KIT, PDGFRalpha and EGFR analysis in nephroblastoma

Virchows Arch. 2008 Jun;452(6):637-50. doi: 10.1007/s00428-008-0605-x. Epub 2008 May 14.

Abstract

Nephroblastoma prognosis has dramatically improved, but an unfavourable prognostic subgroup warrants development of novel therapeutic strategies. Selective KIT, PDGFRalpha and epidermal growth factor receptor (EGFR) tyrosine kinase inhibition evolved as powerful targeted therapy for gastrointestinal stromal tumours and non-small-cell lung cancer. To investigate a potential role for tyrosine kinase inhibition, we analyzed 209 nephroblastomas for immunohistochemical KIT and EGFR expression, 63 nephroblastomas for mutations in KIT exons 9, 11, 13, EGFR exons 18, 19, 20 and 21, and all 209 nephroblastomas for PDGFRalpha exons 12, 14 and 18. Twenty-two tumours (10.5%) expressed KIT, 31 (14.8%) EGFR, and 10 (4.8%) both KIT and EGFR, respectively. KIT expression was relatively more common among high-risk tumours (6/27; 22.3%) compared to low-/intermediate-risk tumours (26/181; 14.4%). Nine patients deceased, four of which had high-risk tumours with KIT expression in two of four and EGFR expression in one of four. There were no KIT, PDGFRalpha or EGFR mutations. Our results suggest no significant contribution of KIT, EGFR or PDGFRalpha mutations to nephroblastoma pathogenesis. Despite a trend towards association of immunohistochemical KIT and EGFR expression with poor outcome in high-risk nephroblastomas, statistical analysis did not yield significant correlations in this subgroup. Therefore, it remains open if KIT, PDGFRalpha or EGFR tyrosine kinase inhibition constitute a therapeutic target in nephroblastoma in the absence of KIT, PDGFRalpha or EGFR mutations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Child, Preschool
  • ErbB Receptors / biosynthesis*
  • Female
  • Humans
  • Immunohistochemistry
  • Male
  • Molecular Sequence Data
  • Proto-Oncogene Proteins c-kit / biosynthesis*
  • Proto-Oncogene Proteins c-kit / genetics
  • Receptor, Platelet-Derived Growth Factor alpha / antagonists & inhibitors
  • Receptor, Platelet-Derived Growth Factor alpha / biosynthesis*
  • Receptor, Platelet-Derived Growth Factor alpha / genetics
  • Wilms Tumor / drug therapy
  • Wilms Tumor / metabolism*

Substances

  • ErbB Receptors
  • Proto-Oncogene Proteins c-kit
  • Receptor, Platelet-Derived Growth Factor alpha