Expression And Significance Of VEGF, Ang-2 In Rectal Cancer And Their Relationships With Tumor Angiogenesis

OBJECTIVE: To detect the expression of VEGF and Ang-2 in rectal carcinoma tissues, rectal adenoma tissues and normal tissues , investigate its relationship with clinicopathlolgic factors and mcrovessel density (MVD) in tumor tissue.METHODS: VEGF, Ang-2 and factorⅧrelated antigen were stained immunohistochemically in 60 cases of primary rectal cancer, 30 cases of rectal adenoma and 10cases of normal paraneoplastic rectal mucosal tissue, and MVD was also assayed in above tissue specimens.RESULTS: The positive expression rates of VEGF in rectal carcinoma tissues, rectal adenoma tissues and normal tissues were 71.7%, 43.3% and 30% respectively, while the positive expression rates of Ang-2 were 73.3%, 46.7%, 30%. The positive expression of VEGF did not have correlations with gender, age, tumor morphology and location, CEA, differentiation (P>0.05), but had a correlation with rectal cancer clinical stage, lymph node metastasis and metastasis from blood vessels (P < 0.05), The positive expression of Ang-2 did not have correlations with gender, age, tumor morphology and location, CEA, lymph node metastasis (P>0.05), but had a correlation with differentiation, rectal cancer clinical stage and metastasis from blood vessels (P<0.05), The high positive expression of VEGF and Ang-2 had a significant positive correlation in rectal cancer (r = 0.290, P< 0.05). The MVD in cases of the VEGF- positive group was higher compared to the negative group (11.04±1.68 vs7.66±1.22, t= 7.53, P<0.05), the MVD in cases of the Ang-2- positive group was higher compared to the negative group (10.97±1.73 vs7.66±1.31, t= 6.95, P<0.05).CONCLUSION: The overexpression of VEGF and Ang-2 may be related to the development, invasion and metastasis of rectal cancer, they may play synergistic role in angiogenesis.