Stage I includes: IA (T1, N0, M0, G1, G2, GX); IB (T2, N0, M0, G1, G2, GX); (T3, N0, M0, G1, G2, GX). T1: Tumor 8 cm or less in greatest dimension. T2: Tumor more than 8 cm in greatest dimension. T3: Discontinuous tumors in the primary bone site. N0: No regional lymph node metastasis. M0: No distant metastasis. G1: Well differentiated-low grade. G2: Moderately differentiated-low grade. GX: Grade cannot be assessed. (AJCC 7th ed.) [from NCI]