Geographical variation in the incidence of the leukemias and lymphomas.

Despite the incomparability in the reporting of leukemia and lymphoma incidence among populations and the relative rarity of these diseases, real differences in rates are discernible from available data. In general, the incidence of each of the leukemias and lymphomas is lower in Japan than in other Pacific rim populations whose rates are known. Particularly striking is the low incidence of CLL in Japan. Among Japanese in Hawaii, rates of some of these cancers (lymphosarcoma, CML) approach those of whites, whereas rates of other cancers (Hodgkin's disease, multiple myeloma, ALL, CLL, and AML) more closely resemble those of native Japanese. The number of Chinese living in countries served by population-based cancer reporting systems is too small for any firm conclusions to be made about leukemia and lymphoma incidence in this group. The incidence of these diseases in certain other nonwhite Pacific rim residents (i.e., Mexican Americans, blacks, and Maoris) is, by and large, similar to that of whites.