1, NX: Regional LNs cannot be assessed \n 2, N0: No regional LNs metastasis \n 3, N1: Movable ipsilateral axillary LN(s) \n 4, N2: Ipsilateral axillary LN(s) fixed \n 5, N3: Ipsilateral internal mammary LN(s) \n 6, pNX: Regional LNs cannot be assessed \n 7, pN0: No regional LNs metastasis \n 8, pN1: movable ipsilateral axillary LN(s) \n 9, pN1a:Only micrometastasis <=0.2 cm \n 10, pN1b: Metastasis any >0.2 cm \n 11, pN1bi:1 to 3 LNs, any >0.2 cm and all <2.0 cm \n 12, pN1bii: >=4 LN3, any >0.2 cm and all <2.0 cm \n 13, pN1biii: beyond LN capsule,metastasis <2.0 cm \n 14, pN1biv: Metastasis to a LN >=2.0 cm \n 15, pN2: to ipsilateral axillaryLN(s) fixed \n 16, pN3: to ipsilateral internal mammary LN(s) \n 17, pN0(i+)