Conjunctival melanoma copy number alterations and correlation with mutation status, tumor features and clinical outcome

Relatively little is known about the genetic aberrations of conjunctival melanomas (CoM) and their correlation with clinical and histomorphological features as well as prognosis. The aim of this large collaborative multicentre study was to determine potential key biomarkers for metastatic risk and any druggable targets for high-risk metastatic CoM. Using Affymetrix Single Nucleotide Polymorphism genotyping arrays on 59 CoM, we detected frequent amplifications on chromosome (chr) 6p and deletions on 7q, and characterised mutation-specific copy number alterations. Deletions on chr 10q11.21-26.2, a region harbouring the tumor suppressor genes, PDCD4, SUFU, NEURL1, PTEN, RASSF4, DMBT1 and C10orf90 & 99 significantly correlated with metastases (Fisher’s Exact, p≤0.04), lymphatic invasion (Fisher’s Exact, p≤0.02), increasing tumor thickness (Mann-Whitney, p≤0.02) and BRAF mutation (Fisher’s Exact, p≤0.05). This enhanced insight into CoM biology is a step towards identifying patients at risk of metastasis and potential therapeutic targets for systemic disease. 59 samples in total: 52 primary and 7 locally recurrent conjuncitval melanoma (CoM)