The Expression Of Mucin MUC1 And MUC2 In Colorectal Cancer And Its Relationship With Micrometastasis In Regional Lymph Nodes

Objective To determine the expression and clinical significance of mucin MUC1 and MUC2 in colorectal cancer with regional lymph nodes, and to investigate its relationship with lymph node micrometastasis and the impact of lymph node micrometastasis on prognosis. Methods Mucin MUC1 and MUC2 was detected in colorectal cancer with regional lymph nodes by immunohistochemistry and nested RT-PCR, and follow up was to analyze the survival rate. Results The positive expression rate of mucin MUC1 vs. MUC2 was 13.3%(2/15) vs. 100.0%(15/15) in normal colorectal mucosa, 43.4%(23/53) vs. 50.9%(27/53) in colorectal cancer, 100.0%(42/42) vs.100.0%(42/42) in metastatic lymph nodes and 21.5%(37/172) vs. 13.4%(23/172) in non-metastatic lymph nodes by IHC. The positive expression rate of mucin MUC1 mRNA vs. MUC2 mRNA was 100.0% vs. 100.0% in colorectal cancer and metastatic lymph nodes, 39.5%(68/172) vs. 37.8%(65/172) in non-metastatic lymph nodes by nested RT-PCR. Lymph nodes micrometastasis rate increased significantly with Dukes upstage, and 9 patients with colorectal cancer upstaged from Dukes A or B to Dukes C. Follow up shown that recurrence and metastasis rate of colorectal cancer patients with lymph nodes micrometastasis was significantly higher than that of the colorectal cancer patients without lymph nodes micrometastasis. Conclusions The up-regulation of mucin MUC1 expression and/or down-regulation of mucin MUC2 expression may be involved in carcinogenesis and progression in colorectal cancer, and both were reliable indicator for detection of lymph node micrometastasis, which may provide more accurate stage for colorectal cancer. Higher recurrence and metastatic rate and poorer prognosis were found in colorectal cancer patients with lymph nodes micrometastasis.