Institute of Pathology, Klinikum Augsburg, Stenglinstrasse 2, 86156 Augsburg, Germany.
Int J Colorectal Dis. 2013 Jul;28(7):977-83. doi: 10.1007/s00384-012-1636-y. Epub 2013 Jan 12.
Minimal lymph node involvement is a potential prognostic factor in colorectal cancer. The International Union Against Cancer defined tumour deposits between 0.2 and 2 mm as micrometastases and clusters and single-cell infiltrations below this cutoff as isolated tumour cells. Nevertheless, only a minority of studies discriminated metastatic involvements according to this definition.
In order to investigate the prognostic significance of micrometastases (0.2-2 mm), we performed a retrospective study enrolling 44 routinely diagnosed micrometastatic cases within 15 years which represent about 1% of our cases. These cases have been re-evaluated.
Seven of the micrometastatic cases turned out to be macrometastases after step sectioning. Complete follow-up was available in 33 remaining cases. Collections of node-negative and macrometastatic cases served as control groups. The Kaplan-Meier curves of macro- and micrometastatic cases showed a similar adverse course (p = 0.830) especially during the first 40 months. The 5-year-survival rates were 51, 60 and 64 months for macro-, micrometastatic and node-negative cases, respectively. The difference in overall survival, however, reached only a statistical trend and was not significant (p = 0.137). After re-evaluation with step sections and cytokeratin immunohistochemistry out of an initial 91 node-negative cases, 11 (12%) cases were identified with isolated tumour cells and one (1%) case with a micrometastasis.
Our data show that micro- and macrometastatic colorectal cancers show very similar survival rates. Therefore, efforts to improve the detection of lymph node micrometastases seem to be justified.
淋巴结微小浸润是结直肠癌的一个潜在预后因素。国际抗癌联盟（UICC）将直径在 0.2 至 2 毫米之间的肿瘤沉积物定义为微转移灶，而直径小于该值的肿瘤细胞簇和单个细胞浸润则定义为孤立肿瘤细胞。然而，只有少数研究根据这一定义区分转移性浸润。
为了研究微转移灶（0.2-2 毫米）的预后意义，我们进行了一项回顾性研究，纳入了 15 年内诊断的 44 例常规微转移病例，约占我们病例的 1%。这些病例已重新评估。
在进行连续切片后，7 例微转移病例中有 6 例被证实为宏转移。33 例其余病例可获得完整随访。无淋巴结转移和宏转移病例的集合作为对照组。宏转移和微转移病例的 Kaplan-Meier 曲线显示出相似的不良病程（p=0.830），特别是在前 40 个月。宏转移、微转移和无淋巴结转移病例的 5 年生存率分别为 51%、60%和 64%。然而，总生存率的差异仅达到统计学趋势，无统计学意义（p=0.137）。在对 91 例初始无淋巴结转移病例进行连续切片和细胞角蛋白免疫组化重新评估后，发现 11 例（12%）病例存在孤立肿瘤细胞，1 例（1%）病例存在微转移灶。
我们的数据表明，微转移和宏转移结直肠癌的生存率非常相似。因此，努力提高淋巴结微转移的检测似乎是合理的。
