It is thought that dysregulation of E-cadherin, syndecan-1 (CD138) and Ets-1 is involved in carcinoma development. E-cadherin is an important epithelial cell adhesion molecule; syndecan-1 (CD138) is a regulatory proteoglycan in both cell-cell and cell-matrix adhesion and Ets-1 is a proto-oncogene and transcription factor, which takes part in extracellular matrix remodeling. Our goal was to study the changes in the expression of these molecules during colon carcinoma development and progression. We tested 117 colon adenomas and 149 de novo and ex adenoma carcinomas of the colon, using the Ultravision Polymer system. The positive reaction rate was 100% for E-cadherin, 98.3% for syndecan-1 and 22.4% for Ets-1 in adenomas, while in carcinomas it was 88.5%, 62.4% and 56.3% respectively. We found decreasing expression of E-cadherin and syndecan-1 throughout colon carcinoma progression and an opposite regulation for the Ets-1 protein. Decrease in expression of syndecan-1 is more pronounced in carcinomas compared to E-cadherin. De novo carcinomas have lower E-cadherin and syndecan-1 expression, and higher Ets-1 expression compared to ex adenoma carcinomas. These findings support the hypothesis that there are differences in the carcinogenesis of these tumors.