Chemopreventive Action of Mesalazine on Colorectal Cancer: a Pilot Study for an "in Vivo" Evaluation of the Molecular Effects on β-catenin Signaling Pathway.

Inclusion Criteria: * Patients with precancerous colorectal lesions (polypoid or nonpolypoid adenomas) that needs of an endoscopic exam of control after 3 months from the removal of the lesions (determined on the basis of the morphological and histological characteristics of the lesions and of the removal technique) * Ability and willingness to adhere to study regimen * Written informed consent The following inclusion criteria was deleted according to Amendment n. 01 approved by the Ethical Committee on 19/dec/2014: \- diverticular disease/diverticular colitis; The rationale of this change is that the presence of diverticular disease/diverticular colitis does not contribute to the definition of the trial primary end-points and represents a critical point during the patient selection with an impact on duration and conduction of the study. Exclusion Criteria: * Patients under therapy with Aspirin (\>100 mg/die) or other FANS * Inflammatory bowel disease (IBD) * Hypersensitivity to Mesalazine. * Pregnant or nursing (lactating) women * Patients who belonging to the category n. 4 of the ASA physical status classification system * contraindications to mesalazine therapy