Abstract：
BACKGROUND: Gastric epithelial tumors exhibit morphological heterogeneity, diverse biological behaviors, and different oncopathological pathways. The Cancer Genome Atlas (TCGA) proposed a molecular classification of gastric adenocarcinomas based on genetic and molecular findings, which shows particular characteristics of diagnosis, prognosis, and indirectly, therapeutic alternatives. Within this classification, Epstein-Barr virus-positive (EBV+) and high microsatellite instability (MSI-H) subtypes stand out as subtypes that present a less aggressive biological behavior and a highly mutilated phenotype. This study conducted a systematic review with an emphasis on epidemiological and prognostic factors based on the molecular classification proposed by TCGA.
METHODS: A broad, comprehensive, and reproducible search with methodological rigor was conducted for study selection using the ROBINS-I and GRADEpro protocols and appropriate combinations of keywords.
RESULTS: A total of 25 studies were selected: six with a complete classification similar to TCGA and 19 with a distinction between MSI-H and EBV+. The application of meta-analysis calculations reinforces the prevalence of positive Epstein-Barr adenocarcinomas in males and high microsatellite instability in females, with a high level of certainty of evidence and low risk of bias in the analyzed studies due to the rigorous methods used.
CONCLUSIONS: The molecular classification proposed by TCGA shows limited dissemination, with MSI-H and EBV+ subtypes being the most researched, probably due to the benefit of the association with immunotherapies. However, the subclassification cannot be restricted to less than a quarter of the cases, and improvements in this aspect are urgent for the construction of knowledge on this important topic of global health.
METHODS: A broad, comprehensive, and reproducible search with methodological rigor was conducted for study selection using the ROBINS-I and GRADEpro protocols and appropriate combinations of keywords.
RESULTS: A total of 25 studies were selected: six with a complete classification similar to TCGA and 19 with a distinction between MSI-H and EBV+. The application of meta-analysis calculations reinforces the prevalence of positive Epstein-Barr adenocarcinomas in males and high microsatellite instability in females, with a high level of certainty of evidence and low risk of bias in the analyzed studies due to the rigorous methods used.
CONCLUSIONS: The molecular classification proposed by TCGA shows limited dissemination, with MSI-H and EBV+ subtypes being the most researched, probably due to the benefit of the association with immunotherapies. However, the subclassification cannot be restricted to less than a quarter of the cases, and improvements in this aspect are urgent for the construction of knowledge on this important topic of global health.
摘要：
背景：胃上皮肿瘤表现出形态学异质性，不同的生物行为，和不同的病理途径。癌症基因组图谱（TCGA）提出了基于遗传和分子发现的胃腺癌的分子分类，这显示了诊断的特殊特征，预后,间接地,治疗替代方案。在这个分类中，爱泼斯坦-巴尔病毒阳性（EBV）和高微卫星不稳定性（MSI-H）亚型是表现出较低侵袭性生物学行为和高度残缺表型的亚型。这项研究进行了系统评价，重点是基于TCGA提出的分子分类的流行病学和预后因素。
方法：广泛，全面,使用ROBINS-I和GRADepro方案以及适当的关键词组合，进行了方法学严谨的可重复搜索，以进行研究选择。
结果：总共选择了25项研究：6项具有与TCGA相似的完整分类，19项具有MSI-H和EBV+之间的区别。荟萃分析计算的应用加强了男性中Epstein-Barr腺癌阳性和女性中微卫星高度不稳定的患病率，由于使用了严格的方法，在分析的研究中具有高度的证据确定性和低偏倚风险。
结论：TCGA提出的分子分类显示传播有限，MSI-H和EBV+亚型是研究最多的，可能是由于与免疫疗法相关的好处。然而,子分类不能限于少于四分之一的案件，这方面的改进对于建立关于全球健康这一重要主题的知识是紧迫的。
方法：广泛，全面,使用ROBINS-I和GRADepro方案以及适当的关键词组合，进行了方法学严谨的可重复搜索，以进行研究选择。
结果：总共选择了25项研究：6项具有与TCGA相似的完整分类，19项具有MSI-H和EBV+之间的区别。荟萃分析计算的应用加强了男性中Epstein-Barr腺癌阳性和女性中微卫星高度不稳定的患病率，由于使用了严格的方法，在分析的研究中具有高度的证据确定性和低偏倚风险。
结论：TCGA提出的分子分类显示传播有限，MSI-H和EBV+亚型是研究最多的，可能是由于与免疫疗法相关的好处。然而,子分类不能限于少于四分之一的案件，这方面的改进对于建立关于全球健康这一重要主题的知识是紧迫的。
