A descriptive analysis of congenital anomalies and childhood cancer in Oklahoma

Introduction: Several data-linkage studies found an association between congenital anomalies and childhood cancer. However, this linkage has not been done in Oklahoma using the existing birth defects and cancer registries. The results of this linkage may generate hypotheses about common pathways of congenital anomalies and cancer. We aimed to understand the process of data-linkage between these registries and determine if there was an association between congenital anomalies and childhood cancer. Methods: Data were obtained from the Oklahoma State Department of Health (OSDH) from the Oklahoma Birth Defects Registry (OBDR), Oklahoma Central Cancer Registry (OCCR), and Vital Statistics from 1997–2009. Children without congenital anomalies were identified from a random sample of all births and matched on birth year with a ratio of 4:1 to children with anomalies. We linked the databases and assessed the relationship between congenital anomalies and childhood cancer using modified Poisson regression. Results: Ninety-one percent of those in the OBDR linked to birth certificates. Fifty-five percent of those in OCCR linked to the matched set of OBDR and random sample of birth certificates. We found that children with congenital anomalies had 4.26 times higher risk of childhood cancer than children without congenital anomalies (95% CI: 3.14, 5.76). Discussion: Because this is the first linkage of this nature in Oklahoma, the process of working among different departments within OSDH was important and innovative. This study provided an opportunity to work with the health department and contribute to the literature regarding the association between congenital anomalies and childhood cancer.