Using cancer registry data, we show that although South Asians have lower rates of cancer than the rest of the population, this is changing with age and time. Younger South Asians, particularly children, are at increased risk. While generally cancer rates have fallen over the last decade, they are increasing among South Asians. Cancer incidence rates in the UK have been reported to be much lower for South Asians (Indian, Pakistani and Bangladeshi) than the rest of the population (Winter et al, 1999). However, there has been little report on recent trends in cancer among South Asians in the UK. In order to explore recent cancer incidence trends, we used 1990 -1999 cancer registry data for Leicester, UK, a city where 22% of residents classified themselves as South Asian in the 1991 census.
MATERIALS AND METHODSData were obtained from Trent Cancer Registry on all registrations of cancer diagnosed between 1 January 1990 and 31 December 1999, where the patient was a Leicester resident at diagnosis. Since routine ethnicity data were not available for all patients, individuals were classified as South Asian or non-South Asian based on forename and surname. Software was used to do this (Cummins et al, 1999), but accuracy was increased by visual inspection of the data. Deprivation is often a confounder in studies of ethnicity since they are closely related. There have been shown to be trends in incidence with deprivation for various cancer sites (Pollock and Vickers, 1997) so it was important to take account of deprivation in the analyses of cancer incidence. Therefore, the Townsend Index (Townsend et al, 1988) was used to assess the level of deprivation of the patient's area of residence. The local research ethics committee approved the study.Data were analysed for all cancers combined (all ages) and then for five common cancer sites (patients age 30 years and over): colorectal, head and neck, breast, lung and prostate. Electoral ward level population estimates were obtained from the 1991 census (by sex, ethnicity and 5-year age bands) and aggregated by deprivation tertile in order to calculate incidence rates. Variation in incidence rates by ethnicity, deprivation tertile, age and year of diagnosis (and any interactions between them) was explored using Poisson regression, separately for men and women. Firstly, a model was fitted to estimate the incidence rate ratio (IRR) for South Asians compared with non-South Asians for each age group, adjusting for deprivation tertile, and an interaction between ethnicity and age group was fitted to explore differential trends with age (Table 1). An interaction between time period (1990 -1994 and 1995 -1999) and ethnicity was then included to compare changes in incidence over time between South Asians and non-South Asians (Table 2). Interactions with deprivation were also explored.
RESULTSOut of 12 128 cancer cases identified, 862 were classified as occurring in South Asians (7%). South Asians (median age 61.5 years) were younger than non-South Asians (median age 71.9 years).Overa...
