title: Mean telomere length and risk of incident colorectal carcinoma: a prospective, nested case-control approach.
abstract: Recent studies have shown telomere length shortening in colorectal carcinoma (CRC). However, to date, no prospective, epidemiologic data are available on examining mean leukocyte telomere length as a risk predictor. Using leukocyte DNA samples collected at baseline in a prospective cohort of 14,916 initially healthy American men, we examined the relationship of mean telomere repeat copy number to single gene copy number (T/S ratio), using a modified quantitative PCR protocol, among 191 incident CRC cases (all white males), matched to 306 controls by age, smoking status, and length of follow-up. An inverse correlation between T/S ratio and age was observed in our sample population (P = 0.038). However, the T/S ratios were similar between cases and controls (P = 0.650). Furthermore, in a multivariable adjusted analysis, we found no evidence for an association of the observed T/S ratios with CRC risk (adjusted odds ratio, 1.249; 95% confidence interval, 0.863-1.808; P = 0.238). In summary, the present investigation found no evidence for an association of leukocyte mean telomere length with risk of incident CRC and further suggests that leukocyte mean telomere length may not be a useful indicator for risk assessment.
authors: Center for Cardiovascular Disease Prevention, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA. rzee@rics.bwh.harvard.edu
authors: Robert Y L
authors: RY
authors: Zee
authors: Amy J
authors: AJ
authors: Castonguay
authors: Nathaniel S
authors: NS
authors: Barton
authors: Julie E
authors: JE
authors: Buring
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics*; D006801:Humans; D007962:Leukocytes / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D016615:Telomere / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor