title: Evidence of associations between cytokine gene polymorphisms and quality of life in patients with cancer and their family caregivers.
abstract: OBJECTIVE
  To identify latent classes of individuals with distinct quality-of-life (QOL) trajectories, to evaluate for differences in demographic characteristics between the latent classes, and to evaluate for variations in pro- and anti-inflammatory cytokine genes between the latent classes.
  
  
  METHODS
  Descriptive, longitudinal study.
  
  
  METHODS
  Two radiation therapy departments located in a comprehensive cancer center and a community-based oncology program in northern California.
  
  
  METHODS
  168 outpatients with prostate, breast, brain, or lung cancer and 85 of their family caregivers (FCs).
  
  
  METHODS
  Growth mixture modeling (GMM) was employed to identify latent classes of individuals based on QOL scores measured prior to, during, and for four months following completion of radiation therapy. Single nucleotide polymorphisms (SNPs) and haplotypes in 16 candidate cytokine genes were tested between the latent classes. Logistic regression was used to evaluate the relationships among genotypic and phenotypic characteristics and QOL GMM group membership.
  
  
  METHODS
  QOL latent class membership and variations in cytokine genes.
  
  
  RESULTS
  Two latent QOL classes were found: higher and lower. Patients and FCs who were younger, identified with an ethnic minority group, had poorer functional status, or had children living at home were more likely to belong to the lower QOL class. After controlling for significant covariates, between-group differences were found in SNPs in interleukin 1 receptor 2 (IL1R2) and nuclear factor kappa beta 2 (NFKB2). For IL1R2, carrying one or two doses of the rare C allele was associated with decreased odds of belonging to the lower QOL class. For NFKB2, carriers with two doses of the rare G allele were more likely to belong to the lower QOL class.
  
  
  CONCLUSIONS
  Unique genetic markers in cytokine genes may partially explain interindividual variability in QOL.
  
  
  CONCLUSIONS
  Determination of high-risk characteristics and unique genetic markers would allow for earlier identification of patients with cancer and FCs at higher risk for poorer QOL. Knowledge of these risk factors could assist in the development of more targeted clinical or supportive care interventions for those identified.
authors.affiliation: School of Nursing, Queensland University of Technology in Australia.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Alexander
authors.affiliation: School of Nursing, University of California, San Francisco (UCSF).
authors.forename: Bruce
authors.initials: B
authors.lastname: Cooper
authors.affiliation: School of Nursing, University of California, San Francisco (UCSF).
authors.forename: Steven M
authors.initials: SM
authors.lastname: Paul
authors.affiliation: School of Nursing, University of California, San Francisco (UCSF).
authors.forename: Claudia
authors.initials: C
authors.lastname: West
authors.affiliation: School of Nursing, Queensland University of Technology.
authors.forename: Patsy
authors.initials: P
authors.lastname: Yates
authors.affiliation: School of Nursing at UCSF.
authors.forename: Kord M
authors.initials: KM
authors.lastname: Kober
authors.affiliation: School of Nursing at UCSF.
authors.forename: Bradley E
authors.initials: BE
authors.lastname: Aouizerat
authors.affiliation: School of Nursing at UCSF.
authors.forename: Christine
authors.initials: C
authors.lastname: Miaskowski
mesh_terms: D000367:Age Factors; D000368:Aged; D017028:Caregivers / Q000523:psychology*; D015897:Comorbidity; D016207:Cytokines / Q000235:genetics* / Q000502:physiology; D005006:Ethnicity / Q000235:genetics; D005191:Family Characteristics; D005260:Female; D005500:Follow-Up Studies; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D005838:Genotype; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D007249:Inflammation / Q000453:epidemiology / Q000235:genetics / Q000523:psychology; D008297:Male; D008875:Middle Aged; D008913:Minority Groups; D008962:Models, Theoretical; D009369:Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000451:nursing / Q000523:psychology* / Q000532:radiotherapy; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D011788:Quality of Life; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D012307:Risk Factors
chemical_list: D016207:Cytokines
keywords: cytokines; family caregivers; genetics; growth mixture modeling; quality of life; radiation therapy