Macroscopic intrabiliary growth of liver metastases from colorectal cancer

BACKGROUND: The clinicopathologic features of colorectal liver metastases that invade the bile duct were evaluated. METHODS: From 1992 to 1996, 149 patients who underwent a first hepatic resection were studied for a total of 377 colorectal liver metastases. Twenty-one second hepatic resections in these patients were also analyzed. RESULTS: Bile duct invasion was histologically observed in 62 (42%) of 149 patients with first colorectal liver metastasis. Eighteen patients (12%) had gross extension of the tumor in the bile duct ranging from 4 mm to 42 mm (median 17.0 mm). Histologically, two thirds (12 of 18) of the tumors with macroscopic bile duct invasion were well-differentiated adenocarcinomas with a tendency for less vascular involvement. The actuarial 3- and 5-year survivals were 62% and 57% for patients with no bile duct invasion, 56% and 48% for patients with microscopic bile duct invasion, and 94% and 80% for patients with macroscopic bile duct invasion. The 5-year survival rate was better for patients with macroscopic bile duct invasion than for those with only microscopic (P = .02) or no bile duct invasion (P = .03). In a multivariate analysis, macroscopic bile duct invasion was an independent prognostic variable for favorable outcome after hepatic resection. CONCLUSIONS: Macroscopic bile duct invasion of colorectal liver metastases may reflect an indolent biologic behavior, warrants an aggressive surgical approach, and confers a better prognosis.