Age variation in Hodgkin's disease risk factors in older women: Evidence from a population-based case-control study

Hodgkin's disease (HD), which affects all age groups, has been associated with childhood social class, particularly among adults under age 40. Little is known about social class risk factors in older adults, and the few existing studies have conflicting findings. As part of a population-based case-control study of HD in women, we examined social class risk factors by diagnostic age groups (45-54 years and 55-79 years) corresponding to incidence patterns and by histologic subtypes based on a uniform pathologic review. Among women ages 45-54, cases were more likely to be Catholic, to have lower income and to be taller than controls. Among women ages 55-79, cases tended to have come from small or large childhood households, lived in single-family childhood housing, and had a single rather than shared bedroom at age 11. For the nodular sclerosis (NS) histologic subtype, similar age differences in risk factors were apparent. Comparisons between the NS and non-NS subtypes in women ages 55-79 identified some common risk factors (single-family childhood home, single bedroom at age 11) but others specific to one subtype (childhood household size, adult height for NS; lower maternal education for non-NS). Thus, some social class associations with RD differed between middle-aged and older women, as well as between these groups and younger adults, while others were shared across age groups. Risk also was associated with both higher and lower childhood social class in middle-aged and older women, in contrast with previous findings. None of these patterns was explained entirely by histologic subtype but may reflect age and histology subtype variation in the HD-EBV association.