Is the risk of cancer increased in Asians living in the UK?

A Comparison of Late Mortality Among Survivors of Childhood Cancer in the United States and United Kingdom

BACKGROUND

It is unclear whether late-effect risks among childhood cancer survivors vary internationally. We compared late mortality in the North American Childhood Cancer Survivor Study (CCSS) and British Childhood Cancer Survivor Study (BCCSS).

METHODS

Late mortality was assessed among 49 822 5-year survivors of childhood cancer diagnosed before 15 years of age from 1970 to 1999 (CCSS, n = 31 596; BCCSS, n = 18 226) using cumulative mortality probabilities (CM%) and adjusted ratios of the standardized mortality ratio.

RESULTS

The all-cause CM% at 10 years from diagnosis was statistically significantly lower in the CCSS (4.7%, 95% confidence interval [CI] = 4.5% to 5.0%) compared with the BCCSS (6.9%, 95% CI = 6.5% to 7.2%), attributable to a lower probability of death from recurrence or progression of the primary cancer, with statistically significant differences observed in survivors of leukemia, lymphoma, central nervous system tumors, and sarcoma. However, at 40 years from diagnosis, the CCSS had a greater CM% (22.3% vs 19.3%), attributable to a twofold higher risk of mortality from subsequent malignant neoplasms, cardiac and respiratory diseases, and other health-related causes. Differences increased when assessed by follow-up interval, with the CCSS faring worse as time-since-diagnosis increased. Finally, the gap in all-cause mortality widened more recently, with CCSS survivors diagnosed in 1990-1999 experiencing one-half the excess deaths observed in the BCCSS (ratios of the standardized mortality ratio = 0.5, 95% CI = 0.5 to 0.6).

CONCLUSIONS

Our findings suggest that US survivors may have received more intensive regimens to achieve sustainable remission and cure, but the cost of this approach was a higher risk of death from late effects. Although the clinical impact of these differences is unclear, our results provide important evidence to aid the discussion of late effects management.

Comparison of ethnic group classification using naming analysis and routinely collected data: application to cancer incidence trends in children and young people

OBJECTIVE

Inpatient Hospital Episode Statistics (HES) ethnicity data are available but not always collected and data quality can be unreliable. This may have implications when assessing outcomes by ethnicity. An alternative method for assigning ethnicity is using naming algorithms. We investigate if the association between ethnicity and cancer incidence varied dependent on how ethnic group was assigned.

DESIGN

Population-based cancer registry cohort study.

SETTING

Yorkshire, UK.

PARTICIPANTS

Cancer registrations from 1998 to 2009 in children and young people (0-29 years) from a specialist cancer register in Yorkshire, UK (n=3998) were linked to inpatient HES data to obtain recorded ethnicity. Patients' names, recorded in the cancer register, were matched to an ethnic group using the naming algorithm software Onomap. Each source of ethnicity was categorised as white, South Asian (SA) or Other, and a further two indicators were defined based on the combined ethnicities of HES and Onomap, one prioritising HES results, the other prioritising Onomap.

OUTCOMES

Incidence rate ratios (IRR) between ethnic groups were compared using Poisson regression for all cancers combined, leukaemia, lymphoma and central nervous system (CNS) tumours.

RESULTS

Depending on the indicator used, 7.1%-8.6% of the study population were classified as SA. For all cancers combined there were no statistically significant differences between white and SA groups using any indicator; however, for lymphomas significant differences were only evident using one of the 'Combined' indicators (IRR=1.36 (95% CI 1.08 to 1.71)), and for CNS tumours incidence was lower using three of the four indicators. For the other ethnic group the IRR for all cancers combined ranged from 0.78 (0.65 to 0.94) to 1.41 (1.23 to 1.62).

CONCLUSIONS

Using different methods of assigning ethnicity can result in different estimates of ethnic variation in cancer incidence. Combining ethnicity from multiple sources results in a more complete estimate of ethnicity than the use of one single source.

Childhood cancer incidence by ethnic group in England, 2001-2007: a descriptive epidemiological study

BACKGROUND

After the first year of life, cancers are the commonest cause of death in children. Incidence rates vary between ethnic groups, and recent advances in data linkage allow for a more accurate estimation of these variations. Identifying such differences may help identify potential risk or protective factors for certain childhood cancers. This study thus aims to ascertain whether such differences do indeed exist using nationwide data across seven years, as have previously been described in adult cancers.

METHODS

We obtained data for all cancer registrations for children (aged 0-14) in England from January 2001 to December 2007. Ethnicity (self-assigned) was established through record linkage to the Hospital Episodes Statistics database or cancer registry data. Cancers were classified morphologically according to the International Classification of Childhood Cancer into four groups - leukaemias; lymphomas; central nervous system; and other solid tumours. Age standardised incidence rates were estimated for each ethnic group, as well as incidence rate ratios comparing each individual ethnic group (Indian, Pakistani, Bangladeshi, Black African, Black Carribean, Chinese) to Whites, adjusting for sex, age and deprivation.

RESULTS

The majority of children in the study are UK born. Black children (RR = 1.18, 99% CI: 1.01-1.39), and amongst South Asians, Pakistani children (RR = 1.19, 99% CI: 1.02-1.39) appear to have an increased risk of all cancers. There is an increased risk of leukaemia in South Asians (RR = 1.31, 99% CI: 1.08-1.58), and of lymphoma in Black (RR = 1.72, 99% CI: 1.13-2.63) and South Asian children (RR = 1.51, 99% CI: 1.10-2.06). South Asians appear to have a decreased risk of CNS cancers (RR = 0.71, 99% CI: 0.54-0.95).

CONCLUSIONS

In the tradition of past migrant studies, such descriptive studies within ethnic minority groups permit a better understanding of disease incidence within the population, but also allow for the generation of hypotheses to begin to understand why such differences might exist. Though a major cause of mortality in this age group, childhood cancer remains a relatively rare disease; however, the methods used here have permitted the first nationwide estimation of childhood cancer by individual ethnic group.

Gastric teratoma: A series of 7 cases

BACKGROUND

Gastric teratoma is a rare entity comprising less than 1% of germ cell tumors of childhood. We present a series of seven gastric teratomas with a review of literature.

OBJECTIVE

To study the demographic profile, clinicopathological features and follow-up data of gastric teratomas.

METHODS

We did a retrospective analysis of 7 cases of gastric teratomas more than 15years and studied their demographic profiles, clinicopathological features and follow-up data.

RESULTS

We came across 7 cases of gastric teratomas out of which 5 were mature and 2 were immature. One case of immature teratoma came back with recurrence and another one had an unusual finding of presence of renal and pulmonary tissues, which has not been reported earlier.

CONCLUSION

Ours is the second largest case series of gastric teratomas in the pediatric age group and 2 out of 7 of our cases had immature elements. We also take this opportunity to report a case of gastric teratoma with the unusual histological finding of immature renal and pulmonary tissues, which has not been described previously.

Childhood cancer incidence in British Indians & Whites in Leicester, 1996-2008

BACKGROUND

South Asians in England have an increased risk of childhood cancer but incidence by their individual ethnicities using self-assigned ethnicity is unknown. Our objective was to compare the incidence of childhood cancer in British Indians and Whites in Leicester, which has virtually complete, self-assigned, ethnicity data and the largest population of Indians in England.

METHODS

We obtained data on all cancer registrations from 1996 to 2008 for Leicester with ethnicity obtained by linkage to the Hospital Episodes Statistics database. Age-standardised incidence rates were calculated for childhood cancers in Indians and Whites as well as rate ratios, adjusted for age.

RESULTS

There were 33 cancers registered among Indian children and 39 among White children. The incidence rate for Indians was greater compared to Whites for all cancers combined (RR 1.82 (95% CI 1.14 to 2.89); p = 0.01), with some evidence of increased risk of leukaemia (RR 2.20 (0.95 to 5.07); p = 0.07), lymphoma (RR 3.96 (0.99 to 15.84); p = 0.04) and central nervous system tumours (RR 2.70 (1.00 to 7.26); p = 0.05). Rates were also higher in British Indian children compared to children in India.

CONCLUSIONS

British Indian children in Leicester had an increased risk of developing cancer compared to White children, largely due to a higher incidence of central nervous system and haematological malignancies.

Cultural Beliefs and Coping Strategies Related to Childhood Cancer

The purpose of this study is to describe cultural beliefs and coping strategies related to dealing with childhood cancer identified through a qualitative study of the caregiving experiences of first-generation South Asian immigrant parents of children with cancer. A constructivist grounded theory approach was employed. Families with a child at least 6 months postdiagnosis were recruited from 5 Canadian pediatric oncology centers. In-depth semistructured interviews were conducted in English, Hindi, Punjabi, or Urdu with a sample of 25 South Asian parents. Analysis of interviews involved line-by-line coding and using the constant comparison method. The following 2 central themes related to culture and coping emerged: (a) cultural beliefs about childhood cancer being incurable, rare, unspeakable, and understood through religion and (b) parental coping strategies included gaining information about the child’s cancer, practicing religious rituals and prayers, trusting the health care professionals, and obtaining mutual support from other South Asian parents. These cultural beliefs and coping strategies have important implications for health care providers to understand the variations in the perceptions of childhood cancer and coping in order to implement culturally sensitive health care services.

Cancer incidence among the south Asian and non-south Asian population under 30 years of age in Yorkshire, UK

Background:

Few studies have examined epidemiological differences between ethnic groups for children and young adults with cancer.

Methods:

Subjects aged 0–29 years, diagnosed between 1990 and 2005 in the former Yorkshire Regional Health Authority, were included in the analysis. Ethnicity (south Asian or not) was assigned using name analysis program and Hospital Episode Statistics data. Differences in incidence (per 1 000 000 person-years) rates and trends were analysed using joinpoint and Poisson regression analysis.

Results:

Overall cancer incidence was similar for south Asians (12.1, 95% CI: 10.7–13.5; n=275) and non-south Asians (12.6, 95% CI: 12.2–13.1; n=3259). Annual incidence rates increased significantly by 1.9% per year on average (95% CI: 1.2–2.6%), especially for south Asians (7.0% 95% CI: 4.2–9.9%).

Conclusion:

If present trends continue, the higher rate of increase seen among south Asians aged 0–29 years in Yorkshire will result in three times higher cancer incidence than non-south Asians by 2020.

Fifty years of paediatric malignant bone tumours in the West Midlands, UK, 1957-2006: incidence, treatment and outcome

Malignant bone tumours in the paediatric age group (0-14 years) are uncommon; various aetiological theories exist and few reports of incidence, age and sex distributions have been published. We examined the incidence of childhood malignant bone tumours in one large single region of the UK over an extended period of 50 years. The West Midlands specialist regional children's tumour registry holds data on all malignancies and benign brain tumours in children under 15 years in the West Midlands region, which has a population of around 1 million children. Demographic and clinical data have been abstracted and diagnoses reviewed by a panel of expert pathologists. During the period 1957-2006, 259 cases of malignant paediatric bone tumours were diagnosed. There were 153 osteosarcomas, 78 Ewing sarcomas and 28 other primary bone tumours. The overall age standardised rate was 4.66, with no increase over time, although there was a significant increase in the incidence of Ewing sarcomas in the period 1965-92. Sixty-eight per cent of tumours were in patients over 10 years, whereas the incidence in patients under 10 years showed a non-significant increase. Survival rates increased dramatically post-chemotherapy introduction, with Ewing sarcoma demonstrating better survival overall. This is a large study giving an overview of malignant bone tumours in the childhood population of a single region over an extended period, showing results consistent with national reports. It also examines late effects, which were mostly mobility/orthopaedic, although almost one-fifth of patients had cardiac problems and five went on to develop second malignancies.

Childhood cancer in relation to parental race and ethnicity: a 5-state pooled analysis

BACKGROUND

Children of different racial/ethnic backgrounds have varying risks of cancer. However, to the authors' knowledge, few studies to date have examined cancer occurrence in children of mixed ancestry.

METHODS

This population-based case-control study examined cancer among children aged <15 years using linked cancer and birth registry data from 5 US states from 1978 through 2004. Data were available for 13,249 cancer cases and 36,996 controls selected from birth records. Parental race/ethnicity was determined from birth records. Logistic regression analysis was used to examine the association of cancer with different racial/ethnic groups.

RESULTS

Compared with whites, blacks had a 28% decreased risk of cancer (odds ratio [OR], 0.72; 95% confidence interval [95% CI], 0.65-0.80), whereas both Asians and Hispanics had an approximate 15% decrease. Children of mixed white/black ancestry also were found to be at decreased risk (OR, 0.71; 95% CI, 0.56-0.90), but estimates for mixed white/Asian and white/Hispanic children did not differ from those of whites. Compared with whites: 1) black and mixed white/black children had decreased ORs for acute lymphoblastic leukemia (OR, 0.39 [95% CI, 0.31-0.49] and OR, 0.58 [95% CI, 0.37-0.91], respectively); 2) Asian and mixed white/Asian children had decreased ORs for brain tumors (OR, 0.51 [95% CI, 0.39-0.68] and OR, 0.79 [95% CI, 0.54-1.16], respectively); and 3) Hispanic and mixed white/Hispanic children had decreased ORs for neuroblastoma (OR, 0.51 [95% CI, 0.42-0.61] and OR, 0.67 [95% CI, 0.50-0.90], respectively).

CONCLUSIONS

Children of mixed ancestry tend to have disease risks that are more similar to those of racial/ethnic minority children than the white majority group. This tendency may help formulate etiologic studies designed to study possible genetic and environmental differences more directly.

The epidemiology of neuroblastoma: a review

Neuroblastoma is the most common tumour in children less than 1 year of age. The goal of this review was to summarise the existing epidemiological research on risk factors for neuroblastoma. A comprehensive search of the literature was undertaken using PubMed for epidemiological studies on neuroblastoma risk factors. We ascertained 47 articles which examined the risk factors. Ten studies employed population-based case-control designs; six were hospital-based case-control studies; two were cohort studies; and five employed ecological designs. Studies ranged in size from 42 to 538 cases. Three studies showed evidence of an increased risk of disease with use of alcohol during pregnancy (OR range 1.1, 12.0). Protective effects were seen with maternal vitamin intake during pregnancy (OR range 0.5, 0.7) in two studies, while risk of disease increased with maternal intake of diuretics (OR range 1.2, 5.8) in three studies. Three studies reported a decrease in risk for children with a history of allergic disease prior to neuroblastoma diagnosis (OR range 0.2, 0.4). The rarity of neuroblastoma makes this disease particularly challenging to study epidemiologically. We review the methodological limitations of prior research and make suggestions for further areas of study.

Phase I and Phase II Enzyme Polymorphisms and Childhood Cancer

Childhood cancers continue to be challenging clinical entities whose etiology, demographic characteristics, clinical progression, treatment efficacy, and outcomes remain incompletely understood. Research suggests that multiple environmental and genetic factors may play crucial roles in the pathophysiology of many of these malignancies. Recent attention has been directed to the role of carcinogen metabolizing enzymes in the etiology and progression of cancer in both adults and children due to their multitude of polymorphic variants and their intimate interaction with environmental factors. In particular, xenobiotic metabolizing enzymes (XME), which are intimately involved in the activation and deactivation of many environmental carcinogens, have become an area of significant interest. Traditionally, these enzymes have been classified into either phase I or phase II enzymes depending on their substrates, activity, and occasionally based on their sequence in the metabolic pathways, and have been demonstrated to have numerous polymorphic variants. Phase I enzymes predominantly consist of cytochrome enzymes responsible for mixed function oxidase activity, whereas phase II enzymes are frequently conjugation reactions necessary for drug metabolism or the further metabolism of phase I enzyme products. Current research has discovered numerous interactions between polymorphisms in these enzymes and changes in cancer susceptibility, treatment efficacy, and clinical outcomes in childhood cancer. Furthermore, studies of polymorphisms in these enzymes have demonstrated to have synergistic/antagonistic interactions with other XME polymorphisms and demonstrate variable influences on disease pathophysiology depending on the patient's ethnic background and environmental milieu. Continuing research on the role of polymorphisms in phase I and phase II enzymes will likely further elucidate the intimate role of these polymorphisms with environmental factors in the etiology of childhood cancer.

Potential barriers to prevention of cancers and to early cancer detection among Irish people living in Britain: a qualitative study

OBJECTIVES

To identify and explore explanatory models of cancer among Irish and white British people living in Britain.

METHODS

Ethnographic in-depth interviews and focus groups were conducted in London, Manchester and Glasgow, with a total of 58 (n = 58) Irish and 57 (n = 57) white British participants. The study samples were broadly similar in socio-demographic characteristics.

RESULTS

We explored explanatory models (lay beliefs) used by the Irish and white British to understand their cancer-related beliefs and behaviours. Among both groups there was confusion about causation, poor knowledge of signs and symptoms, and a general pessimism about cancer prevention and treatments. The narratives of the Irish were, however, qualitatively different from those of the white British. Historical, cultural, social and economic circumstances, both in the UK and in the past in Ireland, appeared to influence views of cancer and health-seeking behaviours. Recollections of negative family experiences of cancers linked to 'stigma' and 'secrecy', poor outcomes and medical practices in rural Ireland, particularly among the older Irish, influenced Irish understanding of cancers and help-seeking behaviours. The second generation also appeared to retain some beliefs that were common amongst the first generation migrants. The context of migration was also felt by the Irish group to have exposed them to living and working environments that made them susceptible to cancers.

CONCLUSION

The Irish frame of reference was firmly embedded in a specific historical, social and economic context which may contribute to cultural constraints on discussions about cancers and to the lack of engagement with preventative behaviours and health care services.

Cancer incidence in the south Asian population of California, 1988-2000

BACKGROUND

Although South Asians (SA) form a large majority of the Asian population of U.S., very little is known about cancer in this immigrant population. SAs comprise people having origins mainly in India, Pakistan, Bangladesh and Sri Lanka. We calculated age-adjusted incidence and time trends of cancer in the SA population of California (state with the largest concentration of SAs) between 1988-2000 and compared these rates to rates in native Asian Indians as well as to those experienced by the Asian/Pacific Islander (API) and White, non-Hispanic population (NHW) population of California.

METHODS

Age adjusted incidence rates observed among the SA population of California during the time period 1988-2000 were calculated. To correctly identify the ethnicity of cancer cases, 'Nam Pehchan' (British developed software) was used to identify numerator cases of SA origin from the population-based cancer registry in California (CCR). Denominators were obtained from the U.S. Census Bureau. Incidence rates in SAs were calculated and a time trend analysis was also performed. Comparison data on the API and the NHW population of California were also obtained from CCR and rates from Globocan 2002 were used to determine rates in India.

RESULTS

Between 1988-2000, 5192 cancers were diagnosed in SAs of California. Compared to rates in native Asian Indians, rates of cancer in SAs in California were higher for all sites except oropharyngeal, oesophageal and cervical cancers. Compared to APIs of California, SA population experienced more cancers of oesophagus, gall bladder, prostate, breast, ovary and uterus, as well as lymphomas, leukemias and multiple myelomas. Compared to NHW population of California, SAs experienced more cancers of the stomach, liver and bile duct, gall bladder, cervix and multiple myelomas. Significantly increasing time trends were observed in colon and breast cancer incidence.

CONCLUSION

SA population of California experiences unique patterns of cancer incidence most likely associated with acculturation, screening and tobacco habits. There is need for early diagnosis of leading cancers in SA. If necessary steps are not taken to curb the growth of breast, colon and lung cancer, rates in SA will soon approximate those of the NHW population of California.

Patterns of childhood cancer by ethnic group in Bradford, UK 1974-1997

The highly urbanised northern English city of Bradford contains a diverse population from different ethnic backgrounds, including a high proportion of south Asians. We aimed to identify the effect of ethnic group on the incidence and temporal trends of childhood cancer in Bradford. Children (0-14 years) from the district of Bradford, who were diagnosed with a malignancy between 1974 and 1997, were selected from a population-based register. Each child was classified as south Asian (Indian, Pakistani and Bangladeshi), or not, based on their full name using 2 computer algorithms and individual inspection. Mid-year population estimates were used to calculate incidence rates and differences were assessed using Poisson regression. The study included 318 children, of whom 81 (25%) were south Asian. The incidence of all cancers in south Asian children (14.9 per 100,000 person years, 95% CI 11.6-18.2) was higher than non-south Asian children (12.0, 10.5-13.5) although not significantly so (P=0.14). Comparisons by diagnostic subgroup showed no major differences apart from significantly higher rates of acute myeloid leukaemia (AML) in south Asian children (1.9 versus 0.7, P=0.02). The age-specific incidence peaks of all childhood cancers and leukaemias were present in south Asian children aged 5-9 years compared with 0-4 years olds in the non-south Asian population. Non-significant increases of 1.4 and 1.5% in the average annual incidence of all cancers were seen for south Asians and non-south Asians respectively, with a significant rise for non-south Asians with leukaemia of 3.0% (P=0.04). Our timely study shows patterns of occurrence of childhood cancer that differ with respect to ethnic group. Differences are particularly apparent in the excess of AML and incidence peak in 5-9 year olds in south Asian children.

Ethnicity in pressure ulcer risk assessment, with specific relation to the Pakistani ethnic minority in Burton, England

BACKGROUND

There has been little work on ethnicity related to pressure ulcers in general and little or nothing specific to South Asians, and the Pakistani ethnic group in particular.

AIM

To explore the relevance of ethnicity in pressure ulcers.

METHODS

All admissions over a 5-year period to a District General Hospital in Burton, United Kingdom (UK) were considered where data were present on Waterlow Score, ethnicity and pressure sore status. Logistic regression analysis was conducted using ethnicity and other variables to predict ulcer formation. RESULTS; Age is predictive, but ethnicity was not found to be a significant predictor.

CONCLUSION

There is no evidence that members of the Pakistani ethnic minority are at higher risk than the majority White population in Burton, with respect to pressure ulcers.

Hodgkin's disease in Asians: incidence patterns and risk factors in population-based data

Hodgkin's disease (HD) has been reported to be rare in Asians. Data sparseness has hindered studies exploring the relative contributions of environment and heredity to HD etiology, and individual risk factors have never been studied in an Asian population. With the most recent, uniformly collected population-based data from the US and Asia, we compared HD incidence rates in Chinese, Japanese, Filipinos, and Asian Indians in the US and in Asia. HD incidence rates were quite low in all Asian subgroups, but approximately double in US Asians as in native Asians. In both, rates were lower for Japanese and Chinese than for Filipinos and Asian Indians. A modest young-adult rate peak occurred for most US Asian groups, but not for any population in Asia. In data from a population-based case-control study of HD in San Francisco area women, young-adult Asian cases, like young-adult cases of other racial/ethnic groups, had childhood social environments indicative of less early contact with children. Given environmental and lifestyle differences between the US and Asia, the consistently low rates of HD in Asians suggest genetic resistance to disease development, possibly associated with HLA type. International and inter-ethnic differences, and risk factor patterns in case-control data, implicate environmental influences in the etiology of HD.

South Asian ethnicity and material deprivation increase the risk of Epstein-Barr virus infection in childhood Hodgkin's disease

In order to further define the factors associated with the observed variations in the Epstein-Barr virus-positive rate in childhood Hodgkin's disease, we have studied the effect of material deprivation (measured by the Townsend score) and ethnic origin on the frequency of Epstein-Barr virus-positivity in 55 cases of childhood Hodgkin's disease, diagnosed between 1981 and 1999, from a multi-ethnic region of the United Kingdom. Epstein-Barr virus status was determined by immunohistochemistry for the Epstein-Barr virus-encoded latent membrane protein-1. 62% of cases were Epstein-Barr virus-positive. Ethnic group was the strongest predictor of Epstein-Barr virus-positivity, with South Asians having a more than 20-fold risk of being Epstein-Barr virus-positive compared with non-South Asians. An increased risk was still present after adjusting for deprivation. Townsend scores were significantly higher (indicating more deprivation) in the Epstein-Barr virus-positive group, particularly in males. The relative risk of Epstein-Barr virus-positivity showed a gradient with increasing Townsend score; the risk being 7-times higher in the most deprived quartile compared with the least deprived group. Although the association between Townsend score and Epstein-Barr virus-positivity was reduced after adjusting for ethnic group, the risk of Epstein-Barr virus-positivity was still 3-times higher in the most deprived compared with the least deprived quartile. In addition, cases having 2 or more siblings were 5-times as likely to be Epstein-Barr virus-positive as those from smaller families. These results provide the first evidence of a strong association between Epstein-Barr virus-positive Hodgkin's disease and South Asian children from the United Kingdom. In addition, deprivation may increase the likelihood of Epstein-Barr virus-positive disease independently of ethnicity.

Cancer and men from minority ethnic groups: an exploration of the literature

The authors reviewed literature which has been published in the last 20 years. Cancer is the second leading cause of death in developed countries and is expected to become a significant cause of death in developing countries. Whilst there are a large number of studies on cancer and men, there is a paucity of data on men from minority ethnic groups. In the USA, African Americans are more likely to develop cancer than any other ethnic group. Although cancer rates amongst minority ethnic groups in the UK are thought to be low, 11% of Indian and African men and 19% of Caribbean men died from cancer during 1979-1983. There is also further evidence in the USA that African American, Filipinos and Native Americans have the lowest cancer survival rates. Service utilization, especially tertiary care, is also thought to be low amongst minority ethnic groups from the USA and the UK. Reasons for these variations include artefactual, cultural, materialist and social selectivist explanations as well as the effects of migration, racism and genetic disposition. This area is under-researched, in particular cultural beliefs about cancer. Further research into this area should apply culturally competent methods to ensure valid data to inform cancer policy, education and practice.

Ethnic group and survival from childhood cancer: report from the UK Children's Cancer Study Group

Survival following cancer was analysed in relation to ethnic group among children diagnosed in Britain during 1981-1996 and treated at paediatric oncology centres by members of the UK Children's Cancer Study Group. Survival was analysed for 11 diagnostic groups: acute lymphoblastic leukaemia (ALL), acute non-lymphocytic leukaemia, Hodgkin's disease, non-Hodgkin's lymphoma, astrocytoma, primitive neuroectodermal tumour, neuroblastoma, Wilms' tumour, osteosarcoma, Ewing's sarcoma and rhabdomyosarcoma. There were no significant differences in survival between White and non-White children over the study period as a whole. Among children with ALL, however, the relative risk of death allowing for period of diagnosis, age and white blood count was 1.25 for those of South Asian ethnic origin compared with Whites (P = 0.057).

Survival from childhood cancer in Yorkshire, U.K.: effect of ethnicity and socio-economic status

The effect of ethnicity and socio-economic status on the survival of a population-based cohort of 1979 children diagnosed with cancer between 1974 and 1995 was investigated. Ethnicity was assigned by computer algorithms and visual inspection as south Asian (or not) for each child, based on their full name. Socio-economic status was measured using the Carstairs index, based on census areas of case residence at diagnosis. 15 children (0.8%) were lost to follow-up. Log-rank tests showed survival from all cancers did not differ between south Asians and other children and no increased risk was observed for south Asians in any diagnostic category, although numbers were small. Increasing levels of deprivation were associated with significant trends of poorer survival from all cancers, leukaemias and brain tumours. Risk of death was typically higher for children from the most deprived areas although differences were not statistically significant after accounting for other factors including ethnicity. Taking all children with malignant disease together, neither ethnicity nor socio-economic status appear to influence survival after taking other factors into consideration.

Cancer incidence in the south Asian population of England (1990-92)

Cancer incidence among English south Asians (residents in England with ethnic origins in India, Pakistan or Bangladesh) is described and compared with non-south Asian and Indian subcontinent rates. The setting for the study was areas covered by Thames, Trent, West Midlands and Yorkshire cancer registries. The study identified 356 555 cases of incident cancer (ICD9:140-208) registered between 1990 and 1992, including 3845 classified as English south Asian. The main outcome measures were age specific and directly standardized incidence rates for all cancer sites (ICD9:140-208). English south Asian incidence rates for all sites combined were significantly lower than non-south Asian rates but higher than Indian subcontinent rates. English south Asian rates were substantially higher than Indian subcontinent rates for a number of common sites including lung cancer in males, breast cancer in females and lymphoma in both sexes. English south Asian rates for childhood and early adult cancer (0-29 years) were similar or higher than non-south Asian rates. English south Asian rates were significantly higher than non-south Asian rates for Hodgkin's disease in males, cancer of the tongue, mouth, oesophagus, thyroid gland and myeloid leukaemia in females, and cancer of the hypopharynx, liver and gall bladder in both sexes. The results are consistent with a transition from the lower cancer risk of the country of ethnic origin to that of the country of residence. They suggest that detrimental changes in lifestyle and other exposures have occurred in the migrant south Asian population.

What causes Hodgkin's disease in children?

Hodgkin's disease is one of the commonest cancers of older children and adolescents, but little is known about its aetiology. Recent data, particularly in descriptive epidemiology and virology, tend to confirm the 'two-disease' hypothesis. Mixed cellularity Hodgkin's disease is more common, especially at younger ages, in poorer socioeconomic environments, whereas nodular sclerosing Hodgkin's disease has a higher incidence in more affluent societies. Approximately three-quarters of childhood Hodgkin's disease, and a higher proportion of the mixed cellularity subtype, may be a rare response to Epstein-Barr virus infection, together with an unidentified cofactor related to the degree of affluence of the population. Other infectious agents may be implicated in some cases. The already low incidence, especially of nodular sclerosis, among populations of East Asian ethnic origin and the high incidence, especially of mixed cellularity, among some populations of South Asian origin are apparently independent of socioeconomic status. This ethnic variation in risk suggests that genetic predisposition also plays a role. Detailed HLA studies may help to elucidate the complex variations between populations in the risk of Hodgkin's disease and its principal subtypes.

High risk of lymphomas in children of Asian origin: ethnicity or confounding by socioeconomic status?

To examine the role of ethnic origin as a risk factor for paediatric lymphoma, a cancer registry-based analysis was undertaken in Yorkshire, UK. Children of Asian ethnic origin were found to have an odds ratio for lymphomas of 1.60 (CI 0.98-2.62), after adjusting for age and sex. After adjusting also for 'super profile group' as an indicator of socioeconomic status, the estimate became 1.99 (CI 1.08-3.68). Hodgkin's disease and non-Hodgkin's lymphomas were analysed separately with similar results. Super profile group is an area-based measure and may not reflect the individual variation in living standards, especially among the Asian immigrants. Our results indicate that socioeconomic status does not confound the relationship between lymphomas and ethnic origin. However, there is a need for studies of ethnicity that include indicators of individual living standards or socioeconomic status.

Cancer in minority ethnic populations: priorities from epidemiological data

The aim of this paper is to review the literature on the frequency of cancers to develop priorities for cancer policy, prevention, services and research for black and minority ethnic populations in Britain. Data on populations originating in the Indian sub-continent, and Caribbean and African Commonwealth were extracted from published works. Cancers were ranked (top seven) on the basis of the number of cases, actual frequency, and also on relative frequency (SMR, SRR, PMR). Cancer was found to be a common cause of death. For example, during 1979-83 the proportion of deaths resulting from neoplasms in immigrants living in England and Wales was 11% for Indian and African men aged 20-49, and 19% for Caribbeans. The corresponding proportions were higher among women. The pattern of cancer depended on the method used to assess rankings. On the basis of the number of cases the top 3 ranking cancers for adults were breast, long and neoplasms of the lymphatic system. Based on SMR's cancer of the gallbladder, liver and oral cavity ranked amongst the top 3 for adults. For children the top ranking cancers were acute lymphoblastic leukaemia, central nervous system tumours and neuroblastoma. Variations by ethnic group were more evident in the rankings of relative frequency than in rankings based on numbers of cases. In conclusion, the most common and preventable cancers among minority ethnic populations were the same as those for the general population. The different cancer pattern based on SMRs highlight additional needs and provide potential models for research into understanding the causes of these cancers. Health services policy and practice should ensure that the common and preventable cancers take priority over rare cancers and those for which there is no effective treatment or prevention. Priorities for policy, prevention, clinical care and research should be set separately, for they differ.

Cancer and congenital abnormalities in Asian children: a population-based study from the West Midlands

Cancer and associated congenital abnormalities were investigated in Muslim and non-Muslim Asian children from the West Midlands. Cancer incidence rates were calculated for Indian (non-Muslim), Pakistani/Bangladeshi (Muslim) and white children diagnosed from 1978 to 1992. Incidence was significantly higher in the Pakistanis, with an age-standardised rate (ASR) of 163 cases per million per year, compared with 115 for Indian and 125 for white children. Among Asian cancer patients, congenital malformations were significantly more common in Muslim (21%) compared with non-Muslim (7%). In Muslims the malformation excess was caused by autosomal recessive and dominant disorders (in 8% and 5% of cases respectively). Cancer malformation/predisposition syndromes were found in 10% of Muslims, compared with 2% of non-Muslims. In 33% of the Muslims with malformations, childhood cancer and a malformation were also present in a close relative. None of the non-Muslims with malformations had a relative with childhood cancer. The cancer excess in Muslims may be partly related to inherited genes causing both malformations and cancer. The prevalence of autosomal recessive disorders may be related to consanguinity, which is common in the Pakistani Muslim population. The high incidence of autosomal dominant disorders may be related to older paternal age at conception, giving rise to spontaneous mutations.