UCLA

Childhood cancer is a complex group of diseases affecting children, causing significant physical, emotional, and financial burdens globally. Genetic predisposition, infections during pregnancy, and pharmaceutical exposures are potential risk factors for childhood cancer. Understanding childhood cancer is crucial for effective prevention and treatment strategies. This dissertation investigates the impact of maternal and child infections and pharmaceutical exposure during pregnancy on childhood cancer risk through population-based studies in Denmark and Taiwan.

The first study examined the effect of postnatal infection on childhood cancer risk using Danish nationwide registries from 1978 to 2016. The findings from this matched case-control study revealed a positive association between postnatal infections and various childhood cancers, including acute lymphoblastic leukemia (ALL), acute myeloid leukemia, non-Hodgkin's lymphoma, and central nervous system tumors (CNS).

The second study explored infection and antibiotic exposure during pregnancy using Taiwan's Maternal and Child Health Database and national health and cancer registries from 2004 to 2015. This cohort study unveiled moderate associations between infections during pregnancy and the risk of hepatoblastoma, accompanied by a discernible elevation in the risk of ALL. Antibiotic prescriptions during pregnancy, especially tetracyclines, increased the risk of childhood ALL, and certain antibiotics raised hepatoblastoma risk.

The third investigation focused on nitrosatable drug exposure during pregnancy employing a meticulous matched case-control study and analyzing data sourced from Danish nationwide registries spanning the years 1995 to 2016. The study found that nitrosatable drug prescription during pregnancy was potentially associated with the risk of offspring’s CNS and neuroblastoma.

The final study assessed acetaminophen exposure during pregnancy using the Taiwan population-based cohort from 2004 to 2017. Prolonged acetaminophen use throughout all trimesters was potentially associated with elevating the risk of medulloblastoma, hepatoblastoma, and bone tumors.

In summary, this dissertation sheds light on the impact of maternal and child infections and pharmaceutical exposure during pregnancy on childhood cancer risk. Utilizing rigorous population-based case-control and cohort studies in Denmark and Taiwan, this research enhances our understanding of etiological factors of childhood cancer. The findings highlight the need to investigate potential risk factors such as infections, antibiotics, nitrosatable drugs, and acetaminophen use during pregnancy to advance prevention strategies for childhood cancers.