A geographical study of thyroid cancer incidence in north-west England following the Windscale nuclear reactor fire of 1957.

The Windscale nuclear reactor fire at Sellafield, United Kingdom, in October 1957 led to an uncontrolled release of iodine-131 (radioactive half-life, 8 d) into the atmosphere. Contamination from the accident was most pronounced in the counties of Cumbria and Lancashire, north-west England. Radioiodine concentrates in the thyroid gland producing an excess risk of thyroid cancer, notably among those exposed as children, which persists into later life. For an initial investigation of thyroid cancer incidence in north-west England, data were obtained on cases of thyroid cancer among people born during 1929-1973 and diagnosed during 1974-2012 while resident in England, together with corresponding populations. Incidence rate ratios (IRRs), with Poisson 95% confidence intervals (CIs), compared thyroid cancer incidence rates in Cumbria and in Lancashire with those in the rest of England. For those aged <20 years in 1958, a statistically significantly increased IRR was found for those diagnosed during 1974-2012 while living in Cumbria (IRR = 1.29; 95% CI 1.09-1.52), but the equivalent IRR for Lancashire was marginally non-significantly decreased (IRR = 0.91; 95% CI 0.80-1.04). This pattern of IRRs was also apparent for earlier births, and the significantly increased IRR in Cumbria extended to individuals born in 1959-1963, who would not have been exposed to iodine-131 from the Windscale accident. Moreover, significant overdispersion was present in the temporal distributions of the IRRs, so that Poisson CIs substantially underestimate statistical uncertainties. Consequently, although further investigations are required to properly understand the unusual patterns of thyroid cancer IRRs in Cumbria and Lancashire, the results of this preliminary study are not consistent with an effect of exposure to iodine-131 from the Windscale accident.

The androgen receptor gene CAG repeat in relation to 4-year changes in androgen-sensitive endpoints in community-dwelling older European men.

CONTEXT: The androgen receptor (AR) gene exon 1 CAG repeat length has been proposed to be a determinant of between-individual variations in androgen action in target tissues, which might regulate phenotypic differences of human ageing. However, findings on its phenotypic effects are inconclusive. OBJECTIVE: To assess whether the AR CAG repeat length is associated with longitudinal changes in endpoints that are influenced by testosterone (T) levels in middle-aged and elderly European men. DESIGN: Multinational European observational prospective cohort study. PARTICIPANTS: A total of 1887 men (mean ± s.d. age: 63 ± 11 years; median follow up: 4.3 years) from centres of eight European countries comprised the analysis sample after exclusion of those with diagnosed diseases of the hypothalamic-pituitary-testicular (HPT) axis. MAIN OUTCOME MEASURES: Longitudinal associations between the AR CAG repeat and changes in androgen-sensitive endpoints (ASEs) and medical conditions were assessed using regression analysis adjusting for age and centre. The AR CAG repeat length was treated as both a continuous and a categorical (6-20; 21-23; 24-39 repeats) predictor. Additional analysis investigated whether results were independent of baseline T or oestradiol (E2) levels. RESULTS: The AR CAG repeat, when used as a continuous or a categorical predictor, was not associated with longitudinal changes in ASEs or medical conditions after adjustments. These results were independent of T and E2 levels. CONCLUSION: Within a 4-year time frame, variations in the AR CAG repeat do not contribute to the rate of phenotypic ageing, over and above, which might be associated with the age-related decline in T levels.

UK case control study of brain tumours in children, teenagers and young adults: a pilot study.

BACKGROUND: Tumours of the central nervous system are the second most common group of childhood cancers in 0-14 year olds (24% of total cancers) and represent a major diagnostic group in 15-24 year olds. The pilot case-control study aimed to establish methodologies for a future comprehensive aetiological investigation among children and young adults. METHODS: Eligible cases were newly diagnosed with an intracranial tumour of neuroepithelial tissue aged 0-24 years. The pilot recruited patients through Leeds and Manchester Principal Treatment Centres. Controls were drawn from general practice lists. Controls were frequency matched by age and gender. RESULTS: We interviewed 49 cases and 78 controls comprising 85% of the target sample size. Response rates were 52% for cases and 32% for controls. Completion of the questionnaire was successful, with a very small proportion of missing data being reported (5-10%). The age distribution of cases and controls was similar with around three-quarters of interviewed subjects aged 0-14. Half of cases and almost two-thirds of controls reported using a mobile phone with the majority starting between 10-14 years of age. Prevalence of breastfeeding was lower in cases than controls (Odds Ratio 0.4; 95% CI 0.2-1.2), whilst cases were more likely to be delivered by caesarean section (OR 1.6; 95% CI 0.6-4.4). Cases were significantly more likely to have a birthweight > 3.5 kg compared to controls. Cases were also more likely to come from a family with 3 or more siblings than controls (OR 3.0; 95% CI 0.7-13.6). The majority of participants (>80%) were in favour of taking either blood or saliva to aid molecular epidemiological research. CONCLUSIONS: Successful methods were established for identifying and recruiting a high proportion of case subjects, exploiting strong links with the clinical teams at the treatment centres. Control procedures proved more difficult to implement. However, working closely with national clinical and professional research networks will enable improved control identification and recruitment, with good prospects for collecting biological samples in the future.

Median percent change: a robust alternative for assessing temporal trends.

A typical summary statistic for temporal trends is the average percent change (APC). The APC is estimated by using a generalized linear model, usually under the assumption of linearity on the logarithmic scale. A serious limitation of least-squares type estimators is their sensitivity to outliers. The goal of this study is twofold: firstly, we propose a robust and easy-to-compute measure of the temporal trend based on the median of the rates (median percent change - MPC), rather than their mean, under the hypothesis of constant relative change; secondly, we investigate the performance of several models for estimating the rate of change when some of the most common model assumptions are violated. We provide some guidance on the practices of the estimation of temporal trends when using different models under different circumstances. The robustness property of the median is assessed in a simulation study, which shows that the MPC provides strong reductions in estimation bias and variance in presence of outliers. We also demonstrate how a mathematical property of the median helps addressing the issue of zero counts when estimating trends on the log-scale. Finally, we analyzed an English cancer registration dataset to illustrate the proposed method. We believe that, as a good practice, both APC and MPC should be presented when sensitivity issues arise.

A survey of procedural sedation and analgesia practices in pediatric oncology centers in India.

OBJECTIVE: Repeated lumbar punctures (LP) and bone marrow aspirations (BMA) are part of childhood cancer management. Adequate sedation and analgesia for these procedures in a safe environment is desirable. We evaluate current practice related to this in pediatric oncology centers in India. METHODS: Clinicians attending the 2nd Annual India Pediatric Oncology Initiative meeting at New Delhi in February 2010 were invited to complete a questionnaire. Questionnaires were also sent by email to the remaining major pediatric oncology centers not represented at the meeting. Responses for LP and BMA were separately collated and variability by type of hospital and patient caseload was assessed. RESULTS: Responses were obtained from 26 of 32 centers (81%) approached. A median of 3 personnel (mostly pediatric residents and nurses) were present during the procedures. Some form of sedation and analgesia was used for LP and BMA in 88.5% and 100% centers respectively. However, use of systemic sedation and analgesia (usually midazolam +/- ketamine) for LP and BMA in ≥75% patients was seen in 47.8% and 61.6% centers respectively. General anesthesia was not used in any center. Additional restraint was commonly used and its use was significantly more in public hospitals (p = 0.01). Monitoring was usually done by observation of vital signs, with use of pulse-oximetry in less than half of the centers. CONCLUSIONS: There is varied use of sedation and analgesia for LP and BMA in pediatric oncology centers in India. Further research is needed to identify the reasons for this. Availability of resources is likely to be a factor.

Comparative incidence patterns and trends of gonadal and extragonadal germ cell tumors in England, 1979 to 2003.

BACKGROUND: It is believed that gonadal and extragonadal germ cell tumors (GCTs) arise from primordial germ cells and may have similar etiopathogenesis. Unlike testicular GCTs, there has been limited comprehensive population-based analysis of ovarian and extragonadal GCTs. METHODS: All malignant GCTs and all central nervous system (CNS) GCTs with benign and uncertain behavior that were registered in England in the age group 0 to 84 years from 1979 to 2003 were included in the current study. Incidence rates were calculated and adjusted to the world standard population. RESULTS: There were 33,364 GCTs (92.5% testes, 3.9% ovary, 3.2% extragonadal) in individuals aged 0 to 84 years. The CNS was the most common extragonadal site. An initial peak in incidence at ages 0 to 4 years of nongerminomas was observed at all sites except ovary. Second incidence peaks between ages 10 to 39 years that were more marked among males also were observed at all sites. The ages at these incidence peaks varied by site and were 10 to 14 years (CNS), 15 to 19 years (ovary), 25 to 29 years (other extragonadal sites), and 30 to 34 years (testes). A statistically significant increase in incidence over time was observed in germinomas (testes, CNS) and nongerminomas (testes, ovary). CONCLUSIONS: The age-incidence patterns observed suggested a common initiation of GCTs in embryonic/fetal life with variable rates of tumor progression as a result of subsequent events that may be site specific. The authors concluded that future genetic studies should consider GCTs from all sites to enable a better understanding of their etiology.

The contrasting age-incidence patterns of bone tumours in teenagers and young adults: Implications for aetiology.

Bone tumours comprise 0.2% of cancers overall but 5.7% in 15-24 year olds. To explore the relationship with adolescence we have analysed age-incidence patterns of bone tumours in a large national dataset. Data on incident cases of bone tumours in 0-84 year olds in England, 1979-2003, were extracted from national cancer registration data. Incidence rates per million person-years by 5-year age-group, sex, morphology and primary site were calculated and adjusted to the world standard population. Nine thousand one hundred forty-six cases were identified giving an overall age-standardized rate of 7.19 per million person-years. The distribution by morphology was: osteosarcoma, 34.2%; chondrosarcoma, 27.2%; Ewing sarcoma, 19.3%; other, 19.4%. The distribution varied by age. Ewing sarcoma was most common in 0-9 year olds, osteosarcoma in 10-29 year olds and chondrosarcoma in 30-84 year olds. 29.2% of all tumours occurred in 0-24 year olds. Highest incidence of osteosarcoma and Ewing sarcoma in females was in 10-14 year olds. In males, peak incidence occurred at 15-19 years and exceeded that in females. Chondrosarcoma incidence steadily increased with age. The proportions of Ewing sarcomas occurring in respective bones were consistent with those of the adult skeleton by weight. In osteosarcoma tumours of long bones of lower limb were markedly over-represented in the adolescent peak, being six times more than at any other site. Variation in incidence patterns with age and site suggests pubertal bone growth to be a key factor in osteosarcoma while different biological pathways could be relevant for Ewing sarcoma.

Cancer at ages 15-29 years: the contrasting incidence in India and England.

BACKGROUND: There has been a steady increase in published research from Europe and North America on the epidemiology of cancers in young people. There are limited data from the developing world. We contrast the incidence of cancer at ages 15-29 years in India and England. PROCEDURE: Malignant neoplasms in those aged 15-29 years registered during 2001-2003 in five urban population-based cancer registries (PBCRs) of India and in eight PBCRs in England were included. Site-based classification was used. Age-standardized incidence rates were expressed per 100,000 person years. RESULTS: In India, 4,864 (5.8%) of 84,450 cases and in England, 8,137 (1.2%) of 65,6752 cancer cases occurred in those aged 15-29 years. For this age group, the incidence rate for males and females in India were 12.91 and 14.19, and in England were 27.75 and 28.88, respectively. In males aged 15-29 years, the three most common cancers in India were leukemia, lymphoma, and central nervous system tumors and in England were cancers of male genital organs, lymphoma, and leukemia. Cancers of female genital organs, breast, and leukemia were most common in females in India and cancers of female genital organs, lymphoma, and melanoma in England. For cancers of mouth, stomach, and gall bladder, the incidence was higher in India. CONCLUSION: Incidence of cancer at ages 15-29 years in England is higher at most sites than in India. Variation in environmental exposures between the two countries might be an explanation. Under-ascertainment of cases and gender bias in seeking healthcare may also influence reported incidence rates in India.

Relationship between height at diagnosis and bone tumours in young people: a meta-analysis.

OBJECTIVE: Some evidence exists that patients with osteosarcoma and Ewing sarcoma are taller than the general population. However, previous studies are under-powered, lack comprehensive data and show inconsistencies. METHODS: Relevant studies linking osteosarcoma and Ewing sarcoma with height at diagnosis were identified in two major online databases, Medline (1950 to 2009) and Embase (1980 to 2009). Outcomes in individual studies were reported as standard deviation (SD) scores or percentages of study population with height at diagnosis above the median of the reference population. We performed separate random-effects meta-analyses for each outcome and tumour type. RESULTS: 14 studies examined the height of patients with osteosarcoma or Ewing sarcoma. Meta-analyses on SD scores found patients with osteosarcoma were 0.260 SD (95% CI: 0.088-0.432) taller than the reference population (five studies). A meta-analysis on percentages found 62% (95% CI: 57%-67%) of patients were estimated to have a height above the median (six studies). Patients with Ewing sarcoma were 0.096 SD (95% CI 0.004-0.188) taller (four studies). Only one study reported the percentage of Ewing sarcoma patients with height above the median. CONCLUSION: The average height of patients with osteosarcoma, but not Ewing sarcoma, was significantly above the average height of the reference population by 2-3 centimetres. The observed differences indicate the involvement of pubertal longitudinal bone growth in osteosarcoma development while different biological pathways could be relevant for Ewing sarcoma.

Are reported increases in incidence of primary CNS tumours real? An analysis of longitudinal trends in England, 1979-2003.

Reported increases in the incidence of CNS tumours in the developed world in the 1970s to 1990s have been a cause for concern and debate. It still remains to be adequately answered whether these increases are true or an artefact of changes in diagnostic and registration practices. Using high-quality national cancer registration data, we have analysed incidence trends for each major histological subgroup of CNS tumour (2000 World Health Organisation (WHO) classification) registered in those aged 0-84 years for the whole of England during the period 1979 through 2003. 134,509 primary CNS tumours of malignant, benign and uncertain behaviour located in the brain, meninges, spinal cord, cranial nerves, other parts of the central nervous system and in the pituitary and pineal glands were registered. In summary, we present the single largest nationwide study on the longitudinal incidence trends of CNS tumours. The increase in incidence observed in the 1970s and 1980s was mainly in the young and the elderly and has now plateaued and may even be decreasing. There is however variation in trends by histology. The incidence of some histological sub-groups has continued to increase until the most recent period of analysis. Much of the initial increase can be attributed to the emergence of much more widely available neuroimaging, while the most recent incidence changes for specific sub-groups of CNS tumours appear to be due to greater diagnostic specificity leading to a shift in registered categories. However, the trends for high-grade astrocytomas and other gliomas need further observation and investigation.

Age-incidence patterns of primary CNS tumors in children, adolescents, and adults in England.

Around 25% of all tumors in those 0-14 years of age and 9% in those 15-24 years of age involve the CNS. They are the most common cause of cancer-related deaths in both age groups. In adults 25-84 years of age, the proportion of CNS tumors is 2%; 5-year overall survival is 10%-15%; and survivors have considerable morbidity. Comprehensive up-to-date population-based incidence data on these tumors are lacking. We present incidence rates for primary CNS tumors based on data derived from the high-quality national cancer registration system in England. A total of 54,336 CNS tumors of malignant, benign, and uncertain behavior were registered across the whole of England from 1995 through 2003. The age-standardized rates for all ages (0-84 years) was 9.21 per 100,000 person-years. This is higher than previously reported for England because it includes nonmalignant CNS tumors and hence gives a more accurate picture of burden of disease. The age-standardized rates for those 0-14 years of age, 15-24 years of age, and 25-84 years of age were 3.56, 3.26, and 14.57 per 100,000 person-years, respectively. In this article, we describe the changing patterns in the epidemiology of primary CNS tumors in these three age groups with respect to sex, tumor behavior, and histology using the current WHO classification. This information will provide a reference for future studies nationally and internationally and make comparisons relevant and meaningful.

Changes in cancer incidence in teenagers and young adults (ages 13 to 24 years) in England 1979-2003.

BACKGROUND: Cancer for teenagers and young adults represents a major source of morbidity and mortality. Trends in cancer incidence can provide pointers concerning how changes in the environment and in personal behavior affect cancer risks. METHODS: Data on 39,129 neoplasms in individuals ages 13 to 24 years who were diagnosed in England from 1979 to 2003 were analyzed. Variability in incidence by time period and differences in the time trends by age group, sex, and geographic region were analyzed using generalized linear models. RESULTS: Incidence rates of leukemias, lymphomas, central nervous system, bone, and germ cell tumors; melanoma; and carcinomas of the thyroid, ovary, cervix, and colon/rectum increased over time (all P < .01); whereas the incidence of carcinomas of the stomach and bladder decreased (both P < .01). These changes were consistent by age, sex, and region for most neoplasms. Melanoma incidence stabilized in southern England by 1993 but continued to increase in northern England (P = .001). The increase in non-Hodgkin lymphoma was greater in individuals ages 20 to 24 year than in younger individuals, but the increase in Hodgkin lymphoma was confined to individuals ages 13 to 14 years. CONCLUSIONS: The changes in incidence rates may have been caused in part by environmental changes and in part by behavioral changes in young individuals. Some of these results can be used to inform public health campaigns, which can be constructed to encourage better lifestyle choices by young individuals.

Cancer risks among relatives of children with Hodgkin and non-Hodgkin lymphoma.

A role for genetic susceptibility in the aetiology of childhood lymphomas was investigated in 454 families of children with histologically confirmed Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) from Northwest England. Cancers in parents were obtained from the UK National Health Service Central Register and in other close relatives by interview with the parents. The cancer incidence among relatives was compared with expected incidence based on cancer registry data for England. There were 197 cancers in relatives (SIR 1.0 95% CI 0.8-1.1). In families of children with HL, there was an excess of HL in the first degree relatives (SIR 5.8 95% CI 1.2-16.9). Excesses of HL diagnosed under population median age (SIR 4.1 95% CI 1.1-10.6) were seen among all relatives and relatives of children who were below the median age at diagnosis (SIR 5.5 95% CI 1.1-16.0). In families of children with NHL, there were non-significant excesses of central nervous system (CNS) tumours in the first degree relatives (SIR 2.9 95% CI 0.8-7.4) and in the second and third degree relatives (SIR 1.5). There were significant excesses of CNS tumours diagnosed under the population median age (SIR 2.8 95% CI 1.1-5.8) in all relatives. Excess CNS tumours were also seen among relatives of children below the median age at diagnosis (SIR 3.2 95% CI 1.1-7.6). In conclusion, genetic susceptibility in some families of children with lymphoma might be operating, but aetiologies in HL and NHL appear to be different. Possible interpretations of our findings, in the context of putative genetic and infectious aetiologies, are discussed.

Further clues concerning the aetiology of childhood central nervous system tumours.

Previously, we reported space-time clustering and seasonal variation in childhood central nervous system (CNS) tumours for the period 1954-1998. These previous studies provided evidence that infections may be involved in aetiology. To determine whether there were also localised spatial factors involved in aetiology we analysed the geographical distribution of CNS tumours in children aged 0-14 years using Manchester Children's Tumour Registry (MCTR) data for the period 1976-2000. Specifically, the Potthoff-Whittinghill test for spatial clustering was applied and Poisson regression was used to analyse the relationship between incidence rates and small-area population density, ethnic composition and deprivation index. No relationships were seen for all CNS tumours together and only a few for the subgroups. The previous findings of space-time clustering and seasonal variation, involving astrocytoma and ependymoma, together with the lack of spatial clustering and ecological relationships for these tumours provide evidence that astrocytoma and ependymoma may be associated with a highly mobile transient aetiological agent. An example of such an agent is an infection that occurs in mini-epidemics.

Geographical and ecological analyses of childhood acute leukaemias and lymphomas in north-west England.

Childhood leukaemias and lymphomas have been associated with exposure to environmental factors, including infections, which show geographical variation. This study examined the geographical distribution of the incidence of acute leukaemia and lymphoma using Manchester Children's Tumour Registry (MCTR) data 1976-2000. A total of 910 children were included, all of whom had histologically and/or cytologically verified leukaemia or lymphoma. At the time of their diagnoses, all the children were aged 0-14 years and were resident in the counties of Greater Manchester or Lancashire. Standardized morbidity ratios were calculated. Poisson regression was used to examine the relationship between incidence rates and small-area (census ward) population density, ethnic composition and deprivation index. There was a monotonic relationship between acute lymphoblastic leukaemia (ALL) incidence and population density (P = 0.05). Higher rates were seen in more densely populated areas. There was evidence for a monotonic relationship between the incidence of the mixed cellularity subtype of Hodgkin's disease (HD) and the Townsend deprivation score (P = 0.001). Markedly higher incidence was associated with greater levels of unemployment and household overcrowding. The results for ALL and mixed cellularity HD support the involvement of environmental factors, such as infections, in disease aetiology.

Geographical and ecological analyses of childhood Wilms' tumours and soft-tissue sarcomas in North West England.

The aim of this paper was to study the geographical distribution of Wilms' tumours (WT) and soft-tissue sarcomas (STS) for 0-14 year olds included in a population-based registry from North West England during 1976-2000. Standardised morbidity ratios (SMRs) were calculated. Relationships between incidence rates and small area (ward) population density, ethnic composition, deprivation index and urban-rural status were examined using Poisson regression. There was a non-linear relationship between WT incidence and population density (P=0.008), with a higher incidence associated with wards with low deprivation scores (P=0.02); and which included a greater proportion of whites (P=0.01). For STS, a higher incidence was associated with wards with low deprivation scores (P=0.04); and which were 'more rural/less urban' (P=0.03). These results are consistent with a role for localised environmental exposures, in combination with lifestyle factors, in the aetiology of WT. For STS, there is some evidence for the involvement of environmental and/or lifestyle factors.