The Correlation Of Vegf-c Expression And Micro-vessel Density With Lymphatic Metastasis In Melanoma

Objective: To investigate the expression of vascular endothelial growth factor C (VEGF-C) and lymphatic micro-vessel density and their relationship to lymph node metastasis and other clinicopathological features in human melanoma tissues, in order to find some clinical indicators that can be easy detected to predict lymph node metastasis and prognosis.Methods: Surgical resection specimens of twenty-four patients with melanoma from January 2003 to June 2009 were collected. Eleven cases of nevi were used as control. The expression of VEGF-C protein and D2-40 in melanoma tissues were determined by immunohistochemical EnVision technique,and the lymphatic micro-vessel density counted by D2-40 positive vessels was evaluated. The relation between VEGF-C and lymphatic micro-vessel density and clinicopathological features of melanoma was analyzed. The correlation between VEGF-C and lymphatic micro-vessel density was discussed. The survival analysis with the follow-up materials was studied and their effects on metastasis-free survival rate in melanoma were separately explored.Results: (1) Lymphatic micro-vessel density was 14.30±4.91 in melanoma and 7.64±3.08 in nevi. The difference has great significance (P <0.01) .(2)Lymphatic micro-vessel density was closely correlated with the presence of ulcer, but not related to age, sex, Clark grading,Breslow layers and vascular invasion (P> 0.05), Lymphatic micro-vessel density in ulcer group was higher than that in non-ulcer group(P = 0.005). (3)The positive expression rates of VEGF-C in melanoma were 100%.Among them, 20.8% (5 / 24) were weak expression, 33.4% (8 / 24) were medium expression, and 45.8% (11/24) were strong expression. There was no significant correlation among VEGF-C expression, age, sex, ulcer, Clark grading, Breslow layers and vascular invasion (P> 0.05). (4) Lymphatic micro-vessel density in group that VEGF-C weak and medium expression was lower than the strong expression group, but no correlation was found between them by using spearman rank correlation(r=0.278,P=0.188). (5)Survival analysis showed that the metastasis-free survival rate in patients with melanoma whose lymphatic micro-vessel density was greater than or equal to 14.7 was significantly shorter than those that is less than 14.7 (χ2 = 3.891, P = 0.049).No influence of VEGF-C expression to the metastasis-free survival rate was found (P> 0.05).Conclusion: (1) D2-40 was labeled for lymphatic endothelium with high specificity and sensitivity and can be widely used in studies of lymphatic vessels. The metastasis-free survival rate may be chosen in the analysis of prognostic factors associated with metastasis. (2)Lymphatic micro-vessel density is positively related to ulcer. (3) Lymphatic micro-vessel density in melanoma is significantly higher than that in nevi. Lymphatic micro-vessel density may be related to the occurrence of melanoma. The expression of VEGF-C has no correlation with Lymphatic micro-vessel density. (4) Tumor lymphangiogenesis may be an important factor for lymph node metastasis is involved in the infiltration of melanoma. Lymphatic micro-vessel density is related to lymph node metastasis. Lymphatic micro-vessel density is expected to be essential prediction of melanoma lymph node metastasis and prognosis.