Department of Surgical Oncology and General Surgery, The First Hospital of China Medical University, Shenyang, People's Republic of China.
Ann Surg Oncol. 2011 Sep;18(9):2453-60. doi: 10.1245/s10434-011-1687-2. Epub 2011 Apr 1.
Lymph node ratio (LNR) has been reported to represent a powerful independent prognostic value in some malignancies. The significance of LNR in colorectal cancer is still under debate.
A total of 505 patients with stage III colorectal cancer were reviewed. Using running log-rank statistics, we calculated the best cutoff values for LNRs and proposed a novel rN category: rN1, 0% < LNR ≤ 35%; rN2, 35% < LNR ≤ 69%; and rN3, LNR > 69%. A Spearman's correlation coefficient test was used to assess the correlation between the number of retrieved nodes and the number of metastatic nodes, as well as the number of retrieved nodes and the LNRs. Univariate and two-step multivariate analyses were performed, respectively, to identify the significant prognostic clinicopathologic factors.
The 5-year overall survival rate decreased significantly with increasing LNRs: rN(1) = 61% survival rate, rN(2) = 30.3% survival rate, and rN(3) = 11.2% survival rate (P < 0.001). Univariate and two-step multivariate analyses identified the rN category as a significant prognostic factor no matter whether the minimum number of LNs retrieved was met. There was a significant prognostic difference among different rN categories for any pN category, but no apparent prognostic difference was seen between different pN categories in any rN category. Moreover, marked heterogeneity could be seen within III(a-c) substages when survival was compared among rN(1-3) categories but not between pN(1-2) categories.
rN categories have more potential for predicting patient outcomes and are superior to the UICC/AJCC pN categories. We recommend rN categories for prognostic assessment and rN categories should be reported routinely in histopathological reports.
淋巴结比率（LNR）已被报道在某些恶性肿瘤中代表着强大的独立预后价值。LNR 在结直肠癌中的意义仍存在争议。
回顾了 505 例 III 期结直肠癌患者。使用运行对数秩检验，我们计算了 LNR 的最佳截断值，并提出了一个新的 rN 分类：rN1，0%<LNR≤35%；rN2，35%<LNR≤69%；rN3，LNR>69%。采用 Spearman 相关系数检验评估了检索到的淋巴结数量与转移淋巴结数量之间的相关性，以及检索到的淋巴结数量与 LNR 之间的相关性。分别进行单因素和两步多因素分析，以确定有意义的预后临床病理因素。
随着 LNR 的增加，5 年总生存率显著下降：rN(1)=61%生存率，rN(2)=30.3%生存率，rN(3)=11.2%生存率（P<0.001）。单因素和两步多因素分析均表明，无论是否达到最小淋巴结检出数，rN 分类都是一个显著的预后因素。对于任何 pN 分类，不同 rN 分类之间均存在显著的预后差异，但对于任何 rN 分类，不同 pN 分类之间无明显的预后差异。此外，当比较 rN(1-3)分类之间的生存情况时，在 III(a-c)亚分期内存在明显的异质性，但在 pN(1-2)分类之间不存在明显的异质性。
rN 分类在预测患者预后方面具有更大的潜力，优于 UICC/AJCC pN 分类。我们建议 rN 分类用于预后评估，rN 分类应在组织病理学报告中常规报告。
