For hepatocellular carcinoma: Stage I includes: T1, N0, M0. T1: Solitary tumor without vascular invasion. N0: No regional lymph node metastasis. M0: No distant metastasis. For intrahepatic cholangiocarcinoma: Stage I includes: T1, N0, M0. T1: Solitary tumor without vascular invasion. N0: No regional lymph node metastasis. M0: No distant metastasis. (from AJCC 7th Ed.) [from NCI]