Telomere Length and Genetic Variation in Telomere Maintenance Genes in Relation to Ovarian Cancer Risk

Background Telomeres protect chromosomal ends, shorten with cellular division, and signal cellular senescence but unchecked telomere attrition can lead to telomere dysfunction, upregulation of telomerase, and carcinogenesis. Shorter telomeres in peripheral blood leukocytes (PBLs) have been associated with elevated cancer risk. Further, genetic variants in and around the TERT gene have been implicated in carcinogenesis. Methods We measured relative telomere length (RTL) in PBLs of 911 cases and 948 controls from the New England Case Control Study, a population-based study of ovarian cancer. In addition, we assessed germline genetic variation in five telomere maintenance genes among 2112 cases and 2456 controls from the New England Case Control Study and the Nurses’ Health Study, a prospective cohort study. Odds ratios and 95% confidence intervals were estimated using logistic regression. Results Overall, we observed no differences in telomere length between cases and controls. Compared to women with RTL in the longest tertile, women with RTL in the shortest tertile had no increase in risk (OR=1.01, 95% CI: 0.80, 1.28). However, several SNPs in the TERT gene, including RS2736122, RS4246742, RS4975605, RS10069690, RS2736100, RS2853676, RS7726159, were significantly associated with ovarian cancer risk. We observed a significant gene-level association between TERT and ovarian cancer risk (p=0.00008). Conclusion Our observations suggest genetic variation in the TERT gene may influence ovarian cancer risk, but the association between average telomere length in PBLs and ovarian cancer remains unclear. Impact The role of telomeres in ovarian carcinogenesis remains unsettled and warrants further investigation.