Ramos Marcus Fernando Kodama Pertille, Pereira Marina Alessandra, de Castria Tiago Biachi, Ribeiro Renan Ribeiro E, Cardili Leonardo, de Mello Evandro Sobroza, Zilberstein Bruno, Ribeiro-Júnior Ulysses, Cecconello Ivan
Instituto do Cancer, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Av Dr Arnaldo 251, Sao Paulo, SP, 01249000, Brazil.
J Cancer Res Clin Oncol. 2020 Dec;146(12):3373-3383. doi: 10.1007/s00432-020-03322-7. Epub 2020 Jul 15.
The importance of targeted therapy and interest in the study of predictive markers in gastric cancer (GC) have increased in recent years with the use of anti-HER2 therapy and immunotherapy with anti-PD1/PD-L1 for microsatellite instability (MSI) and PD-L1 + tumors. However, the behavior of remnant GC (RGC) in this scenario is poorly reported. Thus, this study aims to evaluate the clinicopathological characteristics and prognosis of RGC and its association with the expression of current markers for targeted therapy.
All RGC resections performed in a single center from 2009 to 2019 were retrospectively reviewed. As a comparison group, 53 primary proximal GC (PGC) who underwent total D2-gastrectomy were selected. HER2, MSI status and PD-L1 expression were analyzed by immunohistochemistry. Combined Positive Score (CPS) was used to determine PD-L1 positivity.
A total of 40 RGC were included. RGC patients were older (p = 0.001), had lower BMI (p = 0.001) and number of resected lymph nodes (p < 0.001) compared to the PGC. Regarding markers expression, MSI was higher in RGC than PGC (27.5% vs 9.4%, p = 0.022). The frequency of CPS-positive was 32.5% and 26.4% in RGC and PGC, respectively (p = 0.522). HER2 positivity was 17.5% and 22.6% for RGC and PGC, respectively (p = 0.543). In survival analysis, DFS was better for RGC CPS-positive than RGC CPS-negative (p = 0.039) patients. There was no difference in survival considering MSI status.
RGC had higher incidence of MSI than PGC, and CPS-positive RGC was associated with better survival. The immunological profile of RGC patients suggests that they would be good candidates for immunotherapy.
近年来，随着抗HER2治疗以及针对微卫星不稳定（MSI）和PD-L1阳性肿瘤的抗PD1/PD-L1免疫疗法的应用，胃癌（GC）靶向治疗的重要性以及对预测标志物研究的关注度均有所提高。然而，在这种情况下残余胃癌（RGC）的情况报道较少。因此，本研究旨在评估RGC的临床病理特征和预后及其与当前靶向治疗标志物表达的相关性。
回顾性分析2009年至2019年在单一中心进行的所有RGC切除术。作为对照组，选择53例行全胃D2切除术的原发性近端胃癌（PGC）患者。通过免疫组织化学分析HER2、MSI状态和PD-L1表达。采用联合阳性评分（CPS）来确定PD-L1阳性。
共纳入40例RGC患者。与PGC相比，RGC患者年龄更大（p = 0.001），体重指数更低（p = 0.001），切除淋巴结数量更少（p < 0.001）。关于标志物表达，RGC中MSI高于PGC（27.5%对9.4%，p = 0.022）。RGC和PGC中CPS阳性的频率分别为32.5%和26.4%（p = 0.522）。RGC和PGC的HER2阳性率分别为17.5%和22.6%（p = 0.543）。在生存分析中，RGC中CPS阳性患者的无病生存期（DFS）优于CPS阴性患者（p = 0.039）。考虑MSI状态时生存无差异。
RGC的MSI发生率高于PGC，且CPS阳性的RGC与更好的生存相关。RGC患者的免疫特征表明他们可能是免疫治疗的良好候选者。
