Table 5.

Axillary Lymph Node Variables Stratified by Tumor Size, According to Breast Tumor Subtype

	Basal-like	Luminal A	Luminal B	HER2+/ER−	Unclassified
	n=199	n=608	n=111	n=69	n=132
Lymph Node Status (Percent Positive Tumors, n)
≤2 cm	30%,70	19%, 329	35%, 57	23%, 22	21%, 63
>2–5 cm	41%, 106	54%, 228	61%, 44	59%, 37	47%, 51
>5 cm	57%, 21	79%, 48	86%, 7	100%, 10	56%, 18
P-value*	0.07	<0.0001	0.004	0.0002	0.002
Number of Positive Lymph Nodes (Mean, Median)
≤2 cm	1.4, 0	0.7, 0	1.4, 0	0.5, 0	1.3, 0
>2–5 cm	1.8, 0	2.2, 1.0	3.1, 1.0	3.2, 1.0	2.5, 0
>5 cm	4.0, 1.0	5.4, 2.0	7.6, 4.0	6.3, 6.0	4.1, 1.0
P-value†	0.04	<0.0001	0.001	< 0.0001	0.002
Percent Positive Lymph Nodes (Mean, Median)
≤2 cm	13%, 0	5%, 0	13%, 0	5%, 0	10%, 0
>2–5 cm	14%, 0	19%, 7%	19%, 10%	19%, 11%	22%, 4%
>5 cm	24%, 8%	34%, 18%	46%, 54%	47%, 42%	29%, 7%
P-value†	0.17	<0.0001	0.005	<0.0001	0.007

^*Chi-square test (percentages) comparing categories of tumor size

^†Wilcoxon rank sum test (medians) comparing categories of tumor size