recife, Brazil: A population-based analysis

BACKGROUND

Leukemia is the most common pediatric cancer with incidence rates of around 48 per million for children under 15 years of age. The median age-adjusted incidence rate (AAIR) in children aged 0-14 years in Brazil is 53.3 per million. While overall survival rates for children with leukemia have improved significantly, data for incidence, trends, and relative survival among children and adolescents with leukemia in Recife, Brazil, remain incomplete, which hampers our analyses and provision of the best healthcare. The objective of this report is to provide that data.

METHODS

Data from the Population-Based Cancer Registry of Recife were analyzed from 1998 to 2007. Our analyses included frequencies and AAIR, together with age-specific incidence rates for all leukemias, acute lymphoblastic leukemia, and acute myeloid leukemia. To evaluate incidence trends, joinpoint regression, including annual average percent change, were analyzed. Relative survival was calculated using the life-table method.

RESULTS

One hundred seventy-five cases were identified, 51% in females. The review reduced the not otherwise specified (NOS) leukemia category by 50% and diagnosis by death certificate only from 5.7% to 1.1%. The AAIR for leukemia was 41.1 per million, with a peak among children aged 1-4 (78.3 per million). Incidence trends during the period were stable. The five-year relative survival rate was 69.8%.

CONCLUSIONS

These data represent the incidence rate and survival of childhood leukemia in Recife, located in the northeast region of Brazil, using a high-quality database.

Early childhood leukemia incidence trends in Brazil

Incidence rates of childhood leukemia vary between different regions of the world. The objective of this study was to test possible trends in incidence rate of early childhood leukemia (children <5 years old at the diagnosis) in Brazil. Data from 18 population-based cancer registries (PBCRs) were analyzed (period 1999-2010). The analysis consisted of frequencies, age-adjusted incidence rates, and joinpoint regression results, including annual average percent change (AAPC) in incidence rates and 95% confidence intervals (CIs). The median age-adjusted incidence rate (AAIR) of overall early childhood leukemia was 61 per million. The AAIR for acute lymphoid leukemia (ALL) was 44 per million and nonlymphoid acute leukemia (NLAL) was 14 per million. The median ALL/NLAL ratio was 3.0, suggesting higher incidence rate of NLAL in these settings. The joinpoint analysis demonstrated increased leukemia incidence rate in João Pessoa (AAPC = 20; 95% CI: 3.5, 39.4) and Salvador (AAPC = 8.68; 95% CI: 1.0, 16.9), respectively, whereas incidence rate in São Paulo PBCR decreased (AAPC = -4.02%; 95% CI: -6.1%, -1.9%). Correlation between ALL AAIR and selected variables of socioeconomic (SES) factors was not observed. Increased AAIR regionally overtime was observed. However, the interpretation for such phenomenon should be cautious because it might reflect the access to health care, diagnosis procedures, and improvement of PBCR´s quality. The observed trend supports the necessity of further ecological studies.

Epidemiology of childhood and adolescent cancer in Bangladesh, 2001-2014

BACKGROUND

Cancer burden among children and adolescents is largely unknown in Bangladesh. This study aims to provide a comprehensive overview on childhood and adolescent cancers and to contribute to the future strategies to deal with these diseases in Bangladesh.

METHODS

Data on malignant neoplasms in patients aged less than 20 years diagnosed between 2001 and 2014 (N = 3143) in Bangladesh was collected by the National Institute of Cancer Research and Hospital and ASHIC Foundation. The age pattern and distribution of cancer types were analysed and the incidence rates were calculated.

RESULTS

The age-standardised incidence rate was 7.8 per million person-years for children (0-14 years) in the last time period (2011-2014). Retinoblastoma (25%) and leukaemia (18%) were the most common childhood cancers. For adolescents (15-19 years), the age-specific incidence rate was 2.1 per million person-years in the same time period. Most common adolescent cancers were malignant bone tumours (38%), germ cell and gonadal tumours (17%), and epithelial tumours (16%). There were more boys affected (M: F ratio 2.0 in children and 1.4 in adolescents) than girls.

CONCLUSION

Cancer incidences were lower than expected most likely due to a low level of awareness about cancer among clinicians and the population, inadequate access to health care, lack of diagnostic equipment and incomplete recording of cases. Improvements on different levels should be made to get a better epidemiologic insight and to detect cancer earlier resulting in a better outcome for affected children and adolescents.

Estimation of Completeness of Cancer Registration for Patients Referred to Shiraz Selected Centers through a Two Source Capture Re-capture Method, 2009 Data

BACKGROUND

Cancer has important social consequences with cancer registration as the basis of moving towards prevention. The present study aimed to estimate the completeness of registration of the ten most common cancers in patients referred to selected hospitals in Shiraz, Iran by using capture-recapture method.

MATERIALS AND METHODS

This cross-sectional analytical study was performed in 2014 based on the data of 2009, on a total of 4,388 registered cancer patients. After cleaning data from two sources, using capture-recapture common findings were identified. Then, the percentage of the completeness of cancer registration was estimated using Chapman and Chao methods. Finally, the effects of demographic and treatment variables on the completeness of cancer registration were investigated.

RESULTS

The results showed that the percentages of completeness of cancer registration in the selected hospitals of Shiraz were 58.6% and 58.4%, and influenced by different variables. The age group between 40-49 years old was the highest represented and for the age group under 20 years old was the lowest for cancer registration. Breast cancer had the highest registration level and after that, thyroid and lung cancers, while colorectal cancer had the lowest registration level.

CONCLUSIONS

According to the results, the number of cancers registered was very few and it seems that factors like inadequate knowledge of some doctors, imprecise diagnosis about the types of cancer, incorrectly filled out medical documents, and lack of sufficient accuracy in recording data on the computer cause errors and defects in cancer registration. This suggests a necessity to educate and teach doctors and other medical workers about the methods of documenting information related to cancer and also conduct additional measures to improve the cancer registration system.

Childhood cancer incidence patterns by race, sex and age for 2000-2006: a report from the South African National Cancer Registry

Higher childhood cancer incidence rates are generally reported for high income countries although high quality information on descriptive patterns of childhood cancer incidence for low or middle income countries is limited, particularly in Sub-Saharan Africa. There is a need to quantify global differences by cancer types, and to investigate whether they reflect true incidence differences or can be attributed to under-diagnosis or under-reporting. For the first time, we describe childhood cancer data reported to the pathology report-based National Cancer Registry of South Africa in 2000-2006 and compare our results to incidence data from Germany, a high income country. The overall age-standardized incidence rate (ASR) for South Africa in 2000-2006 was 45.7 per million children. We observed substantial differences by cancer types within South Africa by racial group; ASRs tended to be 3-4-fold higher in South African Whites compared to Blacks. ASRs among both Black and White South Africans were generally lower than those from Germany with the greatest differences observed between the Black population in South Africa and Germany, although there was marked variation between cancer types. Age-specific rates were particularly low comparing South African Whites and Blacks with German infants. Overall, patterns across South African population groups and in comparison to Germans were similar for boys and girls. Genetic and environmental reasons may probably explain rather a small proportion of the observed differences. More research is needed to understand the extent to which under-ascertainment and under-diagnosis of childhood cancers drives differences in observed rates.

Assistencia ao cancer entre criancas e adolescentes: mapeamento dos fluxos origem-destino no Brasil

OBJETIVO: Analisar os fluxos de viagens de crianças e adolescentes com câncer, entre os locais de residência e serviço de saúde. MÉTODOS: Foram analisados os fluxos de viagens de crianças e adolescentes com câncer entre os locais de residência e de serviço de saúde atendidos no Sistema Único de Saúde (SUS), de 2000 a 2007. A unidade de análise foi a regional de saúde. Utilizou-se o sistema de informações geográficas e metodologia de redes por tipo de tratamento recebido (quimioterapia e radioterapia) e internações hospitalares. RESULTADOS: Foram emitidas 465.289 autorizações de quimioterapia, 29.151 de radioterapia e 383.568 de internações hospitalares de crianças e adolescentes com diagnóstico de câncer para tratamento no SUS. O fluxo dominante formou 48 redes para quimioterapia, 53 para radioterapia e 112 para internações hospitalares. A maior parte do volume de atendimento ocorreu nas regionais de saúde das 12 maiores metrópoles do País com grande relacionamento entre elas e extensa área de influência direta acompanhando a estrutura da rede urbana brasileira. CONCLUSÕES: A identificação das redes estabelecidas no âmbito do SUS para o atendimento de crianças e adolescentes com câncer mostra que a maioria dos pacientes está contemplada pelas redes estruturadas. Cerca de 10% das viagens ocorrem fora do fluxo dominante, indicando a necessidade de regionalização alternativa. Os resultados evidenciam a importância do planejamento da distribuição dos serviços de acordo com as necessidades da população usuária.

Inpatient electronic prescribing data can be used to identify 'lost' discharge codes for diabetes

AIM

Accurate assessment of missed discharge codes for diabetes is critical for effective planning of hospital diabetes services. We wished to estimate the frequency of missed discharge diagnostic codes for diabetes and the impact missed codes would have on diabetes-related payments to the hospital.

METHODS

We linked Patient Administration System data to the Prescribing Information and Communication System. We defined diabetes as those having a discharge code for diabetes in the Patient Administration System and those on anti-diabetic medication in the Prescribing Information and Communication System. Based on the two sources, we calculated the estimated missed discharge codes for diabetes using the capture-recapture technique. We generated the Healthcare Resource Group for a given admission before and after correction for the missed code to estimate the impact that correction would make on payments to the hospital.

RESULTS

Among the 171 067 admissions linked, 22 412 (13.1%) had a code for diabetes at discharge. An additional 2706 admissions were classified as having diabetes based on prescription data. The capture-recapture technique estimated there were 4588 (2.7% of all admissions) admissions with diabetes missed by current coding, of which 2706 (60%) would be obtained from prescription data. After adding a diabetes diagnostic code, 12.8% of the missed admissions with diabetes resulted in a change to the Healthcare Resource Group tariff code and payment.

CONCLUSION

The use of electronic prescription data is a simple solution to correct for missed discharge diagnostic codes.

Quality assessment of capture-recapture studies in resource-limited countries

OBJECTIVES

Resource-limited countries often lack robust routine surveillance systems to accurately assess the burden of human attributes and diseases. In these settings capture-recapture analysis can be an alternative tool to obtain prevalence and incidence rates. Performance of capture-recapture analyses in resource-limited countries has not been systematically reviewed.

METHODS

Systematic review of the performance of capture-recapture analyses in the categories of human attributes, non-infectious and infectious diseases in resource-limited countries, assessing individual study quality criteria and a minimum quality criterion per category, using PRISMA methodology.

RESULTS

A total of 1671 potentially relevant PubMed citations were screened, resulting in 52 eligible publications: 36% in human attributes, i.e. hidden populations, injuries and mortality; 48% in non-infectious and 15% in infectious disease categories. Twenty-one per cent of selected studies were from low income countries, 40% from lower-middle-income countries and 38% from upper-middle-income countries. Thirteen per cent achieved good individual study quality criteria, 25% were intermediate and 19% were poor. Of the good studies, six were performed on human attributes and one on a non-infectious disease. The proportions of publications meeting the minimum quality criterion per category were 42%, 20% and 37%, respectively.

CONCLUSIONS

Few capture-recapture studies in resource-limited countries achieved good individual quality criteria and a minority met the minimum quality criterion per category. Capture-recapture techniques in these settings should be carefully considered and implemented rigorously and are not a panacea for strengthening of routine surveillance systems.

Childhood cancer registration in Britain: capture-recapture estimates of completeness of ascertainment

Background:

Completeness of ascertainment is a very important aspect of cancer registration. There is no recent published estimate for childhood cancer in Britain.

Methods:

We estimated completeness of ascertainment by the National Registry of Childhood Tumours for cancer diagnosed under age 15 years in residents of Britain during 2003–04. Stratified two-source capture-recapture was applied to notifications from general cancer registries (CRs) and specialist clinicians. Variation in notification patterns was assessed by logistic regression. Results were verified by cross-checking with Hospital Episode Statistics for leukaemia patients from England born in 1998 and diagnosed before 2005.

Results:

CRs notified 92–96% of registrations, and specialist clinicians 93%. Notification patterns varied slightly according to registry region, age at diagnosis, diagnostic group, socioeconomic status, and whether the patient had died. Irrespective of stratification by these factors, the overall completeness estimate was 99–100% (assuming independence of sources). Estimated completeness was at least 99% within all subgroups, except for one region (Thames 98–99%) and two small diagnostic groups (germ-cell and gonadal cancer 98–99%, melanoma and non-skin cancer 97–98%).

Interpretation:

The independence assumption cannot be fully justified, as both sources used records from treatment centres. With this caveat, ascertainment of recently diagnosed childhood cancer in Britain appears to be virtually complete.

Childhood leukemia incidence in Brazil according to different geographical regions

BACKGROUND

Resource-rich countries tend to have a higher incidence of childhood acute lymphoblastic leukemia (ALL), whereas lower rates are seen in more deprived countries. This study describes the incidence of childhood acute leukemia in Brazil, an upper middle-income country, based on data from 16 population-based cancer registries (PBCRs).

PROCEDURE

Data were examined from 16 PBCRs in Brazilian cities located in five geographical regions during the period from 1997 to 2004. Incidence rates were analyzed according to gender, age, and type of leukemia. The Wilcoxon test was performed to evaluate for gender-age based difference between by leukemia type.

RESULTS

The median age-adjusted incidence rate (AAIR) of leukemia in children aged 0-14 years old was 53.3 per million. A different AAIR was found regarding ALL and myeloproliferative disorders (MPD) that ranged from 24.8 to 76.84 per 1,000,000 children. Manaus, although located in a poor area of Brazil, exhibited the highest AAIR (56.6 per million) of ALL. Goiania had the highest AAIR (24.5 per million) of MPD. The median age-specific incidence rate (ASIR) for the 16 Brazilian PBCRs demonstrated a marked peak in incidence of ALL at age 3 years old, in both genders.

CONCLUSIONS

This population-based study of childhood leukemia demonstrates that substantial regional differences exist regarding the incidence of acute leukemia in Brazil, which warrants further ecological study.

Implications of infectious diseases and the adrenal hypothesis for the etiology of childhood acute lymphoblastic leukemia

Acute leukemia is the most frequent cancer in children. Recently, a new hypothesis was proposed for the pathogenesis of childhood acute lymphoblastic leukemia (ALL). The so-called 'adrenal hypothesis' emphasized the role of endogenous cortisol in the etiology of B-cell precursor ALL. The incidence peak of ALL in children between 3 to 5 years of age has been well documented and is consistent with this view. The adrenal hypothesis proposes that the risk of childhood B-cell precursor ALL is reduced when early childhood infections induce qualitative and quantitative changes in the hypothalamus-pituitary-adrenal axis. It suggests that the increased plasma cortisol levels would be sufficient to eliminate all clonal leukemic cells originating during fetal life. Because Brazil is a continental and tropical country, the exposure to infections is diversified with endemic viral and regionally non-viral infections, with some characteristics that support the recent adrenal hypothesis. Here we discuss this new hypothesis in terms of data from epidemiological studies and the possible implications of the diversity of infections occurring in Brazilian children.

Pediatric lymphomas in Brazil

OBJECTIVE

This study provides the clinical pathological characteristics of 1301 cases of pediatric/adolescent lymphomas in patients from different geographic regions of Brazil.

METHODS

A retrospective analyses of diagnosed pediatric lymphoma cases in a 10-year period was performed. We believe that it represents the largest series of pediatric lymphomas presented from Brazil.

RESULTS

Non-Hodgkin lymphomas represented 68% of the cases, including those of precursor (36%) and mature (64%) cell origin. Mature cell lymphomas comprised 81% of the B-cell phenotype and 19% of the T-cell phenotype. Hodgkin lymphomas represented 32% of all cases, including 87% of the classical type and 13% of nodular lymphocyte predominant type. The geographic distribution showed 38.4% of the cases in the Southeast region, 28.7% in the Northeast, 16.1% in the South, 8.8% in the North, and 8% in the Central-west region. The distribution by age groups was 15-18 years old, 33%; 11-14 years old, 26%; 6-10 years old, 24%; and 6 years old or younger, 17%. Among mature B-cell lymphomas, most of the cases were Burkitt lymphomas (65%), followed by diffuse large B-cell lymphomas (24%). In the mature T-cell group, anaplastic large cell lymphoma, ALK-positive was the most prevalent (57%), followed by peripheral T-cell lymphoma, then not otherwise specified (25%). In the group of classic Hodgkin lymphomas, the main histological subtype was nodular sclerosis (76%). Nodular lymphocyte predominance occurred more frequently than in other series.

CONCLUSION

Some of the results found in this study may reflect the heterogeneous socioeconomical status and environmental factors of the Brazilian population in different regions.