Nowadays neoplastic and nonneoplastic colonic lesions represent a existing danger in Egypt, where the incidence rate is continuously progressing, and are more commonly seen in the younger age group. Hypothesis is to study role of K-Ras oncogene and Fas receptor protein in colonic lesions among Egyptians and their impact on grades and stages of colorectal carcinoma (CRC).
Patients and methods
This study enrolled 85 cases: control 10, ulcerative colitis (UC) with and without dysplasia 3 and 7, respectively, Crohn’s disease (CD) 10, bilharzial colitis 15, and CRC 40. Immunohistochemical staining for K-Ras and Fas monoclonal antibodies was done.
K-Ras was negative in control. UC with and without dysplasia, CD and bilharzial colitis showed positivity for K-Ras relative to CRC (P<0.05). CRC showed a positive correlation between the extent of expression of K-Ras and both the disease grades and the Dukes stages of CRC. Seventy percent of control were positive for Fas relative to CRC (P<0.01). UC with and without dysplasia, CD, and bilharzial colitis showed positivity for Fas relative to CRC (P<0.01). CRC showed a significant inverse correlation between the extent of positive expression of Fas and both disease grades and the Dukes/ stages of CRC.
We concluded that CRC showed the most intense K-Ras expression suggesting that it is playing an important role in disease progression. K-Ras mutation was not intensely expressed in UC and CD with dysplasia suggesting that it is not the only factor involved in progression to neoplasia. CRC expresses significant lower levels of Fas relative to other studied groups.
This supports the idea of the ability of neoplastic cells to escape the host immune system by avoiding apoptosis and thus can progress to more advanced stages.