Trends in Childhood Cancer Incidence and Mortality in Catalonia, Spain, 1975–1998

Childhood central nervous system tumour mortality and survival in Southern and Eastern Europe (1983-2014): Gaps persist across 14 cancer registries

AIM

Childhood central nervous system (CNS) tumour registration and control programs in Southern and Eastern Europe remain thin, despite the lethal nature of the disease. Mortality/survival data were assembled to estimate the burden of malignant CNS tumours, as well as the potential role of sociodemographic survival determinants across 14 cancer registries of this region.

METHODS

Average age-adjusted mortality rates were calculated, whereas time trends were quantified through Poisson and Joinpoint regressions. Kaplan-Meier curves were derived for the maximum and the more recent (10 and 5 year) registration periods. Multivariate Cox regression models were used to assess demographic and disease-related determinants.

RESULTS

Variations in mortality (8-16 per million) and survival (5-year: 35-69%) were substantial among the participating registries; in most registries mortality trend was stable, whereas Bulgaria, having the highest starting rate, experienced decreasing annual mortality (-2.4%, p=0.001). A steep decrease in survival rates was evident before the second year of follow-up. After controlling for diagnostic subgroup, age, gender and diagnostic year, Greece seemed to present higher survival compared with the other contributing registries, although the follow-up period was short. Irrespective of country, however, rural residence was found to impose substantial adverse repercussions on survival (hazard ratio (HR): 1.2, 95% confidence interval (CI): 1.1-1.4).

CONCLUSION

Cross-country mortality and survival variations possibly reflect suboptimal levels of health care delivery and cancer control in some regions of Southern and Eastern Europe, notwithstanding questionable death certification patterns or follow-up procedures. Continuous childhood cancer registration and linkage with clinical data are prerequisite for the reduction of survival inequalities across Europe.

Registration of childhood cancer: Moving towards pan-European coverage?

Cancer is relatively rare in childhood, but it contributes considerably to childhood mortality, years of life lost per person and late effects in survivors. Large populations need to be covered to set up meaningful studies of these rare conditions. Cancer registries ensure cancer surveillance, thus providing the basis for research as well as policy decisions. In this paper we examine coverage of childhood population by cancer registries in Europe and encourage national cancer registration. Over 200 cancer registries in various stages of development were identified as collecting data on childhood cancer patients in Europe. They cover 52% of the childhood population in the World Health Organisation (WHO) European region and 83% in the European Union (EU). More than 80% of this coverage is ensured by nationwide data collection, which is ongoing in 29 European countries. Overall coverage of the childhood population could increase to around 98%, if the recently established cancer registries start producing results and others improve their quality and dissemination plans. Paediatric cancer registries are being established with increasing frequency even in the areas covered by general cancer registries, and they tend to be national. Compared with regional registration, national cancer registries are more cost-effective, record larger number of cases, they can achieve higher completeness, less biased incidence and survival estimates and they are conditioned for national and international research. National registration of childhood cancer should be the rule in Europe, so that accurate regional, nation-wide and international statistics can provide solid baselines for research, clinical practice and public health policy. Governmental support and stakeholders' involvement are indispensable to guarantee optimal data quality and completeness.

Pattern of childhood cancer in University College Hospital, Ibadan during 1991-2010 and comparison with the previous three decades

BACKGROUND

Cancer is an important cause of morbidity and mortality worldwide in children under 15 years of age, with the incidence and mortality rate varying from 40 to 155 per million children.

AIM

To describe the pattern of childhood cancer in Ibadan, Nigeria.

OBJECTIVE

To compare the findings of this study with those of previous studies in Ibadan and internationally.

METHODS

A retrospective review of histologically and cytologically confirmed cases of cancer in children aged <15 years diagnosed at University College Hospital (UCH), Ibadan between January 1991 and December 2010 was undertaken. The cases were categorised using the International Classification of Childhood Cancer, third edition (ICCC-3).

RESULTS

There were 625 cases comprising 360 (57·6%) males with a modal age of 3 years. The most common neoplasms were lymphomas (140, 22·4%), of which 90% were non-Hodgkin lymphomas, with Burkitt lymphoma constituting the majority of cases (73). Other common neoplasms were retinoblastomas (21%), soft tissue sarcomas (14·9%), leukaemias (10·2%) and CNS tumours (6·9%). Lymphomas, bone tumours, malignant hepatic tumours and other malignant epithelial neoplasms had the highest mean and modal ages, while retinoblastomas, neuroblastomas, germ cell tumours and renal tumours had the lowest mean and modal ages. During 1960-72 there were 1326 cases and during 1973-90 there were 1881 cases and the proportion of lymphomas was 58·9% and 45·4%, respectively. The present study demonstrated a marked decline in the number of cases and proportion of lymphomas (22·4%), particularly Burkitt lymphomas.

CONCLUSION

During the last 20 years, there has been a decline in the number of cases of childhood cancer seen at UCH, Ibadan. This may be due to the establishment of additional specialist centres in the sub-region. Owing to a persistent decline in the frequency of Burkitt lymphoma, retinoblastoma is now the most common individual childhood cancer seen at Ibadan.

Cancer in childhood, adolescence, and young adults: a population-based study of changes in risk of cancer death during four decades in Norway

PURPOSE

Cancer is one of the most common causes of death among young individuals. The purpose of this study was to explore the risk of early death (the first five years after diagnosis) among children (0-14 years), adolescents (15-19 years), and young adults (20-24 years) with cancer in Norway, born during 1965-1985.

METHODS

The overall and cancer-specific early deaths were explored by linking population-based national registers (including the Cancer Registry of Norway and the Cause of Death Registry) that include the entire population of Norway (approximately 1.3 million individuals). Hazard and sub-hazard ratios were estimated using Cox regression analyses and competing risk models.

RESULTS

A total of 5,828 individuals were diagnosed with cancer (56.3 % males). During follow-up, 1,415 individuals died from cancer (60.2 % males) within five years after diagnosis. The hazard ratio (HR) of overall death of the cancer patients relative to the general population decreased from 1965 (from HR, 385.8 (95 % confidence interval (CI): 335.3, 443.4) in 1965-74 to HR, 19.7 (CI: 9.3, 41.5) in 2005-09). Over all, there were fewer cancer-related deaths among female compared with male patients (sub-hazard ratio (SHR), 0.83 (CI: 0.74, 0.92)). Except for all hematopoietic malignancies, adolescents and young adult patients had lower risk of cancer death than children.

CONCLUSION

The difference in risk of cancer and overall deaths between the cancer patients and the general population has been substantially reduced since 1965.

Trends in childhood cancer incidence and mortality in urban Shanghai, 1973-2005

BACKGROUND

To describe trends in cancer incidence and mortality among children less than 15 years of age in urban Shanghai between 1973 and 2005.

PROCEDURE

Annual rates of cancer incidence were calculated per 1,000,000 children for 3-year intervals between 1973 and 2005. Linear regression models were used to analyze the annual percent change (APC) in incidence and mortality across these distinct intervals.

RESULTS

For all cancers combined, the incidence rate during the observed time period did not substantially change in urban Shanghai. Rates for the incidence of individual cancer did exhibit variations. Leukemia incidence remained relatively stable but the incidence of myeloid leukemia decreased sharply in both males (APC -8.6%) and females (APC -9.5%). The rate of NHL varied little among males with APC 2.1% and modestly increased among females with APC 9.3%. Anatomic sites that only occasionally demonstrate malignancy, bone and joints in males and endocrines in females, showed upward trends in incidence. A significant reduction in liver cancer incidence in males was observed. Examining mortality rates, all cancer mortality decreased by -6.0% annually in males and by -3.9% in females. This trend was mainly due to the reduction in mortality for leukemia, particularly the myeloid subtype, which decreased in males (APC -7.2%) and females (APC -7.3%).

CONCLUSIONS

Childhood cancer incidence rates showed no substantial changes but mortality demonstrated a dramatic reduction during the observed time period, suggesting an improvement in both childhood cancer diagnosis and treatment.

[Presenting signs and symptoms of central nervous system tumors according to age]

INTRODUCTION

Central nervous system tumors are the second most frequent group of neoplasms in children and are the main cause of cancer-related deaths in the pediatric population. There are no specific clinical findings. Consequently clinical data that would aid diagnosis are required.

OBJECTIVE

To establish the presenting signs and symptoms of brain tumors in childhood according to age and identify their influence on diagnostic delay.

PATIENTS AND METHODS

We retrospectively studied 69 patients with central nervous system tumors diagnosed between January 1997 and December 2002 in the Virgen del Rocío children's hospital.

RESULTS

At diagnosis, 60.9 % of the patients were in the most advanced clinical stages. The most commonly found signs were papilledema, ataxia and squint, with no differences among age groups. The most frequent symptoms were vomiting, headache and behavior changes (irritability in children aged less than 5 years and unhappiness in children aged more than 5 years). Diagnostic delay was longer in older children.

CONCLUSIONS

The diagnostic signs and symptoms of central nervous tumors are non-specific. A high index of suspicion is required for early diagnosis.

Increasing incidence of childhood tumours of the central nervous system in Denmark, 1980-1996

The registered incidence rate of childhood central nervous system (CNS) tumours has increased in several countries. It is uncertain whether these increases are biologically real or owing to improved diagnostic methods. We explored the medical records of 626 CNS tumours diagnosed in Danish children between 1980 and 1996. Population-based registers were used to extract data on mortality and background population. Temporal patterns were analysed by regression techniques. Most tumours were verified by computed tomography (78%) or magnetic resonance imaging (14%). Overall, the incidence rate increased by 2.9% per year (95% confidence interval (CI): 1.3;4.5) and the mortality rate increased by 1.4% per year (95% CI: −0.4;3.3). Among children aged 0–4 years, the survival rate after diagnosis remained almost unchanged, whereas among children aged 5–14 years, the 10-year survival rate improved from 59 to 74%. These data suggest that the incidence rate of CNS tumours among Danish children has truly increased, although alternative explanations cannot be excluded.

Bayesian methods for early detection of changes in childhood cancer incidence: Trends for acute lymphoblastic leukaemia are consistent with an infectious aetiology

Published data on time trends in the incidence of childhood leukaemia show inconsistent patterns, with some studies showing increases and others showing relatively stable incidence rates. Data on time trends in childhood cancer incidence from the Childhood Cancer Registry of Piedmont, Italy were analysed using two different approaches: standard Poisson regression and a Bayesian regression approach including an autoregressive component. Our focus was on acute lymphoblastic leukaemia (ALL), since this is hypothesised to have an infectious aetiology, but for purposes of comparison we also conducted similar analyses for selected other childhood cancer sites (acute non-lymphoblastic leukaemia (AnLL), central nervous system (CNS) tumours and neuroblastoma (NB)). The two models fitted the data equally well, but led to different interpretations of the time trends. The first produced ever-increasing rates, while the latter produced non-monotonic patterns, particularly for ALL, which showed evidence of a cyclical pattern. The Bayesian analysis produced findings that are consistent with the hypothesis of an infectious aetiology for ALL, but not for AnLL or for solid tumours (CNS and NB). Although sudden changes in time trends should be interpreted with caution, the results of the Bayesian approach are consistent with current knowledge of the natural history of childhood ALL, including a short latency time and the postulated infectious aetiology of the disease.

Mortalidad por cáncer en niños y adolescentes de la Comunidad de Madrid, 1977-2001

INTRODUCTION

In the last few decades mortality from cancer among children and adolescents has not decreased homogeneously in industrialized countries. The aim of this study was to determine the epidemiological pattern and temporal trend of mortality from cancer in individuals aged less than 20 years old living in the Autonomous Community of Madrid from 1977 to 2001.

MATERIAL AND METHODS

Data on deaths from cancer among children and adolescents were obtained from Spain's National Institute of Statistics and from the Mortality Registry of Madrid. Populations were obtained from official publications of the Institute of Statistics of Madrid. Variables analyzed were sex, 5-year age groups, 5-year death periods and underlying cause of death. The epidemiological pattern was studied and a Poisson's regression model was used to analyze cancer mortality trends in children and adolescents from 1977 to 2001.

RESULTS

Cancer mortality among children and adolescents decreased by 41 % from 1977 to 2001. The decrease in mortality differed according to sex (46 % in boys and 33 % in girls) and type of cancer (leukemias: 38 %, non-Hodgkin's lymphomas: 58 %, malignant brain tumors: 45 %, malignant bone tumors: 19 %, ill-defined malignant tumors: 78 %). Moreover, the annual decrease was much greater in the last 5 years (4. 7 %) than during the entire period (2. 2 %).

CONCLUSIONS

Cancer mortality among children and adolescents decreased between 1977 and 2001 and our results are similar to those observed in other European and North American regions. To improve knowledge of the epidemiology of cancer among children and adolescents in the Autonomous Community of Madrid, future assessments including mortality, incidence, and survival indicators are required.

An infectious aetiology for childhood acute leukaemia: a review of the evidence

There are three current hypotheses concerning infectious mechanisms in the aetiology of childhood leukaemia: exposure in utero or around the time of birth, delayed exposure beyond the first year of life to common infections and unusual population mixing. No specific virus has been definitively linked with childhood leukaemia and there is no evidence to date of viral genomic inclusions within leukaemic cells. The case-control and cohort studies have revealed equivocal results. Maternal infection during pregnancy has been linked with increased risk whilst breast feeding and day care attendance in the first year of life appear to be protective. There is inconclusive evidence from studies on early childhood infectious exposures, vaccination and social mixing. Some supportive evidence for an infectious aetiology is provided by the findings of space-time clustering and seasonal variation. Spatial clustering suggests that higher incidence is confined to specific areas with increased levels of population mixing, particularly in previously isolated populations. Ecological studies have also shown excess incidence with higher population mixing. The marked childhood peak in resource-rich countries and an increased incidence of the childhood peak in acute lymphoblastic leukaemia (ALL) (occurring at ages 2-6 years predominantly with precursor B-cell ALL) is supportive of the concept that reduced early infection may play a role. Genetically determined individual response to infection may be critical in the proliferation of preleukaemic clones as evidenced by the human leucocyte antigen class II polymorphic variant association with precursor B-cell and T-cell ALL.