ABSTRACT
Objectives:
Determine immunohistochemical expression of Phosphatase and tensin homolog (PTEN), Phosphatidylinositol 3 kinase (PI3K), Cycloxygenase-2 (COX2) and one proliferation marker (Ki67) in colorectal polyps and correlate with clinical and pathological data in search of carcinogenic pathways.
Methods:
The reports of 297 polyps diagnosed through endoscopy were reviewed for parameters including age, gender, prior colorectal cancer, the presence of multiple polyps, and polyps’ location, appearance and size. Was conducted a microscopic morphometric computerized analysis of immunohistochemical expression using, the selected antibodies and correlated with clinical and pathological variables.
Results:
The tissue immunohistochemical expression was higher in right colon polyps for the proliferation marker and Phosphatidylinositol 3 kinase (p ≤ 0.0001 and 0.057 respectively). Cycloxygenase-2 and Phosphatase and tensin homolog demonstrated higher tissue immunoexpression in pedunculated polyps (p = 0.009 and 0.002 respectively). Cycloxygenase-2 exhibited higher immunoexpression in larger polyps (p = 0.005). Phosphatidylinositol 3 kinase, Cycloxygenase-2, Phosphatase and tensin homolog and the proliferation marker exhibited higher immunoexpression in high-grade dysplastic polyps (p = 0.031, 0.013, 0.044 and <0.001 respectively). Phosphatase and tensin homolog labeling was higher in polyps with high-grade dysplasia and lower in some of serrated lesions (p = 0.044).
Conclusions:
The greater expression of the proliferation marker and Phosphatidylinositol 3 kinase in the right colon may be related to right-sided colorectal carcinogenesis. The proliferation marker, Cycloxygenase-2 and Phosphatidylinositol 3 kinase results can be associated with progression of polyps to colorectal cancer. The higher Phosphatase and tensin homolog expression suggests its attempt to control the cell cycle.
Keywords:
PI3K; COX2; Colorectal cancer; Adenoma
