Malignant neoplasms of the lymphatic and haematopoietic system in Circumpolar Inuit

Malignancies of the lymphatic and haematopoietic system in Circumpolar Inuit were studied as part of an international collaboration combining results from cancer registries for Alaska, Canada and Greenland. Low risk was observed for all such malignancies, including non-Hodgkin lymphoma, Hodgkin's disease, multiple myeloma and the combined leukaemias. Standardized incidence ratios (SIRs) of non-Hodgkin lymphoma ranged from 0.3 to 0.5 based on comparison populations in Connecticut (USA), Canada and Denmark. SIR of Hodgkins's disease ranged from 0.1 to 0.2. Acute leukaemias accounted for 78% of all microscopically verified leukaemias and chronic leukaemias for 6%. No clear time trends were observed except for increasing rates of the combined leukaemias among women from the first to the second half of the study period. The epidemiology of haematologic and lymphoproliferative malignancies in Inuit is comparable to results from Chinese and Japanese populations in Asia and may reflect protective environmental or genetic factors for these malignancies.