NCIt definition : Stage IA includes: 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 ).
(AJCC 7th Ed.);
Alternative definition : NCI-GLOSS: Stage I breast cancer is divided into stages IA and IB. In stage IA, the
tumor is 2 centimeters or smaller and has not spread outside the breast.;