Impact of histological grade of hepatocellular carcinoma on the outcome of liver transplantation

Hypothesis: Histological grade of hepatocellular carcinoma (HCC) is an important prognostic factor affecting patient survival after orthotopic liver transplantation (OLT). Design: Retrospective analysis. Setting: University-based teaching hospital. Patients: Of 952 OLTs performed between June 1991 and January 1999, 56 OLT recipients had histologically proven HCC in the explant liver. Of those, 53 patients with complete clinicopathologic data were analyzed. A single pathologist blinded to the outcome of each patient reviewed all histological specimens. Results: Median follow-up was 709 days. Overall survival for patients with tumors sized 5 cm or less at 1, 3, and 5 years was 87%, 78%, and 71%, respectively (Kaplan-Meier). Univariate analysis revealed the size, number, and distribution of tumors; the presence of microscopic vascular invasion and lymph node metastasis; histological differentiation; and pTNM stage to be statistically significant factors affecting survival. Multivariate analysis revealed histological differentiation and pTNM stage to be the independent and statistically significant factors affecting survival (P = .002 and .03, respectively). When pTNM stage was excluded from multivariate analysis, histological differentiation and size remained the significant independent factors (P = .02 and .03, respectively). Three-year survival for patients with small (less than or equal to5 cm) tumor with well- to moderately differentiated and poorly differentiated HCC was 82% and 67%, respectively. Three-year survival for patients with large (>5 cm) tumor with well- to moderately differentiated and poorly differentiated HCC was 62.5% and 0%, respectively. Conclusions: In our retrospective experience, histological differentiation had a statistically significant effect on the prognosis of HCC after OLT. However, before altering the current OLT selection criteria for patients with HCC, prospective studies are required to confirm the impact of histological grade on clinical outcome.