Stage IV includes: (T4, N0, M0); (T4, N1, M0); (Any T, N2, M0), (Any T, Any N, M1). T4: Tumor invades other adjacent organs. N0: No regional lymph node metastasis. N1: Metastasis in a single lymph node 2 cm or less in greatest dimension. N2: Metastasis in a single lymph node more than 2 cm in greatest dimension, or in multiple lymph nodes. M0: No distant metastasis. M1: Distant metastasis. (AJCC 7th ed.) [from
NCI]