Cancer surveillance series: Non-Hodgkin's lymphoma incidence by histologicsubtype in the United States from 1978 through 1995

Background: Clinical investigations have shown prognostic heterogeneity wit hin the non-Hodgkin's lymphomas (NHLs) according to histology, but few desc riptive studies have considered NHLs by subgroup. Our purpose is to assess the demographic patterns and any notable increases in population-based rate s of different histologic subgroups of NHL, Methods: Using data collected b y the Surveillance, Epidemiology, and End Results Program of the National C ancer Institute, we calculated incidence rates for the major clinicopatholo gic categories of NHL by age, race, sex, geographic area, and time period. Results: Among the 60 057 NHL cases diagnosed during the period from 1978 t hrough 1995, total incidence (per 100 000 person-years) was 17.1 and 11.5 a mong white males and females, respectively, and 12.6 and 7.4 among black ma les and females, respectively. However, rates for follicular NHLs mere two to three times greater among whites than among blacks, with little sex vari ation. Blacks demonstrated much higher incidence than whites for peripheral T-cell NHL, with the incidence rates higher in males than in females. For other NHL subgroups, the incidence rates for persons less than 60 years of age were generally higher among males than among females, with little racia l difference; at older ages, the rates mere higher among whites than among blacks, with little sex difference. High-grade NHL was the most rapidly ris ing subtype, particularly among males. Follicular NHL increased more rapidl y in black males than in the other three race/sex groups. Overall, the broa d categories of small lymphocytic, follicular, diffuse, high-grade, and per ipheral T-cell NHL emerged as distinct entities with specific age, sex, rac ial, temporal, and geographic variations in rates, Conclusions: Findings fr om our large, population-based study reveal differing demographic patterns and incidence trends according to histologic group. Future descriptive and analytic investigations should evaluate NHL risks according to subtype, as defined by histology and new classification criteria.