title: Social networks and survival after breast cancer diagnosis.
abstract: BACKGROUND
  Evidence has been inconsistent regarding the impact of social networks on survival after breast cancer diagnosis. We prospectively examined the relation between components of social integration and survival in a large cohort of breast cancer survivors.
  
  
  METHODS
  Women (N=4,589) diagnosed with invasive breast cancer were recruited from a population-based, multi-center, case-control study. A median of 5.6 years (Interquartile Range 2.7-8.7) after breast cancer diagnosis, women completed a questionnaire on recent post-diagnosis social networks and other lifestyle factors. Social networks were measured using components of the Berkman-Syme Social Networks Index to create a measure of social connectedness. Based on a search of the National Death Index, 552 deaths (146 related to breast cancer) were identified. Adjusted hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards regression.
  
  
  RESULTS
  Higher scores on a composite measure of social connectedness as determined by the frequency of contacts with family and friends, attendance of religious services, and participation in community activities was associated with a 15-28% reduced risk of death from any cause (p-trend=0.02). Inverse trends were observed between all-cause mortality and frequency of attendance at religious services (p-trend=0.0001) and hours per week engaged in community activities (p-trend=0.0005). No material associations were identified between social networks and breast cancer-specific mortality.
  
  
  CONCLUSIONS
  Engagement in activities outside the home was associated with lower overall mortality after breast cancer diagnosis.
authors.affiliation: Cancer Prevention Program, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., M3-A410, Seattle, WA 98109-1024, USA.
authors.forename: Jeannette M
authors.initials: JM
authors.lastname: Beasley
authors.forename: Polly A
authors.initials: PA
authors.lastname: Newcomb
authors.forename: Amy
authors.initials: A
authors.lastname: Trentham-Dietz
authors.forename: John M
authors.initials: JM
authors.lastname: Hampton
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Ceballos
authors.forename: Linda
authors.initials: L
authors.lastname: Titus-Ernstoff
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Egan
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Holmes
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis / Q000401:mortality* / Q000523:psychology / Q000534:rehabilitation; D002277:Carcinoma / Q000175:diagnosis / Q000401:mortality* / Q000523:psychology / Q000534:rehabilitation; D016022:Case-Control Studies; D002423:Cause of Death; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D012944:Social Support; D012959:Socioeconomic Factors; D016019:Survival Analysis