title: Breast cancer risk prediction and mammography biopsy decisions: a model-based study.
abstract: BACKGROUND
  Controversy continues about screening mammography, in part because of the risk of false-negative and false-positive mammograms. Pre-test breast cancer risk factors may improve the positive and negative predictive value of screening.
  
  
  OBJECTIVE
  To create a model that estimates the potential impact of pre-test risk prediction using clinical and genomic information on the reclassification of women with abnormal mammograms (BI-RADS3 and BI-RADS4 [Breast Imaging-Reporting and Data System]) above and below the threshold for breast biopsy.
  
  
  METHODS
  The current study modeled 1-year breast cancer risk in women with abnormal screening mammograms using existing data on breast cancer risk factors, 12 validated breast cancer single-nucleotide polymorphisms (SNPs), and probability of cancer given the BI-RADS category. Examination was made of reclassification of women above and below biopsy thresholds of 1%, 2%, and 3% risk. The Breast Cancer Surveillance Consortium data were collected from 1996 to 2002. Data analysis was conducted in 2010 and 2011.
  
  
  RESULTS
  Using a biopsy risk threshold of 2% and the standard risk factor model, 5% of women with a BI-RADS3 mammogram had a risk above the threshold, and 3% of women with BI-RADS4A mammograms had a risk below the threshold. The addition of 12 SNPs in the model resulted in 8% of women with a BI-RADS3 mammogram above the threshold for biopsy and 7% of women with BI-RADS4A mammograms below the threshold.
  
  
  CONCLUSIONS
  The incorporation of pre-test breast cancer risk factors could change biopsy decisions for a small proportion of women with abnormal mammograms. The greatest impact comes from standard breast cancer risk factors.
authors.affiliation: Department of Medicine, Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA 19104, USA. karmstro@mail.med.upenn.edu
authors.forename: Katrina
authors.initials: K
authors.lastname: Armstrong
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Handorf
authors.forename: Jinbo
authors.initials: J
authors.lastname: Chen
authors.forename: Mirar N
authors.initials: MN
authors.lastname: Bristol Demeter
mesh_terms: D001706:Biopsy; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D003657:Decision Making; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008403:Mass Screening / Q000379:methods*; D015233:Models, Statistical; D020641:Polymorphism, Single Nucleotide; D011237:Predictive Value of Tests; D012307:Risk Factors