Conjunctival melanoma genomic analysis reveals intermediate tumor mutation burden and genomic overlap with cutaneous melanoma.

Conjunctival melanoma (CJM) is a rare and aggressive malignancy. Mainly attributed to its rarity, the genomic features of CJM have not been well characterized. In the present study, we sequenced the exomes of primary and metastatic CJM tumors with the aim to unravel their genomic landscape. The results of the study suggest that CJM is a molecularly distinct melanoma subtype with mixed genotype and targetable mutations. Notably, there were features overlapping with both mucosal, and mainly cutaneous melanoma. Of note, some genetic alterations were found in association with specific subsets of CJM, such as bulbar anatomical localization. CJM tumors had intermediate tumor mutational burden, which was significantly higher compared to most cancers included in the cancer genome atlas (TCGA) project and suggest a role for immune checkpoint inhibitor treatment in patients with locally advanced or metastatic disease. These data allow for a better evaluation of the therapeutic options for CJM.