Structural alterations of c-myb proto-oncogenes and serum p53 mutant level, Mitomycin C-induced chromosomal aberrations and sister chromatid exchanges and proliferative activity of mucosa (H3-thymidine -labeling index LI) are often determined to obtain more information about the diagnosis and prognosis of neoplastic and preneoplastic lesions of the colon. The aim of this study was to evaluate the endoscopic findings of a 5 year follow-up in three groups of subjects (normal, adenoma or cancer patients) and to correlate these findings with the biological alterations in the same subjects between 1990 and 1993. We analyzed 200 subjects (118 Male and 82 Female), 78 normal subjects (group A), 60 patients with adenoma (group B) and 62 with carcinoma (group C). Data regarding endoscopic lesions was collected from June 1998 to December 2000 after a 5 year follow-up and correlated with the biological alterations in the same subjects between 1990--1993. We obtained endoscopic findings from 23/137 subjects (16.8%), 6/137 (4.4%) died from other causes and 108/137 (78.8 %) were negative for lesions. The percentage of disease after 5 years is not statistically different among the three groups (groups A, B and C). There was no statistically significant association between values of the labeling index, structural alterations of c-myb, p-53-M serum levels and chromosomal aberrations and endoscopic findings in the 5 year follow-up. We conclude that the biological markers considered are not able to stratify patients in terms of risk of progression to malignant disease.