Different time trends by gender for the incidence of Hodgkin's lymphoma among young adults in the USA: a birth cohort phenomenon.

OBJECTIVES: Hodgkin's lymphoma (HL) is one of the most common cancers among young adults. We investigated the time trends for HL among the 20-44 age group in the USA by gender to identify the potential factors accounting for the incidence trends.
METHODS: Using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program for 1973-2010, we conducted age-period-cohort modeling to evaluate birth cohort patterns on incidence trends of HL over time.
RESULTS: For all races combined, the age-adjusted incidence patterns were similar to that of whites. The birth cohort patterns for whites and all races were similar, but the patterns differed according to gender. Specifically, except for the 1970-1975 birth cohort, all other birth cohorts showed an increasing birth cohort trend for females. Conversely, there was a decreasing cohort trend in males beginning in the 1960 birth cohort regardless of the assumptions of the period effect.
CONCLUSION: The established risk factors for HL can seemingly not explain the gender disparities of the cohort pattern, which necessitates further analytical epidemiological studies to explore the risk factors for this disease with respect to potential differences by gender and by histological subtype.