NCIt definition : Invasive cancer confined to the original anatomic site of growth without lymph node
involvement. The definition of stage IA depends on the particular type of cancer that
it refers to; for example, for breast cancer, stage IA is defined as follows: T1,
N0, M0. T1: Tumor 20 mm or less in greatest dimension. T1 includes T1mi. T1mi: Tumor
1 mm or less in greatest dimension. N0: No regional lymph node metastasis. M0: No
clinical or radiographic evidence of distant metastasis. M0 includes M0(i ); for bone
cancer, stage IA is defined as follows: T1, N0, M0, G1, GX. T1: Tumor 8 cm or less
in greatest dimension. N0: No regional lymph node metastasis. M0: No distant metastasis.
G1: Well differentiated-low grade. GX: Grade cannot be assessed. (partially adapted
from AJCC 8th ed.);