Abstract A63: Influence of in utero maternal and child factors on cord blood leukocyte telomere length and possible differences by race: Clues to the racial disparity in prostate cancer?

Abstract

Abstract Background: The racial disparity in the prostate cancer incidence rate is among the greatest across all cancer sites. Further, African-American men tend to have more aggressive prostate cancer than white men. Modifiable factors measured in adulthood that may explain this disparity have not been found, despite extensive study. Whether racial differences early in life, including in utero, may account for this disparity is understudied. Shorter prostate cell telomeres, repetitive sequences that protect the ends of the chromosomes, are associated with a higher risk of aggressive prostate cancer and with poor prostate cancer outcomes. Telomeres shorten with each round of cell replication, and with oxidative damage, and thus, may serve as indicators of cell proliferation and cumulative exposures to oxidants. Using telomere length in umbilical cord blood leukocytes as a surrogate for prostate cell telomere length, we investigated the association of in utero maternal and child factors with telomere length, and whether telomere length differences between African-American and white males at birth may explain some of the racial disparity in prostate cancer. Methods: In 2004–2005, venous umbilical cord blood samples were collected from 38 African-American and 38 white male neonates, along with maternal and child characteristics from the Johns Hopkins Hospital. Eligibility criteria were: full-term birth (37-42 weeks), normal range birth weight (2500-4000 g), African-American or white, no pregnancy complications, and no maternal use of hormonal medications during pregnancy. Delivery room nurses completed a standardized form on maternal age, and parity, birth and placental weights, and race. Relative telomere length was measured by quantitative PCR from extracted buffy coat DNA. Using linear regression, we estimated geometric mean telomere length and 95% confidence intervals (CI) and tested for differences by race. Results: African-American neonates had statistically significantly lower birth and placental weights (child factors) than white neonates. African-American mothers were statistically significantly younger and had higher parity (maternal factors) than white mothers. However, neither maternal nor child factors were associated with telomere length adjusting for race or when stratifying by race (all p-trend>0.4). African-American neonates (6.60 kb, 95% CI 6.02-7.23 kb) had longer cord blood leukocyte telomeres than white neonates (6.43 kb, 95% CI 5.87-7.05 kb), although this difference was not statistically significant (p=0.7). The results were unchanged after adjusting for maternal or for child factors. Conclusion: Contrary to our hypotheses, maternal and child factors were not associated with cord blood leukocyte telomere length and cord blood leukocyte telomere length was not shorter in African-American than white male neonates. FUNDING: T32 CA0093140, DOD W81XWH-06-1-0052, U54 (Hopkins CA091409) and U54 (Howard CA091431). Citation Format: Kari A. Weber, Christopher M. Heaphy, Sabine Rohrmann, Beverly Gonzalez, Jessica L. Bienstock, Tanya Agurs-Collins, Elizabeth A. Platz, Alan K. Meeker. Influence of in utero maternal and child factors on cord blood leukocyte telomere length and possible differences by race: Clues to the racial disparity in prostate cancer? [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr A63.