Parental Age and Risk of Lymphoid Neoplasms.

High parental age at childbirth has repeatedly been linked to childhood malignancies, while few studies have focused on the offspring's risk of adult cancer. In this population-based case-control study, we identified 32,000 patients with lymphoid neoplasms, diagnosed at ages 0-79 years during the period 1987-2011, and 160,000 matched controls in Sweden. Using prospectively registered data on their first-degree relatives, we evaluated the impact of parental age on the risk of lymphoid neoplasms by subtype. Overall, each 5-year increment in maternal age was associated with a 3% increase in incidence of offspring lymphoid neoplasms (hazard ratio = 1.03, 95% confidence interval: 1.02, 1.04). The association was similar for paternal age and present even among individuals older than 70 years of age at diagnosis. Stratified analyses further revealed that the association was limited to certain subtypes, mostly of indolent nature. Risks of chronic lymphocytic leukemia, follicular lymphoma, and mantle cell lymphoma were 5%-10% higher per 5-year increment in maternal age, but no associations were observed for acute lymphoblastic leukemia, plasma cell neoplasms, or diffuse large B-cell lymphoma. These findings indicated that prenatal genetic or epigenetic changes influence risk of adult lymphoid neoplasms and suggest a difference in this association between aggressive and indolent lymphoma subtypes.