The incidence of chronic lymphocytic leukemia (CLL) in the Asian population is up to 10 times lower than that in Caucasians. Studies on CLL in Asian residents in North America may help to determine the relative genetic and environmental causes of such a difference. Computerized records of CLL incidence from the combined British Columbia (BC) databases (n = 2736) and the Hong Kong Cancer Registry (HKCR, n = 572) were traced. Ethnic Chinese cases of CLL in BC were identified (n = 35). The world age standardized rates (WASRs) of CLL (per 100 000) were calculated in BC (1.71), HK (0.28) and BC Chinese (0.4), respectively. Using standard incidence ratios (SIRs), the observed BC Chinese case number was comparable to the figure projected from HK rates (SIR 1.3, p = 0.1) but significantly lower than the figure following BC rates (SIR 0.22, p < 0.0001). The difference was maintained over both genders, in all age groups and through the years. Our data over three decades suggest that genetic factors outplay environmental factors to give lower CLL rates in Chinese.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.