Waldenström's macroglobulinemia: incidence patterns in the United States, 1988-1994.

BACKGROUND

There are few data describing the epidemiologic aspects of Waldenström's macroglobulinemia (WM), a rare lymphoplasmaproliferative disorder.

METHODS

The authors evaluated the incidence of WM reported in 11 population-based cancer registries in the U.S.

RESULTS

A total of 624 cases were diagnosed between January 1, 1988 (when WM became reportable) and December 31, 1994. Age-adjusted incidence rates for WM (per 1 million person-years at risk) were 3.4 among males and 1.7 among females. The rates increased sharply with age, from 0.1 at age < 45 years to 36.3 at age 75+ years (males) and from 0.1 at age < 45 years to 16.4 at age 75+ years (females). The rates for WM were comparable to those for hairy cell leukemia, but considerably lower than those for multiple myeloma or chronic lymphocytic leukemia. Some geographic variation was evident, with age-adjusted rates among white males ranging from 2.2-7.8 across registries. There was no significant change in rates over the 7-year study period (P > 0.05). The markedly higher rates for WM among whites than blacks stand in contrast to multiple myeloma, which occurs twice as often among blacks.

CONCLUSIONS

This survey provides new data regarding the incidence patterns of WM in the U.S. However, further epidemiologic studies with biomarkers are needed to define the environmental, genetic, immunologic, and viral determinants of this rare but distinctive disorder.