Surgical and Medical Department of the Clinical Sciences, Biomedical Technologies and Translational Medicine, Sant'Andrea Hospital, Faculty of Medicine and Psychology University of Rome "La Sapienza", Via di Grottarossa, 1035-39, 00189 Rome, Italy.
Int J Surg. 2013;11(9):1016-21. doi: 10.1016/j.ijsu.2013.05.031. Epub 2013 Jun 6.
The presence of high microsatellite instability (MSI-H) in colorectal cancers has been generally associated with better survival, opposite an increased ratio between metastatic lymph-nodes and nodes sampled in the specimen (LNR) has been associated with a worse outcome. The study aims to detect the incidence and prognostic significance of MSI and LNR in a consecutive series of 119 colorectal cancers.
119 consecutive colorectal cancer patients undergone resection at our Department were enrolled from 2000 to 2004. The MSI status has been evaluated by amplification of target sequences. The LNR has been calculated and patients stratified into 4 groups on the basis of the ratio values. Clinical/pathological data were collected and analyzed; the overall, disease free and disease specific survivals were analyzed by the Kaplan-Meier and Cox regression analyses (mean follow-up: 81 months).
MSI-H was detected in 11.7% of the cases and patients were compared with the microsatellite stable (MSS) group. We observed a higher prevalence of right colon localizations (p 0.01) and locally advanced tumors (p 0.0012) in the MSI-H subgroup. Kaplan-Meier analysis documented no significant difference comparing MSS patients vs MSI-H, although the latter showed a better survival trend (p ns); worse survivals were observed according with the LNR stratification (p < 0.0001). Multivariate analysis documented a statistical value associated with the LNR sub-groups in relationship with survival.
According to our results the MSI-H status was associated with particular features (right locations/locally advanced tumors). The results of a long-term follow-up indicate a trend for better survival in MSI-H vs MSS patients. Notably, an increased LNR is associated with worse survivals, both at the univariate and multivariate analysis, displaying this ratio as the strongest prognostic factor of cancer-related survival.
结直肠癌中存在高微卫星不稳定性（MSI-H）通常与更好的生存相关，而转移淋巴结与标本中采样淋巴结的比值（LNR）增加则与更差的预后相关。本研究旨在检测连续 119 例结直肠癌中 MSI 和 LNR 的发生率及其预后意义。
2000 年至 2004 年，我们科室连续收治了 119 例结直肠癌患者。通过扩增靶序列来评估 MSI 状态。计算 LNR 并根据比值值将患者分为 4 组。收集并分析临床/病理数据；通过 Kaplan-Meier 和 Cox 回归分析（平均随访：81 个月）分析总生存、无病生存和疾病特异性生存。
在 11.7%的病例中检测到 MSI-H，将这些患者与微卫星稳定（MSS）组进行比较。我们观察到 MSI-H 亚组中右半结肠定位（p 0.01）和局部晚期肿瘤（p 0.0012）的发生率较高。Kaplan-Meier 分析显示 MSS 患者与 MSI-H 患者之间无显著差异，尽管后者的生存趋势较好（p ns）；根据 LNR 分层，生存情况较差（p < 0.0001）。多变量分析记录了与生存相关的 LNR 亚组的统计学值。
根据我们的结果，MSI-H 状态与特定特征（右半结肠定位/局部晚期肿瘤）相关。长期随访结果表明，MSI-H 患者的生存趋势优于 MSS 患者。值得注意的是，LNR 增加与生存不良相关，无论是单因素还是多因素分析，均显示该比值是癌症相关生存的最强预后因素。
