| Popis: |
Prenatal and early childhood exposures are potential risk factors for childhood cancers. Previous studies that have assessed these factors have relied on self-reports or are characterized by inconsistent findings. In addition, the available epidemiologic research investigating the association between childhood cancer and infections is sparse. The purpose of this dissertation was to investigate prenatal, maternal, birth, and parental birth factors that may be associated with childhood cancers using the Utah Population Database (UPDB). Furthermore, this dissertation also examined the potential relationship between infections and childhood leukemia, lymphoma, and central nervous system (CNS) tumors. A population-based case-control study design was utilized in investigating these relationships. Large-for-gestational age (LGA) birth weight was associated with an increased risk for childhood lymphoma (OR=1.59, 95%CI: 1.08 - 2.33). An overall dose response was observed between birth weight-for-gestational age (BWGA) and childhood CNS cancer risk (p=0.020). High birth weight newborns and childhood CNS cancer risk were associated with high birth weight parents (OR=3.11, 95% CI 1.02 - 9.55). Additionally, an overall dose response was observed between maternal BWGA and childhood CNS cancer risk (p=0.048). The risk of childhood lymphoma was associated with the following infection-related diagnosis groups: acute respiratory infections (OR=2.15, 95% CI: 1.39 - 3.31), pneumonia or influenza (OR=2.61, 95% CI: 1.10 - 6.18), and sweating iv fever (OR=3.56, 95% CI: 1.66 - 7.66). Dose response relationships were also observed between the number of infections and childhood lymphoma risk, including viral or respiratory disease (p=0.014). Furthermore, the risk of childhood lymphoma associated with sweating fever further increased in magnitude when limiting diagnoses to those that occurred within the first year of life (OR 6.53, 95% CI: 1.45 - 29.53). Having a tonsillectomy or adenoidectomy was associated with an increase in the risk of childhood leukemia (OR=2.57, 95% CI: 1.33 - 4.61). Finally, individuals who had undergone a myringotomy or tympanostomy were at a greater risk for childhood lymphoma (OR=3.90, 95% CI: 1.26 - 12.05). Our findings suggest that the prenatal growth environment and repeated exposure to common infections, particularly early in life, may play an important role in the etiology of childhood cancers. |
