EBV and MSI status in gastric cancer: does it matter?

• Autor(a) principal: Nascimento, Catarina Neto do
• Data de Publicação: 2023
• Outros Autores: Mascarenhas-Lemos, Luís, Silva, João Ricardo, Marques, Diogo Sousa, Gouveia, Catarina Ferreira, Faria, Ana, Velho, Sónia, Garrido, Rita, Maio, Rui, Costa, Andreia, Pontes, Patrícia, Wen, Xiaogang, Gullo, Irene, Cravo, Marília, Carneiro, Fátima
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.14/40063
• topic: Epstein–Barr virus; Females; Gastric cancer; Gender; Microsatellite instability; Molecular subtype; Neoadjuvant chemotherapy; Perioperative chemotherapy predictor; Prognosis

We investigated the impactof microsatellite instability (MSI) and Epstein–Barr virus (EBV) status in gastric cancer (GC), regarding response to perioperative chemotherapy (POPChT), overall survival (OS), and progression-free survival (PFS). We included 137 cases of operated GC, 51 of which were submitted to POPChT. MSI status was determined by multiplex PCR and EBV status by EBV-encoded RNA in situ hybridization. Thirty-seven (27%) cases presented as MSI-high, and seven (5.1%) were EBV+. Concerning tumor regression after POPChT, no differences were observed between the molecular subtypes, but females were more likely to respond (p = 0.062). No significant differences were found in OS or PFS between different subtypes. In multivariate analysis, age (HR 1.02, IC 95% 1.002–1.056, p = 0.033) and positive lymph nodes (HR 1.82, IC 95% 1.034–3.211, p = 0.038) were the only prognostic factors for OS. However, females with MSI-high tumors treated with POPChT demonstrated a significantly increased OS compared to females with MSS tumors (p = 0.031). In conclusion, we found a high proportion of MSI-high cases. MSI and EBV status did not influence OS or PFS either in patients submitted to POPChT or surgery alone. However, superior survival of females with MSI-high tumors suggests that sex disparities and molecular classification may influence treatment options in GC.