检测微淋巴管及其密度和血管内皮生长因子C对结直肠癌的临床意义

目的探讨检测微淋巴管、微淋巴管密度(LMVD)和血管内皮生长因子C(VEGF-C)的表达对结直肠癌的临床意义。方法应用5′-核苷酸酶(5′-Nase)组织化学、SABC免疫组织化学(免疫组化)和RT-PCR检测80例结直肠癌组织和癌旁组织及30例结直肠正常组织的微淋巴管、LMVD和VEGF-C的表达,并随访、记录患者的临床病理参数和生存资料,分析其相关性。结果(1)结直肠癌、癌旁、正常结直肠组织的微淋巴管均被染成棕黄褐色。结直肠癌组织微淋巴管管腔封闭或无腔,为无功能淋巴管；癌旁组织微淋巴管丰富,管腔大,为功能性淋巴管。(2)癌旁组织LMVD为9．76±2．85,明显高于结直肠正常组织的5．49±．43(t=8．220,P＜0．01)；也高于癌组织的2．13±0．96(t= 15．118,P＜0．001)。(3)结直肠癌VEGF-C蛋白表达阳性率(48．8%)和相对表达量(1．09±1．20)明显高于正常结直肠组织(0和0),与VEGF-C mRNA表达一致；且VEGF-C表达与LMVD相关。(4) LMVD、VEGF-C表达与结直肠癌患者的年龄、性别、肿瘤部位大小、大体组织学类型无关(均P＞0．05)；与Dukes分期(P＜0．0001、P=0．0234)、淋巴结转移(P＜0．0001、P=0．0059)和生存期(P＜0．0001、P＜0．0001)密切相关。LMVD还与分化程度(P=0．0168)和肝肺血行转移(P=0．0088)相关。结论结直肠癌癌旁微淋巴管为功能性淋巴管；癌旁的功能性微淋巴管和增高的LMVD及肿瘤VEGF-C表达,可作为结直肠癌淋巴管生成的形态学特征、分子表型和判断结直肠癌患者淋巴转移及预后的重要指标。

Clinical significance of detection on lymphatic microvessel, lymphatic microvessel density and vascular endothelial growth factor-C in patients with colorectal carcinoma

OBJECTIVE: To evaluate the clinical significance of detection on lymphatic microvessel, lymphatic microvessel density (LMVD) and vascular endothelial growth factor-C (VEGF-C) in patients with colorectal carcinoma. METHODS: Eighty tissue specimens of the colorectal carcinoma and the peritumoral tissue and thirty of adjacent normal bowel tissue were collected. The lymphatic microvessel and LMVD were determined by 5'-nucleotidase histochemical staining. The expression of VEGF-C protein and VEGF-C mRNA in specimens of colorectal carcinoma and normal colorectal tissues were studied by RT-PCR and immunohistochemical methods utilizing strept-avidin-biotin complex. Clinicopathological data and survival of each patient were obtained and analyzed. RESULTS: (1) The brown or filemot stained lymphatic microvessels were observed in specimens from the colorectal carcinoma, the peritumoral tissue and the normal bowel. Collapsed, nonfunctional lymphatic vessels were observed in the intratumoral tissue, and plenty of lymphatic vessels with large lumen referred as functional lymphatic vessels were observed in the peritumoral tissue. (2) The mean value of LMVD in the peritumoral tissue was significantly higher than that in the normal bowel tissue (9.76+/-2.85 vs. 5.49+/-1.43, t=8.220, P<0.01) and tumor tissue (9.76+/-2.85 vs. 2.13+/-0.96, t=15.118, P<0.001). (3) The positive rate (48.8% vs. 0, P<0.01) and mean value (1.09+/-1.20 vs. 0, P<0.01) of the VEGF-C protein expression in colorectal carcinoma specimens were significantly higher than that of the normal bowel tissue. The expression of VEGF-C protein was consistent with the expression of VEGF-C mRNA. The VEGF-C expression in intratumoral tissue demonstrated significant correlation with LMVD in the peritumoral tissue of colorectal carcinoma. (4) Both LMVD in the peritumoral tissue and the expression of VEGF-C in the intratumoral tissue correlated significantly with Dukes' stage (P<0.0001 and P=0.0234), lymph node metastasis (P<0.0001 and P=0.0059), and survival (P<0.0001 and P<0.0001), but not with age, sex, location and dimension of lesion, gross and histological type. Also, there was a positive significant correlation of LMVD in the peritumoral tissue with degree of differentiation (P=0.0168) and metastasis to the liver or the lung (P=0.0088). CONCLUSIONS: Lymphatic microvessels in the peritumoral tissue are functional. The functional lymphatic microvessels, increased LMVD in the peritumoral tissue and the expression of VEGF-C in the intratumoral tissue may act as the morphological features and the molecular phenotype of lymphangiogenesis in colorectal carcinoma, and also as important predictive markers for evaluating lymphatic metastasis and prognosis in patients with colorectal carcinoma.