title: Telomere length is a prognostic factor for overall survival in colorectal cancer.
abstract: OBJECTIVE
  The aim of this study was to determine whether telomere length is an independent prognostic factor for the prevention and survival of colorectal cancer.
  
  
  METHODS
  Terminal restriction fragment (TRF) length was determined by Southern blot in tumours and paired normal tissue samples from 147 patients with sporadic colorectal cancer who had undergone surgery. The TRF length ratio (TRFLR) was determined as the ratio between the length of the patient's tumour and normal tissue.The classification and regression tree technique was used to determine optimal cut-off values (≤ 1 or > 1).
  
  
  RESULTS
  Mean TRF length was 6.79 Kbp (1.19-13.99) in tumour tissue and 7.81 Kbp (3.63-15.70) in normal mucosa (P < 0.001). Mean TRFLR was 0.88. Telomere length and telomere length ratio were not correlated with any clinicopathological factors. In univariate analysis, overall survival was related to N stage (lymph node +/-; P = 0.002), TNM classification (P = 0.019) and TRFLR (≤ 1 or > 1; P = 0.014). In multivariate analysis, overall survival was significantly associated with TRFLR and N stage. Colorectal cancer patients with TRFLR ≤ 1 and negative lymph node involvement had a higher overall survival rate.
  
  
  CONCLUSIONS
  Telomere length ratio is an independent prognostic factor for survival in colorectal cancer patients, and the telomere lengths in the normal and tumour mucosa of the same patient present with parallel behaviour.
authors.affiliation: Department of Medicine, Medical School, Lleida, Lleida, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Valls
authors.forename: C
authors.initials: C
authors.lastname: Piñol
authors.forename: J M
authors.initials: JM
authors.lastname: Reñé
authors.forename: J
authors.initials: J
authors.lastname: Buenestado
authors.forename: J
authors.initials: J
authors.lastname: Viñas
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D000368:Aged; D015139:Blotting, Southern; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D004273:DNA, Neoplasm; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D059505:Telomere Homeostasis
chemical_list: D004273:DNA, Neoplasm