Abstract

Angiogenesis is a crucial step in tumor growth and progression. Scarce data is available on angiogensis in gastrointestinal tumors. We studied 16 normal colon, 44 adenomas and 29 carcinomas to evaluate angiogenesis in colorectal tumors and to assess the correlation among p53 protein, proliferative activity and other clinical prognostic parameters. Endothelial cells were immunostained with an anti-Factor VIII mAb; in each case three microscopic fields(x 200) were counted: average number of the three fields was defined as microvessel density (MVD). p53 protein expression was 45.5%(20/44) in adenomas, and 79.3%(23/29) in carcinomas (p<0.01). p53 protein expression of carcinomas was 57.1%(4/7) in diploid tumors, 100%(8/8) in aneuploid tumors (p=0.07), 100%(8/8) in well differentiated tumors, and 50%(2/4) in poorly differentiated tumors (p=0.09). MIB-1 score was 2.3+/-0.7(38) in adenomas, 3.4+/-0.5(29) in carcinomas (p<0.01). There was no significant correlation between p53 protein and MIB-1 score. MVD was 10.4+/-4.1(16) in the normal mucosa, 21.5+/-7.9(39) in the adenomas, 35.3+/-9.7(26) in carcinomas (normal versus adenomas, p<0.01; adenomas versus carcinomas, p<0.01). MVD was 25.8+/-5.4(2) in carcinomas confined to mucosa, and 36.1+/-9.6(24) in carcinomas with transmural invasion. The higher MIB-1 score was in carcinomas the more MVD increased but there was no statistical significance (r=0.38, p=0.055). MVD of carcinomas was not associated with nodal metastasis, p53 expression, and DNA ploidy. p53 protein and MIB-1 expression are useful methods for the evaluation of malignancy, and tumor angiogenesis is an early event in a colorectal tumor but MVD does not correlate with prognostic parameters except for the tumor depth.

• Keywords: Microvessel Density;p53 protein;MIB-1;Colorectal tumor