BACKGROUND: Colon adenocarcinoma is the second cause of cancer death in men and women, responsible for more than five million deaths each year. At the diagnosis, only 70% of tumors are resectable, 75% curative and 25% might have disease recurrence. Apoptosis is responsible for homeostatic equilibrium among cells. During the development of the cellular malignant degeneration, an abnormal apoptosis plays an important role in the neoplasm transformation. Caspase-3 is one of the most important molecules in apoptosis, considered as the principal executioner. Caspase-3 expression and its prognosis have been mentioned in a variety of study and revision as its role being emphasized since the onset of polyp formation until the malignant transformation, as apoptosis declines progressively. AIM: To evaluate the computerized image cytophotometric expression of Caspase-3 in colon adenocarcinoma; to evaluate in the respective phases of Dukes-modified Classification and to compare its expression on right-sided and left-sided colon tumors. METHODS: Nineteen recovery of sampled-tissue in paraffin blocks confirmed by hematoxylin-eosin and submitted to immunohistochemistry estreptavidin-biotin method using antibody polyclonal anti-caspase-3. Following this process, marked slides were submitted SAMBA reading using software IMUNNO 4.00. Three indexes were analyzed: label index, heterogeneity and optical density. Individual labeling, marker expression evaluation and predefined tumors groups under Dukes Classification and side of tumor occurrence were considered. RESULTS: The average labeling index for caspase-3 was 85,24, where as for optical density was 39,55 pixels. According to Dukes Classification, 12 type B presented labeling index of 86,20 and optical density of 37,72 and for 7 samples type C labeling index corresponded to 85,66 and optical density equals to 42,71, unable to identify the difference regarding to Dukes Classification. Regarding to the side of tumor occurrence, 11 left-sided tumors had labeling index of 86,65 and optical density of 43,29 and the 8 right-sided tumors had labeling index of 83,29 and optical density of 39,44, unable to observe significant statistical difference. CONCLUSION: Caspase-3 presents a distinct value expression, revealing as useful marker in colon adenocarcinoma study and its proapoptotic phase at the tumorigenesis due to its high labeling index and optical density. Regarding to Dukes Classification there was no difference between types B and C, as well as right and left sided-related colon tumor occurrence.
Colon adenocarcinoma; Tumoral marker Caspase-3; Immunohistochemistry
