Table 4. Upstaging rates in the permanent histology cohort according to the 7th American Joint Committee on Cancer Staging System.

		Overall axillary stage
		pN1mi		pN1a		pN2a		pN3a
Sentinel lymph- node stage	No.	No.	%	No.	%	No.	%	No.	%	Upstaging rate (%)
pN1mi (sn)	21	19	90.5	1	4.8	1	4.8	0	0	9.5
pN1a (sn)	41	—	—	34	82.9	4	9.8	3	7.3	17.1
pN2a (sn)	2	—	—	—	—	2	100	0	0	0
All	64	19	29.7	35	54.7	7	10.9	3	4.7	14.1