A deficient DNA mismatch repair (MMR) system is identified in a non-negligible part of sporadic colorectal cancers (CRCs), and its prognostic value remains controversial. High tumor mutational burden, along with a poor response to conventional chemotherapy and excellent results from immunotherapy, are the main features of this subset. The aim of this study was to evaluate the predictive value of DNA MMR system status for its best treatment. Four hundred and three CRC patients, operated on from 2014 to 2021 and not treated with immunotherapy, entered this study. Immunohistochemistry and polymerase chain reaction, as appropriate, were used to unequivocally group specimens into microsatellite stable (MSS) and instable (MSI) tumors. The win-ratio approach was utilized to compare composite outcomes. MSI tumors accounted for 12.9% of all series. The right tumor location represented the most important factor related to MSI. The status of the DNA MMR system did not appear to correlate with outcome in early-stage CRCs not requiring adjuvant treatment; in advanced stages undergoing conventional chemotherapy, MSI tumors showed significantly poorer overall and disease-free survival rates and the highest win ratio instead. The determination of DNA MMR status is crucial to recommending correct management. There is clear evidence that instable CRCs needing adjuvant therapy should undergo appropriate treatments.
在相当一部分散发性结直肠癌（CRCs）中，DNA错配修复（MMR）系统存在缺陷，但其预后价值仍存争议。高肿瘤突变负荷、对传统化疗反应不佳以及免疫治疗疗效显著，是该亚型的主要特征。本研究旨在评估DNA MMR系统状态对最佳治疗方案的预测价值。研究纳入了2014年至2021年间接受手术且未进行免疫治疗的403例CRC患者。通过免疫组化及聚合酶链反应检测，将标本明确分为微卫星稳定（MSS）型与微卫星不稳定（MSI）型肿瘤。采用胜率比法比较复合结局指标。MSI肿瘤占全部病例的12.9%，其中右半结肠肿瘤是与MSI相关的最重要因素。在无需辅助治疗的早期CRC中，DNA MMR系统状态与预后未见明显关联；而在接受传统化疗的晚期病例中，MSI肿瘤的总生存率和无病生存率显著更低，胜率比反而最高。DNA MMR状态的检测对制定正确治疗方案至关重要。明确证据表明，需要辅助治疗的不稳定型CRC应接受针对性治疗。
肿瘤(癌症)患者之家