目前尚不清楚对于生物学上不同的缺陷配对修复 (dMMR) 转移性结直肠癌 (mCRC) 患者的根治性局部治疗是否与对熟练的配对修复 (pMMR) mCRC 患者具有相似的益处。在这项全国范围的研究中，分析了2015年至2018年接受根治性局部治疗转移的 dMMR 与 pMMR mCRC 患者的无复发生存 (RFS) 和总体生存 (OS)。对结直肠肝转移 (CRLM) 的切除和细胞减少手术 ± 腹腔热疗化疗 (CRS ± HIPEC) 进行了亚组分析。进行了多变量回归分析。对于 dMMR 肿瘤患者，中位 RFS 为 11.1 个月 [95% 置信区间 (CI) 8.5-41.1 个月]，而 pMMR 肿瘤患者的中位 RFS 为 8.9 个月 (95% CI 8.1-9.8 个月)。与 pMMR 肿瘤相比，两年 RFS 在 dMMR 患者中更高 (43% vs. 21%)。在局部治疗亚组 (CRLM 和 CRS ± HIPEC) 中的结果相似。缺陷配对修复与 pMMR mCRC 患者之间的特征存在显著差异，但多变量分析仍显示 dMMR 是改善 RFS 的独立因素 (风险比例 [HR]：0.57，95% CI 0.38-0.87)。dMMR mCRC 的中位 OS 为 33.3 个月，而 pMMR mCRC 的中位 OS 为 43.5 个月，主要是由于 dMMR 在免疫治疗时代出现复发时的存活率较差。符合根治性局部治疗转移条件的 dMMR 患者的 RFS 与 pMMR 患者相当或更有利，且有相当比例的患者仍然无复发。这支持在 dMMR mCRC 患者中将局部治疗作为一种有价值的治疗选择，并可用于关于首选局部治疗还是免疫治疗的共同决策。© 2023. 作者。

It is unclear whether curative-intent local therapy of metastases is of similar benefit for the biological distinct subgroup of patients with deficient mismatch repair (dMMR) metastatic colorectal cancer (mCRC) compared with proficient mismatch repair (pMMR) mCRC.In this nationwide study, recurrence-free (RFS) and overall survival (OS) were analyzed in patients with dMMR versus pMMR mCRC who underwent curative-intent local treatment of metastases between 2015 and 2018. Subgroup analyses were performed for resection of colorectal liver metastases (CRLM) and cytoreductive surgery ± hyperthermic intraperitoneal chemotherapy (CRS ± HIPEC). Multivariable regression was conducted.Median RFS was 11.1 months [95% confidence interval (CI) 8.5-41.1 months] for patients with dMMR tumors compared with 8.9 months (95% CI 8.1-9.8 months) for pMMR tumors. Two-year RFS was higher in patients with dMMR versus pMMR (43% vs. 21%). Results were similar within subgroups of local treatment (CRLM and CRS ± HIPEC). Characteristics differed significantly between patients with dMMR and pMMR mCRC; however, multivariable analysis continued to demonstrate dMMR as independent factor for improved RFS [hazard ratio (HR): 0.57, 95% CI 0.38-0.87]. Median OS was 33.3 months for dMMR mCRC compared with 43.5 months for pMMR mCRC, mainly due to poor survival of patients with dMMR in cases of recurrence in the preimmunotherapy era.Patients with dMMR eligible for curative-intent local treatment of metastases showed a comparable to more favorable RFS compared with patients with pMMR, with a clinically relevant proportion of patients remaining free of recurrence. This supports local treatment as a valuable treatment option in patients with dMMR mCRC and can aid in shared decision-making regarding upfront local therapy versus immunotherapy.© 2023. The Author(s).