title: Mammography performance in Oman: Review of factors influencing cancer yield and positive predictive value.
abstract: OBJECTIVE
  The aim of this study is to assess mammography performance in Oman by estimating the breast cancer rate and the positive predictive value (PPV) with the influence of some variables.
  
  
  METHODS
  This cross-sectional study was conducted on mammograms done in one of the three main breast imaging centers in Oman between January 2008 and July 2012. Diagnostic and screening groups were identified and assessed separately. Rate of abnormal mammograms, rate of breast cancer and the PPV were estimated according to Breast Imaging Reporting and Data System (BIRADS) score, presence of breast lump and patient's age.
  
  
  RESULTS
  Total of 653 mammograms were included, 254 diagnostic and 399 screening. Abnormal mammograms (BIRADS 4 and 5) form 31.9% of the diagnostic examinations compared with 6.8% of screening examinations. Breast cancer was present in 17.9% of the diagnostic compared with 1.0% of the screening group. The PPV of BIRADS 5 was 94.1%, and for BIRADS 4 was 37.1 and 26.7% for diagnostic and screening studies. Overall PPV for abnormal mammograms was 65.2% in the diagnostic and 26.7% in the screening group. Mammography PPV shows positive association with age (P = 0.039) while presence of breast lump has no significant effect on the PPV (P = 0.38).
  
  
  CONCLUSIONS
  BIRADS 5 score was found to have a high cancer yield making it a strong predictor of cancer. Different results were obtained in the diagnostic compared with screening mammography with higher rates of abnormal mammograms and breast cancer. Mammography performance should be better in the older women.
authors.affiliation: Department of Radiology, Khoula Hospital, Muscat, Oman.
authors.forename: Sawsan
authors.initials: S
authors.lastname: Taif
authors.affiliation: Department of Radiology, Khoula Hospital, Muscat, Oman.
authors.forename: Fatma
authors.initials: F
authors.lastname: Tufail
authors.affiliation: Department of Community Medicine, Baghdad College of Medicine, Baghdad, Iraq.
authors.forename: Ahmed Sameer
authors.initials: AS
authors.lastname: Alnuaimi
mesh_terms: D000328:Adult; D001940:Breast / Q000000981:diagnostic imaging; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D003430:Cross-Sectional Studies; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods / Q000706:statistics & numerical data; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D009850:Oman / Q000453:epidemiology
keywords: BIRADS; mammography; performance