title: Plasma C-reactive protein and risk of breast cancer in two prospective studies and a meta-analysis.
abstract: BACKGROUND
  C-reactive protein (CRP) has been evaluated as a risk factor for breast cancer in epidemiologic studies. However, results from prospective studies are inconsistent.
  
  
  METHODS
  We evaluated the association using prediagnostic blood samples in a case-control study nested within the Nurses' Health Study (NHS) and the full cohort of the Women's Health Study (WHS). A total of 943 cases in the NHS and 1,919 cases in the WHS contributed to the analysis. Conditional logistic regression and Cox proportional hazards model were used in the NHS and WHS, respectively. We pooled our results with prior prospective studies using random effect meta-analysis.
  
  
  RESULTS
  In the NHS, higher CRP levels were associated with a suggestively increased risk of breast cancer [quintile 5 vs. 1: relative risk (RR), 1.27; 95% confidence interval (CI), 0.93-1.73; Ptrend = 0.02]; results did not vary significantly by tumor invasiveness or hormone receptor status. However, no association was observed in the WHS for overall risk (quintile 5 vs. 1: RR, 0.89; 95% CI, 0.76-1.06; Ptrend = 0.38) or by tumor invasiveness or hormone receptor status. The meta-analysis (including 5,371 cases from 11 studies) showed a modestly increased risk among women in the highest versus lowest categories of CRP (RR, 1.26; 95% CI, 1.07-1.49).
  
  
  CONCLUSIONS
  Existing data from prospective studies suggest that CRP, a nonspecific marker of inflammation, is modestly positively associated with breast cancer risk.
  
  
  CONCLUSIONS
  Our findings provide support to the concept that inflammation can influence breast cancer development.
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, Massachusetts. junw@schoolph.umass.edu.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts. Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts.
authors.forename: I-Min
authors.initials: IM
authors.lastname: Lee
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts. Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Shelley S
authors.initials: SS
authors.lastname: Tworoger
authors.affiliation: Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts. Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts. Department of Ambulatory Care and Prevention, Harvard Medical School, Boston, Massachusetts.
authors.forename: Julie E
authors.initials: JE
authors.lastname: Buring
authors.affiliation: Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts. Center for Cardiovascular Disease Prevention, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Ridker
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts. Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts.
authors.forename: Bernard
authors.initials: B
authors.lastname: Rosner
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, Massachusetts. Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts. Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Hankinson
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000097:blood* / Q000473:pathology; D002097:C-Reactive Protein / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D002097:C-Reactive Protein