Overexpression of Epidermal Growth Factor Receptor Restricted to Macrophages in Uveal Melanoma

Arch Ophthalmol. 2001 Mar;119(3):373-7. doi: 10.1001/archopht.119.3.373.

Abstract

Objective: To determine whether expression of the epidermal growth factor receptor (EGFR) is of prognostic value in uveal melanoma.

Methods: Thirty consecutive patients treated for primary posterior uveal melanoma by enucleation or local resection were studied. Tumors were examined for EGFR and CD68 expression by immunohistochemistry on formalin-fixed, paraffin-embedded sections. Extracted DNA from paired frozen tumor and blood samples was examined for loss of heterozygosity on chromosome 3 using polymerase chain reaction-based microsatellite analysis. Immunoreactivity for EGFR was correlated with clinicopathological, chromosome 3, and follow-up data.

Results: Immunoreactivity for EGFR was observed in 7 (23%) of 30 uveal melanomas, but was restricted to solitary or small groups of cells with macrophage-like morphology. Immunoreactive cells were confirmed as macrophages using an antibody to the macrophage marker CD68. Chromosome 3 loss, epithelioid cells, and microvascular loops were detected in 17 (57%), 22 (73%) and 19 (63%) of the 30 tumors, respectively. Metastatic disease was detected in 5 patients (17%). No correlation was found between any of these variables and EGFR positivity.

Conclusions: The absence of EGFR immunoreactivity in tumor cells does not support the use of EGFR expression as a prognostic indicator in patients with uveal melanoma. Future EGFR studies in uveal melanoma should be interpreted with caution in view of our findings that tumor-associated macrophages can express this receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD / metabolism
  • Antigens, Differentiation, Myelomonocytic / metabolism
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism*
  • DNA, Neoplasm / metabolism
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism*
  • Eye Enucleation
  • Humans
  • Immunoenzyme Techniques
  • Macrophages / enzymology*
  • Macrophages / pathology
  • Melanoma / enzymology*
  • Melanoma / genetics
  • Melanoma / surgery
  • Polymerase Chain Reaction
  • Prognosis
  • Uveal Neoplasms / enzymology*
  • Uveal Neoplasms / genetics
  • Uveal Neoplasms / surgery

Substances

  • Antigens, CD
  • Antigens, Differentiation, Myelomonocytic
  • Biomarkers, Tumor
  • CD68 antigen, human
  • DNA, Neoplasm
  • ErbB Receptors