Background/aims: Predicting the lymph node metastatic or distant metastatic potential of T1 adenocarcinoma of the colon and rectum remains a major challenge. We investigated the role of the expressions of tumor matrilysin (MMP-7), VEGF-C and VEGF-A in predicting these metastatic potentials.
Methodology: Single T1 adenocarcinomas were examined and pathological tumor factors were reviewed. Immunohistochemical staining of VEGF and MMP-7 was performed and the metastatic potential was defined on the basis of the presence of lymph nodes in the specimen or the identification of other distant metastasis during follow-up examinations.
Results: There was little correlation between the IHC staining results of VEGF-A, VEGF-C and MMP-7 in the same specimen (kappa<0.1). After a 61-month median follow-up (2-131 months), 17 (11.8%) tumors showed metastatic potential, including 14 lymph node metastases and 3 distant metastases. The tumors showing high levels of MMP-7 expression had higher metastatic potentials than those with low expression (19.1% vs. 8.2%, respectively; p=0.057). Overexpression of MMP-7 generally indicated an inferior overall survival (p=0.09). In analysis of the traditional pathological tumor factors, only lymphovascular invasion showed significance in predicting metastatic potential (p=0.04).
Conclusions: Overexpression of MMP-7 generally indicated a higher metastatic potential and inferior overall survival. Lymphovascular invasion was a significant risk factor for lymph node metastasis.