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.

Nervous System and Intracranial Tumour Incidence by Ethnicity in England, 2001-2007: A Descriptive Epidemiological Study.

BACKGROUND: There is substantial variation in nervous system and intracranial tumour incidence worldwide. UK incidence data have limited utility because they group these diverse tumours together and do not provide data for individual ethnic groups within Blacks and South Asians. Our objective was to determine the incidence of individual tumour types for seven individual ethnic groups. METHODS: We used data from the National Cancer Intelligence Network on tumour site, age, sex and deprivation to identify 42,207 tumour cases. Self-reported ethnicity was obtained from the Hospital Episode Statistics database. We used mid-year population estimates from the Office for National Statistics. We analysed tumours by site using Poisson regression to estimate incidence rate ratios comparing non-White ethnicities to Whites after adjustment for sex, age and deprivation. RESULTS: Our study showed differences in tumour incidence by ethnicity for gliomas, meningiomas, pituitary tumours and cranial and paraspinal nerve tumours. Relative to Whites; South Asians, Blacks and Chinese have a lower incidence of gliomas (p<0.01), with respective incidence rate ratios of 0.68 (confidence interval: 0.60-0.77), 0.62 (0.52-0.73) and 0.58 (0.41-0.83). Blacks have a higher incidence of meningioma (p<0.01) with an incidence rate ratio of 1.29 (1.05-1.59) and there is heterogeneity in meningioma incidence between individual South Asian ethnicities. Blacks have a higher incidence of pituitary tumours relative to Whites (p<0.01) with an incidence rate ratio of 2.95 (2.37-3.67). There is heterogeneity in pituitary tumour incidence between individual South Asian ethnicities. CONCLUSIONS: We present incidence data of individual tumour types for seven ethnic groups. Current understanding of the aetiology of these tumours cannot explain our results. These findings suggest avenues for further work.

Incidence of prostate and urological cancers in England by ethnic group, 2001-2007: a descriptive study.

BACKGROUND: The aetiology of urological cancers is poorly understood and variations in incidence by ethnic group may provide insights into the relative importance of genetic and environmental risk factors. Our objective was to compare the incidence of four urological cancers (kidney, bladder, prostate and testicular) among six 'non-White' ethnic groups in England (Indian, Pakistani, Bangladeshi, Black African, Black Caribbean and Chinese) to each other and to Whites. METHODS: We obtained Information on ethnicity for all urological cancer registrations from 2001 to 2007 (n = 329,524) by linkage to the Hospital Episodes Statistics database. We calculated incidence rate ratios adjusted for age, sex and income, comparing the six ethnic groups (and combined 'South Asian' and 'Black' groups) to Whites and to each other. RESULTS: There were significant differences in the incidence of all four cancers between the ethnic groups (all p < 0.001). In general, 'non-White' groups had a lower incidence of urological cancers compared to Whites, except prostate cancer, which displayed a higher incidence in Blacks. (IRR 2.55) There was strong evidence of differences in risk between Indians, Pakistanis and Bangladeshis for kidney, bladder and prostate cancer (p < 0.001), and between Black Africans and Black Caribbeans for all four cancers (p < 0.001). CONCLUSIONS: The risk of urological cancers in England varies greatly by ethnicity, including within groups that have traditionally been analysed together (South Asians and Blacks). In general, these differences are not readily explained by known risk factors, although the very high incidence of prostate cancer in both black Africans and Caribbeans suggests increased genetic susceptibility. g.

Incidence of breast and gynaecological cancers by ethnic group in England, 2001-2007: a descriptive study.

BACKGROUND: Although international comparisons reveal large geographical differences in the incidence of breast and gynaecological cancers, incidence data for ethnic groups in England remains scarce. METHODS: We compared the incidence of breast, ovarian, cervical and endometrial cancer in British Indians, Pakistanis, Bangladeshis, Black Africans, Black Caribbeans, Chinese and Whites between 2001 and 2007. We identified 357,476 cancer registrations from which incidence rates were calculated using mid-year population estimates from 2001 to 2007. Ethnicity was obtained through linkage to the Hospital Episodes Statistics database. Incidence rate ratios were calculated, comparing the 6 non-White ethnic groups to Whites, and were adjusted for age and income. RESULTS: We found evidence of differences in the incidence of all 4 cancers by ethnic group (p<0.001). Relative to Whites, South Asians had much lower rates of breast, ovarian and cervical cancer (IRRs of 0.68, 0.66 and 0.33 respectively), Blacks had lower rates of breast, ovarian and cervical cancer but higher rates of endometrial cancer (IRRs of 0.85, 0.62, 0.72 and 1.16 respectively), and Chinese had lower rates of breast and cervical cancer (IRRs of 0.72 and 0.68 respectively). There were also substantial intra-ethnic differences, particularly among South Asians, with Bangladeshis experiencing the lowest rates of all 4 cancers. CONCLUSIONS: Our study provides evidence that the risk of breast and gynaecological cancers varies by ethnic group and that those groups typically grouped together are not homogenous with regards to their cancer risk. Furthermore, several of our findings cannot be readily explained by known risk factors and therefore warrant further investigation.

Incidence of haematological malignancies by ethnic group in England, 2001-7.

The aetiology of most haematological malignancies is largely unknown. Studies of migrant populations can provide insights into the relative importance of genetic and environmental risk factors for these diseases. This study compares incidence rates in British Indians, Pakistanis, Bangladeshis, Black Africans, Black Caribbeans, Chinese and Whites in England from 2001 to 2007. We analysed 134,302 haematological cancer registrations with ethnicity obtained by linkage to the Hospital Episodes Statistics database. Mid-year population estimates from 2001 to 2007 were used. Incidence rate ratios adjusted for age, sex and income were calculated, comparing the six ethnic groups to Whites and to each other. Whites had the highest rates for most subtypes. However, Blacks experienced more than double the incidence of plasma cell and mature T-cell neoplasms compared to other ethnic groups. There were also significant differences in incidence between Indians, Pakistanis and Bangladeshis for Hodgkin lymphoma and mature B-cell neoplasms and between Black African and Black Caribbeans for mature B-cell and other lymphoid neoplasms (all P < 0.001). Our results show that the risk of haematological cancers varies greatly by ethnic group, including within those groups that have traditionally been grouped together (South Asians and Blacks) with many of these differences not explicable by known risk factors.

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.