Biliary metastasis in colorectal cancer confers a poor prognosis: case study of 5 consecutive patients

The biliary duct is an extremely rare site for colon cancer metastasis. It often leads to a diagnostic dilemma, since primary cholangiocarcinoma (potentially treatable with surgery) has a similar presentation. This paper highlights our experience with 5 consecutive patients who had colon malignancy with biliary metastasis, and prognosis of their disease. Five patients, with a history of primary colon cancer since 2010, were identified to have biliary metastasis. Of these, 4 (80.0%) patients were male. The median time to diagnosis of biliary metastasis from diagnosis of colon cancer was 59.2 months (0-70.1 months), and all exhibited symptoms of biliary obstruction or its associated complications. Evaluation of the tumour samples revealed all specimens to be negative for CK7 but positive for CK20, suggestive of a colorectal primary. The median survival of the 5 patients was 23.5 months (1.8-44.5 months) from the diagnosis of biliary metastasis. However, none of their death was related to the direct complication of biliary obstruction. Biliary metastasis is a rare entity for metastatic colon malignancy. Diagnosis may be difficult radiologically, and immunohistochemical staining may help in identification. The overall survival for these patients is dismal.