Stage I includes: IA: T1, N0, M0 and IB: (T0, N1mi, M0); (T1, N1mi, M0). T1: Tumor 20 mm or less in greatest dimension. T1 includes T1mi. T1mi: Tumor 1 mm or less in greatest dimension. T0: No evidence of primary tumor. N0: No regional lymph node metastasis. N1mi: Nodal micrometastases. M0: No clinical or radiographic evidence of distant metastasis. M0 includes M0(i+). (AJCC 7th Ed.) [from NCI]