Stage IV includes: IVA: (Any T, Any N, M1a); IVB: (Any T, Any N, M1b). M1a: Metastasis confined to one organ or site (e.g., liver, lung, ovary, nonregional node). M1b: Metastases in more than one organ/site or the peritoneum. (AJCC 7th ed.) [from NCI]