Stage IV includes: IVA: T4, N0-1, M0; IVB: (Any T, N2, M0); (Any T, Any N, M1). T4: Tumor invading the main portal vein or hepatic artery or invading two or more extrahepatic organs or structures. N0: No regional lymph node metastasis. N1: Metastases to one to three regional lymph nodes. N2: Metastases to four or more regional lymph nodes. M0: No distant metastasis. M1: Distant metastasis. (AJCC 8th ed.) [from NCI]