All-cancer incidence and mortality in Pakistanis, Bangladeshis, and their descendants in England and Wales.

backgroundThis paper identifies differences in all-cancer incidence and mortality between Pakistani-born (PB), Bangladeshi-born (BB), their descendants, and the White British (WB) in England and Wales. Pakistanis and Bangladeshis are the most marginalised and disadvantaged groups in England and Wales yet, are found to have low cancer mortality and low all-cause mortality. Previous studies though have not looked at generational differences, applied individual-level data nor separated Pakistanis and Bangladeshis from each other and other Asian groups.

methodsWe use the Office for National Statistics Longitudinal Study of England and Wales which is a 1% representative sample of the population. We apply event history analysis on a study period from 1971 to 2016, following individuals from age 20 until a first cancer incidence, censoring at emigration or death. We observe 10,885,500 person-years and 71,926 cancer incidences for WB; 125,700 person-years and 295 events for PB; 53,900 person-years and 113 events for BB and 26,900 person-years and 24 events for descendants. Following incidence, we study a maximum of ten years until a death from cancer, or censoring. In this second analysis on mortality our sample has 329,700 person-years and 31,689 cancer deaths for WB; 1,200 person-years and 104 events for PB; 400 person-years and 50 events for BB and 100 person-years and 10 events for descendants.

resultsResults from the fully adjusted models show that the risk of cancer incidence is lower for PB, BB and descendants compared to the WB native group. Estimated hazard ratio (HR) equals 0.42 for PB (95% confidence interval (CI): 0.38-0.47), for BB HR is 0.38 (CI: 0.32-0.46) and, for descendants HR is 0.36 (CI: 0.24-0.54). Results for cancer mortality after incidence show HR for PB is 0.93 (CI: 0.76-1.12), for BB it is 0.95 (CI: 0.72-1.25) and for descendants HR equals 1.62 (CI: 0.87-3.02 - significant at 90%).

conclusionsUsing high quality representative data, we show that lower incidence of cancer and not better survival is the driver of the low cancer mortality previously found. This advantage persists across immigrant generations, but all-cancer mortality following incidence may be elevated for descendants.