Correlation between expression of MMP-7 in gastric submucosal invasive carcinoma and lymph node micrometastasis

To clarify the mechanism of tumor metastasis, lymph nodes micrometastasis and expression of MMP-7, which is related to lymph node metastases, were investigated in 45 submucosal, invasive gastric carcinomas. Metastases to lymph nodes were detected in 12 of 45 cases(26.7%) by HE stain. In 13 of 45 cases (28.9%), only micrometastases were detected by immunostaining with anti-cytokeratin antibody. The incidence of micrometastases was higher in poorly-differentiated carcinoma than well-differentiated carcinoma. Expression of MMP-7 was higher in metastasis positive cases than in negative cases. In poorly-differentiated cases, expression of MMP-7 was associated with micrometastasis. In conclusion, expression of MMP-7 may play an important role not only in tumor metastasis but in micrometastasis to lymph node especially in poorly-differentiated cases.