Background: Recent studies have indicated an increase in young adulthood Hodgkin's disease incidence, particularly among females, since 1970. However, no studies have examined the long term trends and period-cohort patterns of Hodgkin's disease incidence.
Methods: The current study reported time trends and age-period-cohort patterns of Hodgkin's disease incidence during the period 1935-1992, with an emphasis on incidence rate changes among young adults, using data from the Connecticut Tumor Registry.
Results: A total of 4997 incidences of Hodgkin's disease were included in the study. The authors found that the incidence of Hodgkin's disease had increased among young adults age 20-44 years. Incidence had increased dramatically among females since 1970 but less significantly among males. These observed trends were primarily associated with nodular sclerosis histologic type. Age-period-cohort analyses indicated that these observed increases in young adults were cohort phenomena, suggesting possible changes in exposure to risk factors.
Conclusions: Currently identified major risk factors, including social status, Epstein-Barr virus infection, and human immunodeficiency virus infection, cannot adequately explain the observed trends. Analytical epidemiologic studies are urgently needed to identify risk factors that will not only elucidate the etiology of Hodgkin's disease but also explain the rapid increase in Hodgkin's disease incidence among young females.