title: Prediction of near-term breast cancer risk based on bilateral mammographic feature asymmetry.
abstract: OBJECTIVE
  The objective of this study is to investigate the feasibility of predicting near-term risk of breast cancer development in women after a negative mammography screening examination. It is based on a statistical learning model that combines computerized image features related to bilateral mammographic tissue asymmetry and other clinical factors.
  
  
  METHODS
  A database of negative digital mammograms acquired from 994 women was retrospectively collected. In the next sequential screening examination (12 to 36 months later), 283 women were diagnosed positive for cancer, 349 were recalled for additional diagnostic workups and later proved to be benign, and 362 remain negative (not recalled). From an initial pool of 183 features, we applied a Sequential Forward Floating Selection feature selection method to search for effective features. Using 10 selected features, we developed and trained a support vector machine classification model to compute a cancer risk or probability score for each case. The area under the receiver operating characteristic curve and odds ratios (ORs) were used as the two performance assessment indices.
  
  
  RESULTS
  The area under the receiver operating characteristic curve = 0.725 ± 0.018 was obtained for positive and negative/benign case classification. The ORs showed an increasing risk trend with increasing model-generated risk scores (from 1.00 to 12.34, between positive and negative/benign case groups). Regression analysis of ORs also indicated a significant increase trend in slope (P = .006).
  
  
  CONCLUSIONS
  This study demonstrates that the risk scores computed by a new support vector machine model involving bilateral mammographic feature asymmetry have potential to assist the prediction of near-term risk of women for developing breast cancer.
authors.affiliation: School of Electrical and Computer Engineering, University of Oklahoma, 101 David L. Boren Blvd, Norman, OK 73019. Electronic address: maxinetyl@gmail.com.
authors.forename: Maxine
authors.initials: M
authors.lastname: Tan
authors.forename: Bin
authors.initials: B
authors.lastname: Zheng
authors.forename: Pandiyarajan
authors.initials: P
authors.lastname: Ramalingam
authors.forename: David
authors.initials: D
authors.lastname: Gur
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008327:Mammography / Q000379:methods* / Q000706:statistics & numerical data; D016017:Odds Ratio; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D018570:Risk Assessment; D060388:Support Vector Machine
keywords: Bilateral mammographic feature asymmetry; breast cancer; cancer risk prediction model; computer-aided detection (CAD) of mammograms