title: Quantum dot-based quantitative immunofluorescence detection and spectrum analysis of epidermal growth factor receptor in breast cancer tissue arrays.
abstract: BACKGROUND
  The epidermal growth factor receptor (EGFR) is a promising therapeutic target in cancer, but its clinical value in breast cancer remains controversial. Our previous studies have found that quantitative analysis of biomarkers with quantum dot-based nanotechnology had better detection performance than conventional immunohistochemistry. The present study was undertaken to investigate the prognostic value of EGFR in breast cancer using quantum dot-based quantitative spectral analysis.
  
  
  METHODS
  EGFR expression in 65 breast cancer specimens was detected by immunohistochemistry and quantum dot-immunohistochemistry, and comparisons were made between the two methods. EGFR expression in tissue microarrays of 240 breast cancer patients was then detected by quantum dot-immunohistochemistry and spectral analysis. The prognostic value of EGFR immunofluorescence area (EGFR area) for five-year recurrence-free survival was investigated.
  
  
  RESULTS
  The same antigen localization, high correlation of staining rates (r = 0.914), and high agreement of measurement (κ = 0.848) of EGFR expression in breast cancer were found by quantum dot-immunohistochemistry and immunohistochemistry. The EGFR area showed significant differences by tumor grade, lymph node status, HER2 status, and hormone receptor status (all P < 0.05). Patients in the large EGFR area (≥ 30.51) group had a significantly higher five-year recurrence rate (47.2% versus 27.4%, P = 0.002) and worse five-year recurrence-free survival (log-rank test, P = 0.0015) than those in the small EGFR area (<30.51) group. In the subgroups, EGFR area was an independent prognosticator in the HER2-positive and lymph node-positive subgroups.
  
  
  CONCLUSIONS
  Quantum dot-based quantitative detection demonstrates the prognostic value of EGFR area in the HER2-positive and lymph node-positive subgroups of invasive breast cancer.
authors.affiliation: Department of Oncology, Zhongnan Hospital of Wuhan University, Hubei Key Laboratory on Tumor Biological Behaviors and Hubei Cancer Clinical Study Center, Wuhan, People's Republic of China.
authors.forename: Xue-Qin
authors.initials: XQ
authors.lastname: Yang
authors.forename: Chuang
authors.initials: C
authors.lastname: Chen
authors.forename: Chun-Wei
authors.initials: CW
authors.lastname: Peng
authors.forename: Jin-Xuan
authors.initials: JX
authors.lastname: Hou
authors.forename: Shao-Ping
authors.initials: SP
authors.lastname: Liu
authors.forename: Chu-Bo
authors.initials: CB
authors.lastname: Qi
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Gong
authors.forename: Xiao-Bo
authors.initials: XB
authors.lastname: Zhu
authors.forename: Dai-Wen
authors.initials: DW
authors.lastname: Pang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000032:analysis* / Q000378:metabolism; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008856:Microscopy, Fluorescence / Q000379:methods*; D008875:Middle Aged; D016016:Proportional Hazards Models; D045663:Quantum Dots; D012372:ROC Curve; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D046888:Tissue Array Analysis / Q000379:methods*
chemical_list: D066246:ErbB Receptors; D018719:Erb-b2 Receptor Tyrosine Kinases
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