Although extended colectomy (EC) was recommended for HNPCC patients, previous studies did not show significantly improved overall survival. Immunohistochemical (IHC) stain of mismatch repair (MMR) gene protein expression is now a feasible and reliable test clinically. Therefore, we tried to investigate whether we could use MMR IHC stain to select operation types in HNPCC patients. Between 1995 and 2013, 186 HNPCC patients were collected. Status of MMR protein expression, perioperative clinic-pathological variables and post-operative follow up status were analyzed by multivariate analyses. Sixty-five percent (121 of 186) patients of these HNPCC patients demonstrated loss of at least one MMR protein. There were several significant differences existing between deficient MMR (dMMR) and proficient MMR (pMMR) subgroups in terms of clinic-pathological characteristics. With the average follow-up duration of 93.9 months, we observed significantly high risk of developing metachronous CRC between SC and EC subgroups (crude rate 8.5% vs. 0%, p = 0.035). However, no significant difference was observed among the presence of extra-colonic tumors (12.4% vs. 5.8%, p = 0.284). The positive and negative prediction rate of metachronous CRC in dMMR subgroup was 12.8 and 87.2% while 1.9 and 98.1% in the pMMR subgroup. Survival outcomes were significantly affected by MMR status and resection types by multivariate analysis. Significantly better OS in dMMR subgroup (HR = 0.479, 95% CI: 0.257–0.894, p = 0.021) comparing with pMMR subgroup was observed. However, significant improved DFS (HR = 0.367, 95% CI: 0.172–.0787, p = 0.010) but not significant for OS (HR = 0.510, 95% CI: 0.219–1.150, p = 0.103) for EC subgroup compared with SC subgroup. Differences existing among different subgroups by combing extent of resection and MMR status. In dMMR subgroup, SC, compared with EC, demonstrated significantly worse DFS by multivariate analyses (HR = 3.526, 95% CI: 1.346–9.236, p = 0.010) but not for OS (HR = 2.387, 95% CI: 0.788–7.229, p = 0.124), however, no significantly differences of OS and DFS in pMMR subgroup between SC and EC were found. Significantly better overall survival and higher rate of metachronous CRC exist in dMMR subgroup of HNPCC patients comparing with pMMR subgroup. Extended colectomy significantly improved DFS and was thus recommended for dMMR subgroup but not pMMR subgroup of HNPCC patients.

中文翻译：

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根据遗传性非息肉病性结直肠癌患者的错配修复状态决定手术类型：应该采用量身定制的方法，还是一刀切？

尽管建议对 HNPCC 患者进行扩大结肠切除术 (EC)，但之前的研究并未显示总生存率显着提高。错配修复 (MMR) 基因蛋白表达的免疫组织化学 (IHC) 染色现在是临床上可行且可靠的测试。因此，我们试图研究是否可以使用 MMR IHC 染色来选择 HNPCC 患者的手术类型。1995 年至 2013 年间，共收集了 186 名 HNPCC 患者。MMR 蛋白表达状态、围手术期临床病理变量和术后随访状态通过多变量分析进行分析。这些 HNPCC 患者中有 65%（186 名中的 121 名）表现出至少一种 MMR 蛋白的丢失。在临床病理特征方面，MMR 缺陷 (dMMR) 和 MMR 精通 (pMMR) 亚组之间存在几个显着差异。平均随访时间为 93.9 个月，我们观察到 SC 和 EC 亚组之间发生异时 CRC 的风险显着高（粗率 8.5% 与 0%，p = 0.035）。然而，在存在结肠外肿瘤之间没有观察到显着差异（12.4% 对 5.8%，p = 0.284）。dMMR亚组异时CRC的阳性和阴性预测率为12.8%和87.2%，而pMMR亚组为1.9%和98.1%。通过多变量分析，生存结果受 MMR 状态和切除类型的显着影响。观察到 dMMR 亚组的 OS 显着优于 pMMR 亚组（HR = 0.479，95% CI：0.257–0.894，p = 0.021）。然而，与 SC 亚组相比，EC 亚组的 DFS 显着改善（HR = 0.367，95% CI：0.172–.0787，p = 0.010）但对 OS 不显着（HR = 0.510，95% CI：0.219–1.150，p = 0.103） . 结合切除范围和MMR状态，分析不同亚组间存在的差异。在 dMMR 亚组中，与 EC 相比，SC 通过多变量分析显示出显着更差的 DFS（HR = 3.526，95% CI：1.346–9.236，p = 0.010），但在 OS 方面则不然（HR = 2.387，95% CI：0.788–7.229 , p = 0.124)，然而，未发现 SC 和 EC 之间 pMMR 亚组的 OS 和 DFS 存在显着差异。与pMMR亚组相比，HNPCC患者的dMMR亚组存在显着更好的总生存率和更高的异时CRC发生率。