Genome-Wide Association Study of Pregnancy in Childhood Cancer Survivors: A Report from the Childhood Cancer Survivor Study

Gonadotoxic treatment-related infertility has a significant impact on quality of life in childhood cancer survivors. Genome-wide association analyses to delineate the risk of infertility in childhood cancer survivors have not been previously reported. Leveraging genotype data from a large survivor cohort, the Childhood Cancer Survivor Study (CCSS), we investigated the role of SNPs on future pregnancy or siring a pregnancy in survivors without pelvic, testicular, or brain radiation who had ever been married. We calculated sex-stratified hazard ratios, using Cox proportional hazards modeling, adjusting for birth cohort (before 1965 vs. 1965 or later) and doses of relevant chemotherapies; replication was attempted in the independent St. Jude Lifetime Cohort study (SJLIFE). In the CCSS cohort, nine SNPs were found to be suggestive (P < 10-7) or statistically significantly (P < 5 × 10-8) associated with pregnancy, however, none of the SNPs were replicated in SJLIFE. Cohorts differed based on the overall pregnancy rate, frequency of sterilizing procedures, and birth cohort. We were not able to replicate our findings of SNPs associated with pregnancy in childhood cancer survivors. Future attempts at replication should be considered in cohorts treated in a comparable era. In addition, understanding the role of genetics in fertility in childhood cancer survivors may be better approached using more advanced sequencing techniques.