title: Serum insulin-like growth factor I and subsequent risk of colorectal cancer among Japanese-American men.
abstract: Recent reports suggest that colorectal cancer is positively related to insulin-like growth factor I (IGF-I) and inversely related to insulin-like growth factor binding protein 3 (IGFBP-3). To evaluate these associations further and separately for colon and rectal cancer, the authors conducted a nested case-control study in a cohort of 9,345 Japanese-American men examined in Hawaii in 1971-1977. A total of 177 incident colon cancer cases and 105 incident rectal cancer cases were identified from 1972 to 1996. These patients' stored sera and those of 282 age-matched controls were measured for IGF-I and IGFBP-3. The adjusted mean level of IGF-I was higher in colon cancer cases than in controls (154.7 ng/ml vs. 144.4 ng/ml; p = 0.01). However, the multivariate odds ratio for the highest quartile compared with the lowest was just 1.8 (95% confidence interval: 0.8, 4.3). Adjusted mean IGF-I levels were similar between rectal cancer cases and their controls. For IGFBP-3, adjusted mean levels were lower for both colon and rectal cancer cases than for their matched controls, but the differences were not significant. The IGF-I results weakly support findings from other studies and suggest that there are differences in IGF-I findings between colon and rectal cancer cases. It is possible that IGF-related risk is confounded by other factors that may vary among different cohorts. Further research is needed to clarify these relations.
authors.affiliation: Japan-Hawaii Cancer Study, Kuakini Medical Center, Honolulu, HI 96817, USA. abe@kuakini.net
authors.forename: Abraham M Y
authors.initials: AM
authors.lastname: Nomura
authors.forename: Grant N
authors.initials: GN
authors.lastname: Stemmermann
authors.forename: James
authors.initials: J
authors.lastname: Lee
authors.forename: Michael N
authors.initials: MN
authors.lastname: Pollak
mesh_terms: D017668:Age of Onset; D000368:Aged; D001213:Asian / Q000706:statistics & numerical data; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000097:blood / Q000453:epidemiology; D015179:Colorectal Neoplasms / Q000097:blood* / Q000208:ethnology*; D006254:Hawaii / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood*; D007564:Japan / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012004:Rectal Neoplasms / Q000097:blood / Q000453:epidemiology; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D018972:Insulin-Like Growth Factor Binding Protein 3; D036341:Intercellular Signaling Peptides and Proteins; C065700:myotrophin