Childhood exposures among mothers and Hodgkin's lymphoma in offspring.

BACKGROUND

Childhood exposures in mothers, signaled by number of older and younger siblings, have lifelong consequences for aspects of immune function. We hypothesized that these may influence young adult-onset Hodgkin's lymphoma (HL) risk in offspring.

MATERIALS AND

METHODS

Swedish registers identified 2028 cases of young adult onset HL (diagnosed between ages 15-39 years) up to 2012 among those born since 1958; and 18,374 matched controls. Conditional logistic regression was used to assess HL risk associated with number of older and younger siblings of mothers.

RESULTS

Having a mother with more than two older siblings is associated with lower HL risk, and the association is statistically significant for mothers with three or more siblings, compared with none. The adjusted odds ratios (and 95% confidence intervals) are 1.04 (0.93-1.16); 0.95 (0.81-1.10); and 0.81 (0.66-0.98) for one, two, and three or more older siblings, respectively. There is no association between number of mothers' younger siblings and HL risk.

CONCLUSIONS

Exposures during the childhood of mothers may influence young onset adult HL risk in offspring, perhaps through vertical transmission of infectious agents, or through other long-term influences on maternal immune function.