title: MRI enhancement in stromal tissue surrounding breast tumors: association with recurrence free survival following neoadjuvant chemotherapy.
abstract: OBJECTIVE
  Normal-appearing stromal tissues surrounding breast tumors can harbor abnormalities that lead to increased risk of local recurrence. The objective of this study was to develop a new imaging methodology to characterize the signal patterns of stromal tissue and to investigate their association with recurrence-free survival following neoadjuvant chemotherapy.
  
  
  METHODS
  Fifty patients with locally-advanced breast cancer were imaged with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) before (V1) and after one cycle (V2) of adriamycin-cytoxan therapy. Contrast enhancement in normal-appearing stroma around the tumor was characterized by the mean percent enhancement (PE) and mean signal enhancement ratio (SER) in distance bands of 5 mm from the tumor edge. Global PE and SER were calculated by averaging all stromal bands 5 to 40 mm from tumor. Proximity-dependent PE and SER were analyzed using a linear mixed effects model and Cox proportional hazards model for recurrence-free survival.
  
  
  RESULTS
  The mixed effects model displayed a decreasing radial trend in PE at both V1 and V2. An increasing trend was less pronounced in SER. Survival analysis showed that the hazard ratio estimates for each unit decrease in global SER was statistically significant at V1 [estimated hazard ratio = 0.058, 95% Wald CI (0.003, 1.01), likelihood ratio p = 0.03]; but was not so for V2.
  
  
  CONCLUSIONS
  These findings show that stromal tissue outside the tumor can be quantitatively characterized by DCE-MRI, and suggest that stromal enhancement measurements may be further developed for use as a potential predictor of recurrence/disease-free survival following therapy.
authors.affiliation: Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, United States of America. ella.jones@ucsf.edu
authors.forename: Ella F
authors.initials: EF
authors.lastname: Jones
authors.forename: Sumedha P
authors.initials: SP
authors.lastname: Sinha
authors.forename: David C
authors.initials: DC
authors.lastname: Newitt
authors.forename: Catherine
authors.initials: C
authors.lastname: Klifa
authors.forename: John
authors.initials: J
authors.lastname: Kornak
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Park
authors.forename: Nola M
authors.initials: NM
authors.lastname: Hylton
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio