Purpose: In order to obtain better insight into the genetic background of nodular melanoma (NM), we aimed to analyse the frequency of CDKN2A and C-MYC copy number changes. The impact of these aberrations on the metastatic potential and patient's survival was considered.
Methods: Fluorescent in situ hybridization was used to analyse the C-MYC and CDKN2A genes on isolated nuclei from 49 paraffin-embedded primary NMs.
Results: Thirty-six (73.47%) melanoma samples showed CDKN2A deletion while 11 of these 36 (22.45%) additionally displayed C-MYC increased copy numbers. Cases positive for metastases more commonly displayed CDKN2A deletions. However, the combined C-MYC and CDKN2A aberrations were found predominantly in the non-metastasizing group of primary NM. The survival analysis furthermore demonstrated that patients with combined CDKN2A and C-MYC aberrations have a significantly better prognosis than carriers of CDKN2A deletion only.
Conclusions: We conclude that the C-MYC increased copy number changes on the background of CDKN2A deletions seem to be related to a low metastatic potential and better patients' outcome in primary NMs.