Table 1.

Comparison of patient characteristics according to data availability (N = 430 v 4294)

	Available IHC-4 markers
	Yes (N = 430)		No (N = 4294)
	N	%	N	%
Treatment
Tamoxifen	208	48.4	2164	50.4
Exemestane	222	51.6	2130	49.6
Age (years)
< 60	142	33.0	1381	32.2
60–69	191	44.4	1830	42.6
70 +	97	22.6	1083	25.2
Grade
GI	97	22.6	692	16.1
GII	209	48.6	1778	41.4
GIII	78	18.1	845	19.7
Not assessable	2	0.5	101	2.4
Unknown	44	10.2	878	20.4
Nodes
Negative	193	44.9	2254	52.5
1–3 N+	143	33.3	1288	30.0
>3 N+	59	13.7	599	13.9
Unavailable	35	8.1	153	3.6
Tumour size (cm)
≤ 2	246	57.2	2539	59.1
>2 & ≤ 5	168	39.1	1548	36.1
>5	13	3.0	109	2.5
Unavailable	3	0.7	98	2.3
Histology type
Infiltrating ductal	329	76.5	3278	76.3
Infiltrating lobular	53	12.3	609	14.2
Other	48	11.2	398	9.3
Unavailable	0	0	9	0.2
Previous chemotherapy use
Yes	76	17.7	1466	34.1
No	354	82.3	2828	65.9
HRT use
Yes	145	33.7	979	22.8
No	276	64.2	3211	74.8
Unavailable	9	2.1	104	2.4