KL-6 mucin in metastatic liver cancer tissues from primary colorectal carcinoma.

KL-6 mucin is MUC1 bearing sialylated carbohydrate epitopes recognized by KL-6 antibody. This study aimed to assess subcellular localization of KL-6 mucin in liver metastatic tissues from colorectal carcinoma and hepatocellular carcinoma tissues.Tissue samples were collected from 56 patients with liver metastasis of colorectal carcinoma and 92 patients with hepatocellular carcinoma who underwent a hepatectomy. Tissues were subjected to immunohistochemical analysis using KL-6 antibody.All 56 cases with metastatic liver cancer showed positive staining for KL-6 mucin in cancer tissues but not in non-cancerous tissues. All staining was observed in the circumferential membrane and/or cytoplasm of the cancer cells. In contrast, no staining for KL-6 mucin was observed in either cancerous or non-cancerous tissues of the 92 patients with hepatocellular carcinoma.KL-6 mucin may be an indicator for liver metastasis of colorectal carcinoma. Additionally, detection of KL-6 mucin may be helpful in distinguishing hepatocellular carcinoma from metastatic liver cancer.