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.