title: Is lymphatic endoglin expression a risk marker for breast cancer metastasis? Results of a pilot study.
abstract: BACKGROUND
  Studies have identified endoglin as a biological marker that is overexpressed on the microvessels of certain solid cancers (breast, colorectal cancer, and head and neck squamous cell cancers). There is, at present, no immunohistochemical marker that can discriminate between lymph node-negative and or lymph node-positive breast cancer tissue.
  
  
  METHODS
  The expression of endoglin was quantified by immunohistochemistry and assessment of microvessel density in 53 surgical specimens. These were comprised of breast tumor tissue that had not spread to the regional lymph nodes (lymph node-negative breast tumor tissue: 20 specimens), breast tumor tissue had spread to regional lymph nodes (lymph node-positive breast tumor tissue: 21 specimens), and normal breast tissue as a control (12 specimens).
  
  
  RESULTS
  Significant difference was observed between the expression of endoglin on microvessels of lymph node-negative and lymph node-positive breast cancer tissue (p<0.05). This significant difference was shown to be due to endoglin expression on lymphatic vessels (p<0.02), rather than on blood vessels (p>0.05).
  
  
  CONCLUSIONS
  These findings are the first to suggest that endoglin expression on breast tumor lymphatic vessels may have diagnostic potential as a discriminator between lymph node-negative and lymph node-positive breast cancer. Further studies would be required to confirm this.
authors.affiliation: Research and Development Department, Dumfries and Galloway Royal Infirmary, Dumfries, Scotland, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Clasper
authors.forename: S O
authors.initials: SO
authors.lastname: Ogunbiyi
authors.forename: G
authors.initials: G
authors.lastname: Baxter
authors.forename: L
authors.initials: L
authors.lastname: Turnbull
authors.forename: S
authors.initials: S
authors.lastname: Holt
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D001808:Blood Vessels / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D003937:Diagnosis, Differential; D000071063:Endoglin; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D042601:Lymphatic Vessels / Q000378:metabolism*; D010865:Pilot Projects; D011956:Receptors, Cell Surface / Q000096:biosynthesis*; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor; C064206:ENG protein, human; D000071063:Endoglin; D011956:Receptors, Cell Surface