Maternal autoimmune disease and its association with childhood cancer: A population-based case-control study in Denmark

Background: Autoimmune diseases have been linked to an increased risk of pregnancy-related complications. A family history of autoimmune diseases may be related to the risk of childhood cancer based on similar histocompatibility antigens. We utilized data from national registries in Denmark to examine associations between maternal autoimmune disease and cancer in their offspring. Methods: We linked data from several national registries in Denmark to identify childhood cancer cases in children <20 years diagnosed between 1977 to 2016. Controls were selected from the Central Population Register and matched to cases by birth year and sex (25:1). Mothers with autoimmune disease diagnosed in pregnancy or prior were identified from the National Patient Register. Multivariable conditional logistic regression analyses were used to estimate associations between maternal autoimmune diseases and childhood cancer in offspring. Results: Autoimmune diseases (all types) were positively associated with all childhood cancers combined (Odds Ratio (OR) = 1.25, 95% CI 1.06, 1.47), acute lymphoblastic leukemia (OR =1.52, 95% CI 1.09, 2.13), Burkitt lymphoma (OR = 2.69, 95% CI 1.04, 6.97), and central nervous system tumors (OR = 1.45, 95% CI 1.06, 1.99), especially astrocytoma (OR = 2.27, 95% CI 1.36, 3.77) and glioma (OR = 1.75, 95% CI 1.13, 2.73). When we examined mothers with rheumatoid arthritis, we observed an increased association for all cancers (OR = 2.15, 95% CI 1.40, 3.30), acute lymphoblastic leukemia (OR = 3.55, 95% CI 1.69, 7.47), and central nervous system tumors (OR = 2.91, 95% CI 1.46, 5.82), especially glioma (OR = 3.58, 95% CI 1.40, 9.18) in offspring. Conclusion: There is a positive association between maternal autoimmune disease and childhood cancer. This association is especially prominent in the offspring of women with rheumatoid arthritis.