1. From the International Cooperative Study Group on Hepatocellular Carcinoma; Departments of Surgical Oncology, Biostatistics and Biomathematics, and Pathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX; Department of Pathology, Massachusetts General Hospital, Boston, MA; Department of General Surgery, Mayo Clinic, Rochester, MN; and Department of Surgery, Hôpital Beaujon, Paris, France.