Comparative Cytogenetic Abnormalities in Paired Choroidal Melanoma Samples Obtained Before and After Proton Beam Irradiation by Transscleral Fine-Needle Aspiration Biopsy and Endoresection

• Published in: Cancers Vol. 11; no. 8; p. 1173
• Main Authors: Matet, Alexandre, Aït Raïs, Khadija, Malaise, Denis, Angi, Martina, Dendale, Rémi, Tick, Sarah, Lumbroso-Le Rouic, Livia, Lévy-Gabriel, Christine, Rodrigues, Manuel, Pierron, Gaëlle, Cassoux, Nathalie
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 14.08.2019; MDPI
• Subjects: Biopsy; choroidal melanoma; chromosome; Chromosome 3; Chromosomes; Cytogenetics; endoresection; fine-needle aspiration biopsy; genomic; Hybridization; irradiation; Melanoma; Metastasis; Monosomy; Next-generation sequencing; proton beam therapy; Radiation; Radiation therapy; Tantalum; Tumors; uveal melanoma; genomic; uveal melanoma; chromosome; fine-needle aspiration biopsy; endoresection; proton beam therapy; irradiation; choroidal melanoma
• ISSN: 2072-6694; 2072-6694
• DOI: 10.3390/cancers11081173

This study compared the cytogenetic profiles of choroidal melanoma samples retrieved before and after proton beam irradiation. Twenty-four consecutive patients who underwent both fine-needle aspiration biopsy (FNAB) during tantalum clip positioning, and endoresection within three months of irradiation, were retrospectively included. Chromosome alterations were explored by array comparative genomic hybridization. Age at diagnosis was 50 ± 14 years, tumor thickness was 8.6 ± 1.7 mm and tumor diameter was 12.4 ± 2.3 mm. Six FNAB samples were non-contributive (25%), versus one endoresection sample (4%) ( = 0.049). Among 17 cases with paired contributive samples, the profiles of chromosomes 3 and 8 were identical in all cases, except one with partial chromosome 3 loss on the FNAB sample only. Three cases presented additional discordant aberrations on chromosomes other than 3 or 8q. Overall, we identified monosomy 3 in two cases, 8q gain in six cases, and both alterations in three cases. All cases presented or mutations assessed by a custom next-generation sequencing panel. Among the six cases with non-contributive initial FNAB, three cases presented abnormal 3 or 8q chromosomes detected on the endoresection material. These results demonstrate the higher rentability of endoresection material for cytogenetic analysis compared to FNAB, and provide clinical evidence of tumor heterogeneity in choroidal melanoma.