Comprehensively evaluating cancer survival in children with birth defects: a population-based assessment.

ABSTRACT

PURPOSE: Congenital malformations are strong risk factors for childhood cancer. Our objective was to determine whether cancer survival differs by birth defect status among Oklahoma children. METHODS: We used accelerated failure time models to estimate survival time ratios (SRs) and 95% confidence intervals (CIs), adjusted for maternal race/ethnicity and census tract-level poverty, among children diagnosed with cancer and born in Oklahoma from 1997 to 2012 (n = 971), by linking records from birth certificates, birth defects, and cancer registries. RESULTS: We observed decreased, though imprecise, survival time among survivors with any birth defect (SR 0.82, 95% CI 0.29, 2.31) or chromosomal defects (n = 24) (SR 0.43, 95% CI 0.06, 3.30) compared to those without birth defects. We observed no difference in survival time among children with non-chromosomal defects (SR 0.98, 95% CI 0.31, 3.12) compared to children with no birth defects. CONCLUSION: Our study did not identify significant differences in cancer survival for children with and without birth defects. Future studies should consider pooling data from multiple states to allow in-depth study of specific birth defects and cancer types and confirm whether survival differs by type and number of birth defects.