Immunoexpression of Matrix Metalloproteinase-9 in Colorectal Adenocarcinoma

Colorectal carcinoma is one of the most common malignant tumors of gastrointestinal tract and is a contributing factor of cancer mortality in Myanmar. Matrix metalloproteinase-9 is a proteolytic enzyme which breaks down extracellular matrix leading to tumor progression, contri-buting as a potential prognostic marker nowadays. The study was aimed to determine MMP-9 immunoexpression in colorectal adenocarcinoma and its association with Astler-Coller staging. A cross-sectional descrip-tive study was done on 42 specimens of colorectal adenocarcinoma. All tissue specimens were studied with haematoxylin and eosin to categorize histological types and grades. Out of 42 cases, 21.4% were well differentiated, 57.2% were moderately differentiated and 21.4% were poorly differentiated. According to Astler-Coller staging, 11.9% were found to be in stage B1, 40.5% in stage B2, 7.1% in stage C1, 33.3% in stage C2 and 7.1% in stage D. 81% (34/42) of colorectal carcinoma showed positive MMP-9 immunoexpression. Positive MMP-9 immuno-expression was seen in 91% of conventional adenocarcinoma, 40% of mucinous carcinoma and no cases signet ring carcinoma. The findings of the study pointed out that MMP-9 immunoexpression was positively associated with histological types of colorectal adenocarcinoma (p=0.001). MMP-9 immunoexpression was positive in 88.9% of well differentiated adenocarcinoma, 91.7% of moderately differentiated adenocarcinoma and 44.4% of poorly-differentiated adenocarcinoma (p=0.007). Regarding the immunoexpression of MMP-9 in different Astler-Coller staging, positive MMP-9 immunoexpression was seen in 60% of the cases in stage B1, 76.5% in stage B2, 66.7% in stage C1, 92.9% in stage C2 and 100% in stage D. The findings of the study can be extrapolated to predict prognosis and help in better management of colorectal adenocarcinoma by introducing targeted therapy against MMP-9 in future.