Identificación del Virus Epstein-Barr por Hibridación in situ en pacientes con Cáncer Gástrico que asisten al Instituto de Cancerología (Incan) de Guatemala

El Virus Epstein Barr (EBV) está relacionado como agente oncogénico en el desarrollo del cáncer gástrico, atribuyéndosele el 10 % de los casos de esta neoplasia a nivel mundial. No existen estudios previos que identifiquen la presencia EBV en los pacientes con cáncer gástrico en Guatemala, por lo que en este estudio se evaluó por hibridación in situ la presencia del micro ARN EBER (Epstein Barr-encoded RNAs) de EBV en 71 pacientes con cáncer gástrico que asistieron al Instituto de Cancerología (Incan). Se determinó una prevalencia de 21.1 % (IC 95 % [10.9, 31.3] ) (15 pacientes), mayor que la reportada en otros estudios latinoamericanos. Se determinó asociación significativa entre la expresión del EBER del EBV, y el género masculino OR = 4.9 (IC 95% [1.4, 17.5]) p < .05. Los factores asociados fueron, el padecer diarrea OR 5.7 IC 95 % [1.5, 12.6] p = .008, y la detección del anticuerpos de Helicobacter pylori séricos, OR 7.2 (IC 95 % [1.1, 18.9]) p = .03. Aun cuando la mayoría de los pacientes que expresan el EBER de EBV desarrollaron cáncer gástrico del tipo difuso 66.67 % noexiste asociación significativa p = 0.13 OR = 2.5 (IC 95 % [1.1, 8.2])

Geographic EBV variants confound disease-specific variant interpretation and predict variable immune therapy responses

Epstein-Barr virus (EBV) is a potent carcinogen linked to hematologic and solid malignancies and causes significant global morbidity and mortality. Therapy using allogeneic EBV-specific lymphocytes shows promise in certain populations, but the impact of EBV genome variation on these strategies remains unexplored. To address this, we sequenced 217 EBV genomes, including hematologic malignancies from Guatemala, Peru, Malawi, and Taiwan, and analyzed them alongside 1307 publicly available EBV genomes from cancer, nonmalignant diseases, and healthy individuals across Africa, Asia, Europe, North America, and South America. These included, to our knowledge, the first natural killer (NK)/T-cell lymphoma (NKTCL) EBV genomes reported outside of East Asia. Our findings indicate that previously proposed EBV genome variants specific to certain cancer types are more closely tied to geographic origin than to cancer histology. This included variants previously reported to be specific to NKTCL but were prevalent in EBV genomes from other cancer types and healthy individuals in East Asia. After controlling for geographic region, we did identify multiple NKTCL-specific variants associated with a 7.8-fold to 21.9-fold increased risk. We also observed frequent variations in EBV genomes that affected peptide sequences previously reported to bind common major histocompatibility complex alleles. Finally, we found several nonsynonymous variants spanning the coding sequences of current vaccine targets BALF4, BKRF2, BLLF1, BXLF2, BZLF1, and BZLF2. These results highlight the need to consider geographic variation in EBV genomes when devising strategies for exploiting adaptive immune responses against EBV-related cancers, ensuring greater global effectiveness and equity in prevention and treatment