Non-Hodgkin's lymphoma: An analysis of the Metropolitan Detroit SEER database

We evaluated incidence and survival trends of non-Hodgkin's lymphoma (NHL) in a large population-based cancer registry. Data regarding demographics, histology, incidence, and survival were obtained on all patients with NHL registered in the Metropolitan Detroit Cancer Surveillance System, a participant in the Surveillance Epidemiology and End Results (SEER) Program of the National Cancer Institute. Incidence and survival trends from 1973 through 1995 were evaluated and stratified based on age at diagnosis, sex, race, and tumor grade. There were 11,978 patients diagnosed with NHL and recorded in the Metropolitan Detroit SEER registry from 1973 to 1995. The age-adjusted incidence rate increased from 8.6 to 15.8 per 100,000, leading to an overall increase in incidence of 83% and an average annual increase of 3.2% per year. Incidence increased significantly (p < 0.05) over time in all age groups except the youngest (ages 0-19) and in all demographic groups studied. Incidence was highest in white men and lowest in black women. The incidence of both low-grade and intermediate/high-grade NHL increased significantly for each age group (p < 0.05) except the youngest (ages 0-19). In the oldest patients (70+ years), the incidence of intermediate/high-grade NHL was almost double that of low-grade NHL. Five-year relative survival increased from 64% (1973-1983) to 68% (1984-1991) for patients with low-grade NHL and from 40% to 44% for those with intermediate/high-grade NHL. The increase in relative survival was only seen in whites, however, with 5-year relative survival in blacks decreased from 53% (1973-1983) to 45% (1984-1991). In metropolitan Detroit, the current NHL epidemic affects all age groups except the very young (ages 0-19), both sexes, and both whites and blacks and is due to increases in the incidence of both low-grade and intermediate/high-grade NHL. Five-year survival rates have increased for whites but not for blacks.