Abstract 874: Predicted leukocyte telomere length and risk of germ cell tumors

Genetically predicted leukocyte telomere length (LTL) has been evaluated in a number of studies of childhood and adult cancer, with evidence that longer predicted LTL is associated with increased cancer risk. We use Mendelian Randomization (MR) to test whether genetically predicted LTL is associated with germ cell tumors (GCT) in pediatric, adolescent, and adult cases using six SNPs that are validated predictors of LTL. A seventh SNP in the validated genetic predictor of LTL, rs2736100, a variant on TERT, is associated with adult testicular GCT (TGCT); therefore, in our overall analysis, we removed this SNP to avoid violating MR assumptions. Pediatric GCT samples were obtained from a Children9s Oncology Group study and state biobank programs in Michigan and California. Genotyping array data were generated using the Illumina HumanCoreExome Beadchip. For each SNP, we estimated main effects for pediatric GCT within 610 complete case-parent trios using the transmission disequilibrium test. We did the same in an independent case-control dataset of 803 pediatric cases and 1,022 controls stratified by ancestry using multivariable logistic regression adjusted for sex, ancestry-specific principal components (PCs), and study site. Effect estimates were meta-analyzed and used to perform the MR analyses. In a separate sample of 396 cases and 1,589 matched controls from the UK Biobank, genotyping array data was used to evaluate the association between a polygenic risk score capturing genetically predicted LTL and TGCT in men Citation Format: Shannon S. Cigan, Ava C. Kelley, John J. Meredith, Erica K. Langer, Anthony J. Hooten, John A. Lane, Benjamin R. Cole, Nathan Pankratz, Jenny Poynter. Predicted leukocyte telomere length and risk of germ cell tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 874.