Time Trends and Sex Patterns in Hodgkin’s Disease Incidence in Canada, 1970–1995

Abstract

To examine time trends and sex patterns in Hodgkin's disease incidence in Canada, from 1970 through 1995. In addition to analyses of the secular trends and sex ratio in incidence rates, age-period-cohort models were fitted to estimate the effects on the trends. Age-specific male/female incidence rate ratios were examined for the disease and for its two major histologic subtypes. The overall age-adjusted incidence rate of Hodgkin's disease decreased significantly in males (3.5 per 100,000 in 1970-71 to 2.8 in 1994-95) but only slightly in females (2.4 per 100,000 to 2.3). There was a significant increase in the incidence among females aged 10-29 and among males aged 10-24, but a dramatic decrease among older ages. Age-period-cohort modelling showed that birth cohort and period effects were responsible for the observed trends in males and females, respectively. The risk factors responsible for Hodgkin's disease are different in females and males. Reproductive factors are likely to be associated with the occurrence of the disease in young women.