Department of Gastrointestinal Surgery, Oslo University Hospital-Aker, Oslo, Norway.
Ann Oncol. 2013 May;24(5):1274-82. doi: 10.1093/annonc/mds614. Epub 2012 Dec 12.
Microsatellite instability (MSI) was suggested as a marker for good prognosis in colorectal cancer in 1993 and a systematic review from 2005 and a meta-analysis from 2010 support the initial observation. We here assess the prognostic impact and prevalence of MSI in different stages in a consecutive, population-based series from a single hospital in Oslo, Norway.
Of 1274 patients, 952 underwent major resection of which 805 were included in analyses of MSI prevalence and 613 with complete resection in analyses of outcome. Formalin-fixed tumor tissue was used for PCR-based MSI analyses.
The overall prevalence of MSI was 14%, highest in females (19%) and in proximal colon cancer (29%). Five-year relapse-free survival (5-year RFS) was 67% and 55% (P = 0.030) in patients with MSI and MSS tumors, respectively, with the hazard ratio (HR) equal to 1.60 (P = 0.045) in multivariate analysis. The improved outcome was confined to stage II patients who had 5-year RFS of 74% and 56% respectively (P = 0.010), HR = 2.02 (P = 0.040). Examination of 12 or more lymph nodes was significantly associated with proximal tumor location (P < 0.001).
MSI has an independent positive prognostic impact on stage II colorectal cancer patients after complete resection.
1993 年，微卫星不稳定性（MSI）被认为是结直肠癌预后良好的标志物，2005 年的系统评价和 2010 年的荟萃分析支持了这一最初的观察结果。我们在此评估了 MSI 在挪威奥斯陆一家医院连续的基于人群的系列中不同分期的预后影响和流行率。
在 1274 名患者中，952 名接受了主要切除术，其中 805 名患者接受了 MSI 流行率分析，613 名患者接受了完全切除术的生存分析。福尔马林固定的肿瘤组织用于基于 PCR 的 MSI 分析。
总体 MSI 流行率为 14%，女性（19%）和近端结肠癌（29%）最高。MSI 和 MSS 肿瘤患者的 5 年无复发生存率（5 年 RFS）分别为 67%和 55%（P = 0.030），多变量分析的危险比（HR）等于 1.60（P = 0.045）。改善的结果仅限于 II 期患者，他们的 5 年 RFS 分别为 74%和 56%（P = 0.010），HR = 2.02（P = 0.040）。检查 12 个或更多的淋巴结与肿瘤位于近端显著相关（P < 0.001）。
在完全切除后，MSI 对 II 期结直肠癌患者具有独立的积极预后影响。
