Methods: We retrospectively and cross-sectionally reviewed the cases of 648 patients with a histological diagnosis of colon adenocarcinoma. Of these, 166 had partial molecular studies, and 42 cases were selected based on the availability of the genetic markers targeted in this study. We analyzed the frequency of mutations in these genes, as well as their correlation with microsatellite instability (MSI). Results: A high mutation rate was found in theKRASgene (52.4%).NRASmutations were less frequent (8.9%), whereasBRAFmutations were observed in 20.8% of cases. This allowed us to identify a patient subgroup with MSI, representing 12.1% of cases. Among the 42 patients analyzed forKRAS,NRAS,BRAF, and MSI mutations, a significant association was observed betweenKRASmutations and microsatellite stability, while no association was found betweenNRASmutations and MSI.BRAFmutations showed a statistically significant association with MSI (p< 0.05), with the most common mutation being c.1799T > A,p.Val600Glu. The objective of this study is to demonstrate that the NGS-based method for evaluating MSI is rigorously valid compared to the results obtained using IHC and PCR. Conclusions: Comprehensive NGS profiling from the start improves diagnostic efficiency by saving time, tissue, and costs compared to gene-by-gene analysis. It also enables better molecular characterization and facilitates tailored therapeutic strategies, particularly in identifying candidates for targeted therapy and immunotherapy. This approach supports efficient tumor classification based on usingKRAS,BRAF,NTRK,ERBB2, andPIK3CAas key markers, along with MSI status. We recommend that, if initial NGS is not feasible, start withKRASanalysis, then testBRAFand MSI if no mutation is found.
方法：我们回顾性、横断面地分析了648例经组织学诊断为结肠腺癌的病例。其中，166例进行了部分分子研究，根据本研究靶向的遗传标记物的可及性，筛选出42例。我们分析了这些基因的突变频率，以及它们与微卫星不稳定性（MSI）的相关性。结果：发现KRAS基因突变率较高（52.4%）。NRAS突变较少见（8.9%），而BRAF突变在20.8%的病例中观察到。这使得我们识别出一个MSI患者亚组，占病例的12.1%。在分析KRAS、NRAS、BRAF和MSI突变的42例患者中，观察到KRAS突变与微卫星稳定性之间存在显著关联，而NRAS突变与MSI之间未发现关联。BRAF突变与MSI显示出统计学上的显著关联（p < 0.05），最常见的突变是c.1799T > A, p.Val600Glu。本研究旨在证明，与使用免疫组化（IHC）和聚合酶链反应（PCR）获得的结果相比，基于二代测序（NGS）的MSI评估方法具有严格的效度。结论：与逐个基因分析相比，从一开始就进行全面的NGS分析，通过节省时间、组织样本和成本，提高了诊断效率。它还能实现更好的分子特征描述，并有助于制定个体化治疗策略，特别是在识别靶向治疗和免疫治疗的候选者方面。这种方法支持基于使用KRAS、BRAF、NTRK、ERBB2和PIK3CA作为关键标记物以及MSI状态进行高效的肿瘤分类。我们建议，如果初始NGS不可行，则从KRAS分析开始，如果未发现突变，则检测BRAF和MSI。
肿瘤(癌症)患者之家