c-MET expression in primary and liver metastases in uveal melanoma

Melanoma Res. 2014 Dec;24(6):617-20. doi: 10.1097/CMR.0000000000000118.

Abstract

There is a pressing need for effective therapies to treat uveal melanoma. Agents that inhibit the c-MET pathway have shown promise in multiple malignancies that overexpress c-MET. Herein, we assess c-MET expression in both primary uveal melanoma and liver metastases of uveal melanoma and evaluate the association of c-MET expression with clinical and pathologic variables. We have retrospectively identified tumor samples from primary and liver metastases of uveal melanoma from 1 January 1990 to 1 January 2012. We utilized immunohistochemistry to assess c-MET expression, and two pathologists quantified c-MET expression using an H-score (product of the intensity of staining and percentage of positive cells). The Mann-Whitney U-test, Pearson's correlation, and Cox model were used as appropriate. Thirty-nine of 40 (98%) primary tumors and nine of 10 (90%) metastatic liver lesions expressed c-MET (H-score range 0-300). There was a strong association between the percentage of positive cells and the intensity of c-MET expression (P=0.007). We found no association between c-MET H-score and clinicopathologic variables such as age, sex, or stage. c-MET expression was significantly higher in metastatic compared with primary tumors (median H-score 190 vs. 30, P=0.022). c-MET is expressed in the vast majority of primary and liver metastases of uveal melanomas; however, c-MET expression did not associate with pathologic features in our cohort. Metastatic lesions have higher expression of c-MET expression than primary tumors. Clinical trials involving c-MET inhibitors deserve further study in patients with uveal melanoma in both the adjuvant and metastatic setting.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / metabolism*
  • Female
  • Humans
  • Immunohistochemistry
  • Liver / metabolism
  • Liver Neoplasms / secondary*
  • Male
  • Melanoma / pathology*
  • Middle Aged
  • Proto-Oncogene Proteins c-met / metabolism*
  • Retrospective Studies
  • Uveal Neoplasms / pathology*

Substances

  • Biomarkers, Tumor
  • Proto-Oncogene Proteins c-met

Supplementary concepts

  • Uveal melanoma