Abstract 2222: The molecular landscape of acral lentiginous melanoma in Mexican patients

Abstract

Abstract Acral lentiginous melanoma (ALM) is the most common melanoma subtype in several countries in Africa, Asia, and Latin America, including Mexico. Comparatively fewer studies have been published of ALM than other subtypes of the disease. However, it is becoming clear that complex DNA structural aberrations, as well as several genes, such as NOTCH2, KIT, PTEN and TYRP1, in addition to the established melanoma drivers, play a role in its development. To date, no comprehensive genomic characterization has been performed on tumors from Latin American patients. The causes of ALM are unknown, and little is known about its transcriptomic profile and immune landscape. Because of these factors, therapeutic options are limited, while approaches such as immunotherapy are too costly for most patients in Latin American countries, and are of unknown efficacy in rarer forms of melanoma such as ALM. A better understanding of the molecular and immune profile of ALM would allow us to identify potential therapeutic targets and treatment strategies in this population. We have sequenced the exomes and transcriptomes of 113 ALM tumors (primaries, metastases and recurrences) from 86 patients being treated at the National Cancer Institute of Mexico, a national reference hospital. We have performed analyses to define the genomic landscape of the disease, its mutational signatures, the biological pathways involved in its development, and its immune profile. From these analyses, we have identified recurrently amplified and deleted genomic regions, potential causal agents, and the involvement of specific interleukins and cell-adhesion proteins in ulcerated and metastatic tumors. This study is one of the first to profile the molecular landscape of ALM in a Latin American population. We hope that it will contribute to increasing the diversity of cancer genomics datasets, help highlight differences in disease biology, and provide insights that may inform therapeutic strategies for all patients with this lethal malignancy. Citation Format: Martha E. Vázquez-Cruz, Patricia Basurto-Lozada, Christian Molina-Aguilar, Carolina Castaneda-Garcia, Ingrid Ferreira, Héctor Martínez-Said, Alethia Álvarez-Cano, Luis Alberto Tavares-de la Paz, Diego Hinojosa-Ugarte, Dorian Y. García-Ortega, Julia M. Martínez-Gómez, Mitchell P. Levesque, David J. Adams, Carla D. Robles-Espinoza. The molecular landscape of acral lentiginous melanoma in Mexican patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2222.