Effects of plaque brachytherapy and proton beam radiotherapy on prognostic testing: a comparison of uveal melanoma genotyped by microsatellite analysis. Issue 10 (5th February 2020)

• Record Type: Journal Article
• Authors: Thornton, Sophie; Coupland, Sarah E; Heimann, Heinrich; Hussain, Rumana; Groenewald, Carl; Kacperek, Andrzej; Damato, Bertil; Taktak, Azzam; Eleuteri, Antonio; Kalirai, Helen
• Is Part Of: British journal of ophthalmology. Volume 104:Issue 10(2020)
• Page Start: 1462
• Page End: 1466
• Publication Date: 2020-02-05
• Subjects: genetics -- neoplasia -- iris -- eye (globe) -- diagnostic tests/investigation; Ophthalmology -- Periodicals; 617.7
• DOI: 10.1136/bjophthalmol-2019-315363
• Languages: English
• ISSNs: 0007-1161

Abstract

Abstract : Background/aims: Proton beam radiotherapy and plaque brachytherapy are commonly applied in primary uveal melanoma (UM); however, their effect on chromosome 3 classification of UM by microsatellite analysis (MSA) for prognostication purposes is unknown, where the tumour is sampled post-irradiation. This study examined the prognostic accuracy of genotyping UM biopsied before or after administration of radiotherapy, by MSA. Methods: 407 UM patients treated at the Liverpool Ocular Oncology Centre between January 2011 to December 2017, were genotyped for chromosome 3 by MSA; 172 and 176 primary UM were sampled prior to and post irradiation, respectively. Results: Genotyping by MSA was successful in 396/407 (97%) of UM samples (196 males, 211 females; median age of 61 years (range 12 to 93) at primary treatment). There was no demonstrable association between a failure of MSA to produce a chromosome 3 classification and whether radiation was performed pre-biopsy or post-biopsy with an OR of 0.96 (95% CI 0.30 to 3.00, p=0.94). There was no evidence of association (measured as HRs) between risk of metastatic death and sampling of a primary UM before administration of radiotherapy (HR 1.1 (0.49 to 2.50), p=0.81). Monosomy 3 (HR 12.0 (4.1 to 35.0), p<0.001) was significantly associated with increased risk of metastatic death. Conclusions and relevance: This study revealed that successful genotyping of UM using MSA is possible, irrespective of irradiation status. Moreover, we found no evidence that biopsy prior to radiotherapy increases metastatic mortality.