Stage I includes: T1, N0, M0. T1: Tumor 2 cm or less in greatest dimension with less than two high-risk features. High-risk features for the primary tumor staging are defined as follows: depth/invasion of more than 2 mm thickness, Clark level equal or greater than IV, and perineural invasion. Anatomic location: primary site ear and primary site non-hair-bearing lip. Differentiation: poorly differentiated or undifferentiated. N0: No regional lymph node metastasis. M0: No clinical or radiographic evidence of distant metastasis. (AJCC 7th ed.) [from NCI]