title: Background parenchymal enhancement on breast MRI: association with recurrence-free survival in patients with newly diagnosed invasive breast cancer.
abstract: OBJECTIVE
  To determine whether BPE in preoperative breast MRI influences patients' recurrence-free survival (RFS).
  
  
  METHODS
  Between February 2010 and December 2011, 804 consecutive women with invasive breast cancer who had undergone preoperative breast MRI and curative cancer surgery were identified. BPE was visually graded by two reviewers. We determined the correlation between BPE grade and other clinicopathological variables, including age, adjuvant therapy, menopausal status, histologic grade, T stage, N stage, lymphovascular invasion, molecular subtype, surgical margin status, and mammographic density. A Cox proportional hazards model was used to analyze the effects of clinicopathological variables and radiological findings (BPE grade, mammographic density) on RFS.
  
  
  RESULTS
  High BPE was associated with premenopausal status (Ps < 0.0001), higher mammographic density (Ps < 0.0001), progesterone receptor positivity (Ps = 0.039, 0.007, respectively), presence of lymphovascular invasion (Ps = 0.008, 0.001, respectively), and close surgical margin (Ps < 0.0001). Recurrences were observed in 75 patients after a mean follow-up period of 61.8 months (range 4-81 months). Non-minimal BPE grade (RFS hazard ratio = 3.086, P = 0.003 for reader 1; RFS hazard ratio = 2.221, P = 0.075 for reader 2) and T3 stage were associated with worse outcomes in postmenopausal women. In premenopausal women, non-minimal BPE grade by readers 1 and 2 did not affect the patients' outcomes.
  
  
  CONCLUSIONS
  Increased BPE on preoperative breast MRI in postmenopausal women has potential as a predictor of poor RFS.
authors.affiliation: Department of Statistics, Pukyong National University, 45 Yongso-ro, Nam-Gu, Busan, 48513, Korea.
authors.forename: Yaeji
authors.initials: Y
authors.lastname: Lim
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Korea. mathilda0330@gmail.com.
authors.forename: Eun Sook
authors.initials: ES
authors.lastname: Ko
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Korea.
authors.forename: Boo-Kyung
authors.initials: BK
authors.lastname: Han
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Ko
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Korea.
authors.forename: Ji Soo
authors.initials: JS
authors.lastname: Choi
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Korea.
authors.forename: Jeong Eon
authors.initials: JE
authors.lastname: Lee
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Korea.
authors.forename: Se Kyung
authors.initials: SK
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000000981:diagnostic imaging* / Q000473:pathology; D000071060:Breast Density; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media / Q000627:therapeutic use; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000473:pathology; D016016:Proportional Hazards Models
chemical_list: D003287:Contrast Media
keywords: Background parenchymal enhancement; Breast cancer; Magnetic resonance imaging; Menopausal status; Prognosis