title: Characterization of metabolic differences between benign and malignant tumors: high-spectral-resolution diffuse optical spectroscopy.
abstract: OBJECTIVE
  To develop a near-infrared spectroscopic method to identify breast cancer biomarkers and to retrospectively determine if benign and malignant breast lesions could be distinguished by using this method.
  
  
  METHODS
  The study was HIPAA compliant and was approved by the university institutional review board. Written informed consent was obtained. By using self-referencing differential spectroscopy (SRDS) analysis, the existence of specific spectroscopic signatures of breast lesions on images acquired by using diffuse optical spectroscopy imaging in the wavelength range (650-1000 nm) was established. The SRDS method was tested in 60 subjects (mean age, 38 years; age range, 22-74 years). There were 17 patients with benign breast tumors and 22 patients with malignant breast tumors. There were 21 control subjects.
  
  
  RESULTS
  Discrimination analysis helped separate malignant from benign tumors. A total of 40 lesions (22 malignant and 18 benign) were analyzed. Twenty were true-positive lesions, 17 were true-negative lesions, one was a false-positive lesion, and two were false-negative lesions (sensitivity, 91% [20 of 22]; specificity, 94% [17 of 18]; positive predictive value, 95% [20 of 21]; and negative predictive value, 89% [17 of 19]).
  
  
  CONCLUSIONS
  The SRDS method revealed localized tumor biomarkers specific to pathologic state.
authors.affiliation: Beckman Laser Institute, University of California, Irvine, CA 92612, USA.
authors.forename: Shwayta
authors.initials: S
authors.lastname: Kukreti
authors.forename: Albert E
authors.initials: AE
authors.lastname: Cerussi
authors.forename: Wendy
authors.initials: W
authors.lastname: Tanamai
authors.forename: David
authors.initials: D
authors.lastname: Hsiang
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Tromberg
authors.forename: Enrico
authors.initials: E
authors.lastname: Gratton
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D016022:Case-Control Studies; D016002:Discriminant Analysis; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation*; D018709:Statistics, Nonparametric
chemical_list: D014408:Biomarkers, Tumor