title: Breast cancer risk in rheumatoid arthritis: an update meta-analysis.
abstract: BACKGROUND
  The incidence of breast cancer in RA patients remains controversial. Thus we performed a meta-analysis to investigate the impact of RA on breast cancer.
  
  
  METHODS
  Published literature was available from PubMed, Embase, and Cochrane Library. Pooled standardized incidence rate (SIR) was computed by random-effect model analysis.
  
  
  RESULTS
  We identified 16 separate studies in the present study, in which the number of patients ranged from 458 to 84,475. We did not find the increased cancer risk in RA patients (SIR=0.86, 95% CI=0.72-1.02). However, subgroup analysis showed that breast cancer risk in RA patients was positively different in Caucasians (SIR=0.82, 95% CI=0.73-0.93) and non-Caucasians (SIR=1.21, 95% CI=1.19-1.23), respectively. In subgroup analysis by style, a reduced incidence was found in hospital-based case subjects (SIR=0.82, 95% CI=0.69-0.97). Similarly, subgroup analysis for adjusted factors indicated that in A3 (age and sex) and A4 (age, sex, and race/ethnicity) the risk was decreased (SIR=0.87, 95% CI=0.76-0.99; SIR=0.63, 95% CI=0.59-0.67).
  
  
  CONCLUSIONS
  The meta-analysis revealed no increased breast cancer risk in RA patients. However, in the subgroup analysis, the risk of breast cancer is increased in non-Caucasians patients with RA while it decreased in Caucasian population, hospital-based case subjects, and A3 group. Such relationship may provide preference for risk of breast cancer in different population.
authors.affiliation: School of Health Management, Anhui Medical University, 81 Meishan Road, Hefei, Anhui 230032, China.
authors.forename: Guo
authors.identifier: 0000-0002-8444-7285
authors.initials: G
authors.lastname: Tian
authors.affiliation: School of Health Management, Anhui Medical University, 81 Meishan Road, Hefei, Anhui 230032, China ; The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, Anhui 230022, China.
authors.forename: Jia-Ning
authors.initials: JN
authors.lastname: Liang
authors.affiliation: The Second Affiliated Hospital of Anhui Medical University, 678 Furong Road, Hefei, Anhui 230601, China.
authors.forename: Zhuo-Yun
authors.initials: ZY
authors.lastname: Wang
authors.affiliation: The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, Anhui 230022, China.
authors.forename: Dian
authors.identifier: 0000-0003-0902-5370
authors.initials: D
authors.lastname: Zhou
mesh_terms: D001172:Arthritis, Rheumatoid / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D005260:Female; D006801:Humans; D012307:Risk Factors; D044465:White People