微淋巴管密度对直肠癌手术远端切除长度的临床意义

目的研究低位直肠癌的微淋巴管密度（LVD）与直肠癌远端扩散（DIS）长度的关系，探讨LVD在低位直肠癌手术时对决定远端切除长度的价值。方法92例低位直肠癌手术标本通过苏木精．伊红染色测定DIS，利用淋巴管内皮细胞透明质酸受体（LYVE-1）免疫组织化学法测定LVD，分析LVD与DIS及直肠癌其他临床病理学因素间的关系。结果44例（47．8％）患者有DIS，为（0．31±0．09）cm；其中有23例（52．3％）淋巴管内癌栓。癌缘LVD明显高于癌内，DIS组明显高于无DIS组。相关分析显示，DIS组中，癌缘LVD与DIS呈正相关（r=0．755，P〈0．01）；当癌缘LVD超过38时，DIS均超过1cm。LVD还与浸润程度、淋巴结转移和淋巴浸润有关。结论淋巴管内癌栓是直肠癌DIS的主要形式．LVD与DIS的相关关系有助于决定低位直肠癌手术中的远端切除长度。

Clinical significance of lymphatic vessel density in determining the length of distal resection in rectal cancer]

OBJECTIVE: To study the the relationship between lymphatic vessel density (LVD) and distal intramural spread (DIS), and evaluate the value of LVD in determining the length of distal resection in low rectal cancer. METHODS: Ninety-two samples from patients undergone curative resection of low rectal cancer were studied. DIS was detected by HE stain. LVD was examined by immunohisto-chemical LYVE-1 (lymphatic vessel endothelial hyaluronan receptor). The association of LVD with DIS and other clinicopathological factors were examined. RESULTS: DIS (range 0.1-2.4 cm, mean 0.31 cm) was present in 44(47.8%) patients with low rectal cancer, including 23(52.3%) cases with cancer emboli in lymphatic vessels. LVD of peritumoral lesion was significantly higher than that of intratumoral lesion. LVD of DIS subgroup was significantly higher than that of non-DIS subgroup. Positive correlation was found by rank correlation test between the length of DIS and the LVD at peritumor tissue in DIS group (n=44, r=0.755, P<0.01). LVD was also positively correlated with the infiltration extent, lymphatic invasion and lymph node metastasis. CONCLUSIONS: Lymphangiogenesis plays an important role in rectal cancer metastasis and cancer emboli in lymphatic vessels is the most common modality of DIS. The LVD is positively correlated with DIS, which may be helpful to determine the distal clearance length of rectal cancer.