title: Challenges in interpreting cytokine biomarkers in biobehavioral research: a breast cancer exemplar.
abstract: OBJECTIVE
  This report extends the findings of a prior study comparing the level of plasma cytokines in women with breast cancer to those of women with a benign breast biopsy with the addition of a normal comparison group. The results of this three-group comparison are presented as background for discussing several methodologic challenges for biobehavioral research in inflammatory-based conditions.
  
  
  METHODS
  This study used a descriptive, cross-sectional design to compare the levels of plasma cytokines in women with breast cancer, women with a benign breast biopsy, and a normal comparison group. The levels of 17 cytokines were measured using multiplex bead array assays (Bio-Plex®). Data analysis included a variety of descriptive and graphical techniques to illustrate between-group differences in cytokine profiles.
  
  
  RESULTS
  The levels of plasma cytokines in the sample of 35 women who had recently been diagnosed with breast cancer, 24 women with a suspicious breast mass, who subsequently were found to have a benign breast biopsy, and 33 women in a normal comparison group present a background for discussing the implications of extreme between-group differences for biobehavioral nursing research. Both the levels of individual cytokines and their patterns were distinctly different in the three groups.
  
  
  CONCLUSIONS
  The exemplar presented from the three-group comparison has implications for planning biobehavioral nursing research in patients with conditions characterized by inflammation.
authors.affiliation: Department of Family and Community Health Nursing, Virginia Commonwealth University School of Nursing, Richmond, VA 23298, USA. delyon@vcu.edu
authors.forename: Debra
authors.initials: D
authors.lastname: Lyon
authors.forename: Jeanne
authors.initials: J
authors.lastname: Walter
authors.forename: Cindy L
authors.initials: CL
authors.lastname: Munro
authors.forename: Christine M
authors.initials: CM
authors.lastname: Schubert
authors.forename: Nancy L
authors.initials: NL
authors.lastname: McCain
mesh_terms: D015415:Biomarkers / Q000378:metabolism*; D001943:Breast Neoplasms / Q000276:immunology / Q000378:metabolism* / Q000523:psychology; D015400:Clinical Nursing Research / Q000379:methods*; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006801:Humans; D055809:Illness Behavior / Q000502:physiology*; D007249:Inflammation / Q000276:immunology / Q000378:metabolism; D008875:Middle Aged; D009369:Neoplasms / Q000276:immunology / Q000378:metabolism / Q000523:psychology; D013315:Stress, Psychological / Q000276:immunology / Q000523:psychology
chemical_list: D015415:Biomarkers; D016207:Cytokines