Can clinically relevant prognostic subsets of breast cancer patients with four or more involved axillary lymph nodes be identified through immunohistochemical biomarkers? A tissue microarray feasibility study

Table 1 Frequencies of conventional prognostic factors and adjuvant treatments in the test set

Factor	Division	Whole set (313 patients)		Subset (227 patients)
		n	Percentage	n	Percentage
Age	≤40	34	10.9	25	11.0
	>40	279	89.1	202	89.0
Menopausal status	Pre	104	33.2	76	33.5
	Post	203	64.9	147	64.8
	Unknown	6	1.9	4	1.8
Tumor grade	1	5	1.6	4	1.8
	2	101	32.3	71	31.3
	3	191	61.0	144	63.4
	Unknown	16	5.1	8	3.5
Tumor size, cm	0–2	100	31.9	71	31.3
	> 2–5	173	55.3	131	57.7
	> 5	35	11.2	22	9.7
	Unknown	5	1.6	3	1.3
Pathological ER status	Negative	72	23.0	54	23.8
	Positive	234	74.8	169	74.4
	Unknown	7	2.2	4	1.8
Lymphovascular invasion	Negative	49	15.7	33	14.5
	Positive	244	78.0	184	81.1
	Unknown	20	6.4	10	4.4
Percentage of positive nodes	0–50	121	38.7	89	39.2
	>50–99.9	142	45.4	95	41.9
	100	50	16.0	43	18.9
Number of positive nodes	4–9	235	75.1	175	77.1
	≥10	78	24.9	52	22.9
Histology	Ductal	279	89.1	210	92.5
	Lobular	34	10.9	17	7.5
Adjuvant chemotherapy	No	155	49.5	107	47.1
	Yes	158	50.5	120	52.9
Adjuvant hormonal therapy	No	104	33.2	78	34.4
	Yes	209	66.8	149	65.6
Adjuvant radiotherapy	No	70	22.4	50	22.0
	Yes	243	77.6	177	78.0
Mastectomy	No	2	0.6	1	0.4
	Complete	217	69.3	154	67.8
	Partial	94	30.0	72	31.7

Data are presented for the 313-patient test set cohort, and for the 227-patient subgroup in which expression data were available for each of the eight immunohistochemical biomarkers assessed. Percentages are rounded.

ISSN: 1465-542X