title: Insulin-like Growth Factor-1, IGF-binding Protein-3, C-peptide and Colorectal Cancer: a Case-control Study.
abstract: BACKGROUND
  Insulin-like growth factor peptides play important roles in regulating cell growth, cell differentiation, and apoptosis, and have been demonstrated to promote the development of colorectal cancer (CRC).
  
  
  OBJECTIVE
  To examine the association of insulin-related biomarkers including insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3) and C-peptide with CRC risk and assess their relevance in predictive models.
  
  
  METHODS
  The odds ratios of colorectal cancer for serum levels of IGF-1, IGFBP-3 and C-peptide were estimated using unconditional logistic regression models in 100 colorectal cancer cases and 100 control subjects. Areas under the receiving curve (AUC) and integrated discrimination improvement (IDI) statistics were used to assess the discriminatory potential of the models.
  
  
  RESULTS
  Serum levels of IGF-1 and IGFBP-3 were negatively associated with colorectal cancer risk (OR=0.07, 95%CI: 0.03-0.16, P for trend <.01, OR=0.06, 95%CI: 0.03-0.15, P for trend <.01 respectively) and serum C-peptide was positively associated with risk of colorectal cancer (OR=4.38, 95%CI: 2.13-9.06, P for trend <.01). Compared to the risk model, prediction for the risk of colorectal cancer had substantially improved when all selected biomarkers IGF-1, IGFBP-3 and inverse value of C-peptide were simultaneously included inthe reference model [P for AUC improvement was 0.02 and the combined IDI reached 0.166% (95 % CI; 0.114-0.219)].
  
  
  CONCLUSIONS
  The results provide evidence for an association of insulin-related biomarkers with colorectal cancer risk and point to consideration as candidate predictor markers.
authors.affiliation: Department of Preventive Medicine, Kangwon National University School of Medicine, Korea E-mail : sangahlee@kangwon.ac.kr.
authors.forename: Joshi
authors.initials: J
authors.lastname: Pankaj
authors.forename: Joshi Rakhi
authors.initials: JR
authors.lastname: Kumari
authors.forename: Wj
authors.initials: W
authors.lastname: Kim
authors.forename: Sang-Ah
authors.initials: SA
authors.lastname: Lee
mesh_terms: D000368:Aged; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002096:C-Peptide / Q000378:metabolism*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016017:Odds Ratio; D011379:Prognosis; D012307:Risk Factors; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D002096:C-Peptide; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I