Author(s):
do Nascimento, Catarina Neto ; 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
Date: 2023
Persistent ID: http://hdl.handle.net/10362/149274
Origin: Repositório Institucional da UNL
Subject(s): Epstein–Barr virus; females; gastric cancer; gender; microsatellite instability; molecular subtype; neoadjuvant chemotherapy; perioperative chemotherapy predictor; prognosis; Oncology; Cancer Research; SDG 3 - Good Health and Well-being
Description
Funding Information: This research was partially co-financed by Hospital da Luz Lisboa under the initiative “Luz Investigação” in the context of the Group GENIUS (Reference LH.INV.F2019015).
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.
