title: Associations between plasma insulin-like growth factor proteins and C-peptide and quality of life in patients with metastatic colorectal cancer.
abstract: OBJECTIVE
  Predictors of quality of life (QOL) in patients with metastatic colorectal cancer are lacking. The insulin-like growth factor (IGF) family of proteins is associated with QOL in noncancer populations. We sought to study whether these proteins are associated with QOL in patients with colorectal cancer.
  
  
  METHODS
  We used a cohort of 526 patients with metastatic colorectal cancer treated with combination chemotherapy. Plasma samples of IGF-I, IGF-II, IGF binding protein-3, and C-peptide were collected before initiation of chemotherapy. QOL was measured by the uniscale instrument and the Symptom Distress Scale at baseline and throughout treatment.
  
  
  RESULTS
  Baseline plasma levels of IGF-I and IGF-II before initiation of chemotherapy were significantly associated with several important baseline QOL measures in patients with metastatic colorectal cancer. Patients with lower levels of IGF-I reported increased distress with regard to appearance, appetite, cough, and nausea intensity after adjustment for potential confounders. Similarly, decreased levels of IGF-II were predictive of worse quality related to appearance, appetite, fatigue, nausea frequency and intensity, pain frequency, and composite Symptom Distress Scale score. IGF binding protein-3 and C-peptide were not predictive of baseline QOL. Baseline biomarkers were not associated with subsequent changes in QOL during treatment. Higher body mass index was significantly associated with superior baseline QOL in several areas; nonetheless, the association of IGF-I and IGF-II with baseline QOL measures remained significant even after controlling for baseline body mass index.
  
  
  CONCLUSIONS
  Baseline plasma IGF-I and IGF-II are significantly associated with symptom distress. Whether this association is simply reflective of patient nutritional status and/or disease burden or represents an independent biological effect of IGFs on QOL remains uncertain. Nonetheless, these data suggest that molecular biomarkers may be useful predictors of QOL in cancer patients.
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA. jmeyerhardt@partners.org
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Meyerhardt
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Sloan
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Sargent
authors.forename: Richard M
authors.initials: RM
authors.lastname: Goldberg
authors.forename: Michael
authors.initials: M
authors.lastname: Pollak
authors.forename: Roscoe F
authors.initials: RF
authors.lastname: Morton
authors.forename: Ramesh K
authors.initials: RK
authors.lastname: Ramanathan
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Williamson
authors.forename: Brian P
authors.initials: BP
authors.lastname: Findlay
authors.forename: Charles S
authors.initials: CS
authors.lastname: Fuchs
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001066:Appetite; D014408:Biomarkers, Tumor / Q000097:blood*; D002096:C-Peptide / Q000097:blood*; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000523:psychology; D005221:Fatigue; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009325:Nausea; D009362:Neoplasm Metastasis; D017060:Patient Satisfaction; D011788:Quality of Life; D013002:Somatomedins / Q000032:analysis*; D013315:Stress, Psychological
chemical_list: D014408:Biomarkers, Tumor; D002096:C-Peptide; D013002:Somatomedins