Background: The incidence of non-Hodgkin lymphoma (NHL) has been rising in many regions and populations during the last few decades. Data from the Surveillance, Epidemiology, and End Results (SEER) Program show that age-adjusted rates of NHL increased through the 1980s but leveled off in the 1990s.
Methods: To determine whether the incidence of NHL stabilized in all population subgroups, particularly in age-defined groups with distinctive risks of NHL, the authors investigated trends in NHL incidence among persons aged 0-14 years, 15-24 years, 25-34 years, 35-44 years, 45-54 years, 55-64 years, 65-74 years, and > 75 years by gender and race using 1973-1998 data from the SEER Program, which covered approximately 10% of the U.S. population. Joinpoint regression was used to assess changes in trends across the period.
Results: NHL incidence trends changed significantly among males aged 25-54 years, in whom rates began to decrease (6-16% per year) in the middle to late 1990s, as well as among most whites aged > or = 55 years, in whom rate increases slowed from 3-4% to 1-2% per year in the late 1980s. Incidence trends were steady in other groups, with uniform increases among whites aged 15-24 years (2-3% per year), women aged 25-54 years (1-6% per year), and blacks aged > or = 55 years (2-4% per year). Although recent age specific incidence rates were generally higher in males compared with females and in whites compared with blacks, among males aged 25-54 years, rates were significantly higher in black males compared with white males.
Conclusions: There have been changes in the demographic groups impacted by NHL. The trends for human immunodeficiency virus probably are related to recent decreases in NHL incidence among males aged 25-54 years. The rate change in the older white population is unexplained but represents both an alleviation of the burden of NHL in this population and a potential opportunity to generate hypotheses regarding risk factors for the development of NHL.
Copyright 2002 American Cancer Society.