Assessment of CD44S and CD44V6 in colorectal carcinoma [immunohistochemical study]

ABSTRACT

The last few years showed an increase in the incidence of colorectal cancer in our country. From 20% to 50% of patients are susceptible to death within 5 years of diagnosis, usually as a result of metastasis. Tumor growth, invasion and metastasis may be enhanced by alteration in the expression of certain adhesion molecules such as CD44s and CD44 v6. In an effort to detect the difference in the immunohistochemical expression of CD44s and CD44 v6 glycoproteins in colorectal carcinomas and correlating this expression with other clinicopathological parameters, we studied 55 cases of colorectal carcinomas resected from patients who underwent surgery at Assuit university Hospital in the period from 2003 to 2004. Forty five cases were conventional adenocarcinoma and 10 cases were of mucinous carcinoma type. The mean age was [44.9 +/- 2.5] with male predominance in cases of conventional adenocarcinoma, while the mean age was [33.4 +/- 2.67] in mucinous carcinoma with female predominance. Most of the cases were of stage B with only 11 cases of stage C and no cases of stage A. Positive staining for CD44s was detected in 81.8% of cases, in contrast to 69% positive cases for CD44v6. CD44s showed statistically significant higher mean of IRS [immunoreactivity score] in mucinous carcinoma than in adenocarcinoma while the opposite was noticed for CD44v6 but without statistical significance. There was inverse relation between IRS for CD44s and tumor grade, while IRS of CD44v6 showed direct relation with the grade. CD44v6 IRS exhibited upregulation with increasing stage and statistically significant higher level in tumors with infiltrating borders. In conclusion, CD44s had a significant relation to the type of colorectal cancer as its mean of IRS increased in mucinous carcinoma than in conventional adenocarcinoma which may indicate their better prognosis. CD44v6 may be an indicator for the metastatic potential of the tumor as its expression showed upregulation with progression of the stage and grade of the tumor and increased in tumors with infiltrating border