Temporal and geographic variations of Waldenstrom macroglobulinemia incidence: a large population-based study.

BACKGROUND: Waldenstrom macroglobulinemia (WM) is a non-Hodgkin lymphoma (NHL) subtype. Little is known about the incidence and trends for this disease in the United States.

METHODS: Twenty-year data from the Surveillance, Epidemiology, and End Results (SEER) program were used for this study. SEER*Stat was used for data analysis.

RESULTS: Of the 95,797 cases of NHL diagnosed between 1988 and 2007 in 9 SEER registries, 1835 (1.9%) were new cases of WM. Median age at diagnosis of WM was 73 years. The overall annual age-adjusted incidence was 0.38 per 100,000 persons per year, which increased with age, ranging from 0.03 in patients aged <50 years to 2.85 in patients aged ≥80 years. The incidence of WM was higher in men (0.54) than in women (0.27; P < .001) and was higher in whites (0.41) than in African Americans (0.18) or other races (0.21; P < .05). The annual percentage change for the whole population was 1.01% (P > .05). The annual percentage change was 1.21% for whites (P < .05) and 0.80% (P > .05) for nonwhites. Significant annual percentage change increases were seen in the group aged 70 to 79 years (1.24%; P < .05) and in 3 geographic registries (P < .001).

CONCLUSIONS: Although the overall incidence of WM remained steady over time, significant increases in incidence were seen over the past 20 years in whites, in those aged 70 to 79 years, and in 3 geographic registry areas.