Expression of metallothionein in colorectal cancers and synchronous liver metastases

The aim of this study is to clarify whether the expression of metallothione in (MT) is related with the malignant potential in primary colorectal cance r and/or synchronous liver metastasis. Immunohistochemical staining for MT was performed on the specimens of adenocarcinoma of the colon and rectum an d its liver metastases in 34 patients treated with curative surgery, respec tively. Expression of MT was compared with clinicopathological variables an d patient survival. In patients with primary colorectal cancer, positive ex pression was found in 7 of 34 (20.6%) patients, but MT was not detected in any of the cases of liver metastases (0%; p = 0.0111). In the primary tumor , positive MT expression was significantly associated with a higher degree of lymph node involvement (mean +/- SD: 48.4 +/- 33.8 vs. 18.6 +/- 24.4% in MT-positive and MT-negative tumors, respectively; p = 0.0122). The surviva l rate in the patients with MT-negative tumors was significantly better tha n that in those with MT-positive tumors as primary sites (p = 0.0198). MT e xpression in colorectal cancer may be a potential marker affecting lymph no de metastases and may be a predictor of a poor prognosis, particularly in p atients with synchronous liver metastases. Copyright (C) 2001 S. Karger AG, Basel.