Breast cancer N stages
Stage
Criterion
N0
No regional lymph node metastases
N1
Metastases in movable ipsilateral Level I or II lymph
nodes
N2a
N2b
-
Clinically fixed ipsilateral Level I or II LN
-
Clinical (incl. imaging) evidence of internal mammary
LN in absence of clinically detected axillary lymph
nodes
N3a
N3b
N3c
-
Metastases in infraclavicular LN
-
Metastases in internal mammary AND axillary lymph
nodes
-
Metastases in supraclavicular LN