Department of Surgery, Kurume University School of Medicine, Fukuoka, Japan.
Ann Surg. 2011 Apr;253(4):704-10. doi: 10.1097/SLA.0b013e3182119331.
The aim of this study was to emphasize the importance of a subclassification in the TNM staging system of rectal cancer.
The clinical significance of the mesorectal extension of rectal cancer is unclear.
Data from 463 consecutive patients with stage IIa disease (T3N0) undergoing curative surgery at 28 institutes were analyzed. The measurement of the distance of the mesorectal extension (DME) was histologically evaluated. Risk factors for recurrence, for the optimal cutoff point of the DME, independent prognostic factors, and for survivals were studied using receiver operating characteristic curve and logistic and Cox regression analyses. Survivals were calculated using the Kaplan-Meier method.
A value of 4 mm was determined as the optimal cutoff point. The patients were subdivided into 2 groups: DME ≤ 4 mm and DME > 4 mm at the optimal cutoff point. DME > 4 mm had the greatest impact on recurrence-free survival [P = 0.00023, hazard ratio (HR): 2.26, 95% confidence interval (95% CI): 1.465-3.492, L/U ratio: 0.420] and was an independent adverse prognostic factor (P = 0.00323, HR: 1.97, 95% CI: 1.254-3.091). The distant metastasis rate in DME > 4 mm was higher 16.7% than that in DME ≤ 4 mm (P = 0.00177, OR: 2.61, 95% CI: 1.430-4.761). The incidence of local recurrence was not influenced by DME. The recurrence-free 5-year survival rate in DME ≤ 4 mm was significantly better than that in DME > 4 mm (86.6% vs 71.3%, P = 0.00015, HR: 0.44, 95% CI: 0.286-0.683). The cancer-specific survival rate in DME ≤ 4 mm was also significantly better than that in DME > 4 mm (91.3% vs 82.2%, P = 0.000664, HR: 0.52, 95% CI: 0.325-0.843).
A subclassification according to mesorectal extension based on a 4-mm cutoff point is needed for the TNM staging system. However, further prospective study is necessary to prove reproducibility and validity of the cutoff point.
本研究旨在强调直肠癌 TNM 分期系统中进行亚分类的重要性。
直肠癌中直肠系膜延伸的临床意义尚不清楚。
对 28 家机构接受根治性手术的 463 例 IIa 期（T3N0）患者的数据进行分析。采用组织学评估测量直肠系膜延伸的距离（DME）。使用接收者操作特征曲线、逻辑和 Cox 回归分析研究复发的危险因素、DME 的最佳截断值、独立预后因素和生存率。使用 Kaplan-Meier 方法计算生存率。
确定 4mm 为最佳截断值。将患者分为 2 组：DME≤4mm 和 DME＞4mm 在最佳截断值处。DME＞4mm 对无复发生存率的影响最大[P=0.00023，风险比（HR）：2.26，95%置信区间（95%CI）：1.465-3.492，L/U 比：0.420]，是独立的不良预后因素（P=0.00323，HR：1.97，95%CI：1.254-3.091）。DME＞4mm 的远处转移率为 16.7%，高于 DME≤4mm（P=0.00177，OR：2.61，95%CI：1.430-4.761）。DME 对局部复发的发生率没有影响。DME≤4mm 的无复发生存率 5 年明显优于 DME＞4mm（86.6%比 71.3%，P=0.00015，HR：0.44，95%CI：0.286-0.683）。DME≤4mm 的癌症特异性生存率也明显优于 DME＞4mm（91.3%比 82.2%，P=0.000664，HR：0.52，95%CI：0.325-0.843）。
需要根据 4mm 截断值对直肠系膜延伸进行基于亚分类的 TNM 分期系统。然而，需要进一步的前瞻性研究来证明该截断值的可重复性和有效性。
