Immunohistochemical expression and prognostic significance of MAGE-A in canine oral malignant melanoma

Guillén, Alexandra; Stiborova, Katerina; Ressel, Lorenzo; Blackwood, Laura; Finotello, Riccardo; Amores-Fuster, Isabel; Jama, Nimo; Killick, David

Abstract

Canine oral malignant melanoma (COMM) is considered a chemo-resistant cancer with a poor long-term prognosis. The melanoma-associated antigen A (MAGE-A) genes, which belong to the cancer-testis antigen family, are expressed in several different canine cancers but not in normal somatic tissue. This study evaluates the expression of MAGE-A proteins and their prognostic role in COMM. The study was conducted in 2 parts. During the first part, biopsies from oral malignant melanomas from 43 dogs were examined and immunohistochemically assessed for expression of MAGE-A proteins. For the second part, the association between MAGE-A expression and outcome was assessed using follow-up data which was available for 20 dogs whose primary tumour had been controlled with surgery +/ radiation therapy. MAGE-A proteins were expressed in 88.4% (38/43) of oral malignant melanomas and had a predominantly cytoplasmic expression pattern. Immunopositivity was observed in more than 50% of the cells in 21 dogs (48.8%). Immunostaining intensity was classified as weak, moderate and intense in 16 (37%), 16 (37%) and 6 (14%) cases, respectively. No staining for MAGE-A was seen in 5 dogs (11%). Dogs whose COMM had weak MAGE-A staining intensity had a median survival time (MST) of 320 days while this was 129 days for dogs with moderate and intense immunostaining (p = 0.161). Dogs whose COMM had >50% of positive staining neoplastic cells had an MST of 141 days and dogs with a staining <50% had an MST of 320 days (p = 0.164). MAGE-A expression did not influence survival in our cohort.

Citation

Guillén, A., Stiborova, K., Ressel, L., Blackwood, L., Finotello, R., Amores-Fuster, I., Jama, N., & Killick, D. (2021). Immunohistochemical expression and prognostic significance of MAGE-A in canine oral malignant melanoma. Research in Veterinary Science, 137, 226-234. https://doi.org/10.1016/j.rvsc.2021.05.009

• Journal Article Type: Article
• Acceptance Date: May 12, 2021
• Online Publication Date: May 15, 2021
• Publication Date: 2021-07
• Deposit Date: May 15, 2024
• Journal: Research in Veterinary Science
• Print ISSN: 0034-5288
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 137
• Pages: 226-234
• DOI: https://doi.org/10.1016/j.rvsc.2021.05.009
• Keywords: General Veterinary
• Additional Information: This article is maintained by: Elsevier; Article Title: Immunohistochemical expression and prognostic significance of MAGE-A in canine oral malignant melanoma; Journal Title: Research in Veterinary Science; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.rvsc.2021.05.009; Content Type: article; Copyright: Crown Copyright © 2021 Published by Elsevier Ltd. All rights reserved.