Table 1.

Patient and tumour characteristics

	Index cohort		Validation cohort		P		Index cohort		Validation cohort		P
	(2003–2006)		(2007–2008)				(2003–2006)		(2007–2008)
	n	%	n	%			n	%	n	%
Total	37,278		12,318			PR status					0.004
Age category					<0.001	Negative	9580	33.7	3806	32.2
<50	9779	26.2	3006	24.4		Positive	18,877	66.3	8018	67.8
50–59	10,601	28.4	3353	27.2		Unknown	8821		494
60–69	8421	22.6	3101	25.2		Her2-Neu status					0.017
≥70	8477	22.7	2858	23.2		Negative	13,832	85.2	10,238	86.2
Histologic type					0.300	Positive	2405	14.8	1639	13.8
Ductal	29,582	79.4	9795	79.5		Unknown	21,041		441
Lobular	4000	10.7	1271	10.3		Number of surgeries					0.383
Mixed	1552	4.2	551	4.5		1	33,136	88.9	10,926	88.7
Other	2144	5.8	701	5.7		2	3909	10.5	1301	10.6
Grade					<0.001	≥3	233	0.6	91	0.7
I	7628	22.0	2907	24.5		Type of surgery					<0.001
II	15,595	44.9	5253	44.3		Breast conserving	21,049	56.5	7215	58.6
III	11,479	33.1	3700	31.2		Non-breast conserving	16,229	43.5	5103	41.4
Unknown	2576		458			Time from indicence to last OK					0.720
Tumour size					<0.001
≤2 cm	22,611	61.2	7796	63.7		<30 days	27,579	74.0	9098	73.9
2-5 cm	13,243	35.8	4152	33.9		30–60 days	8205	22.0	2742	22.3
>5 cm	1094	3.0	283	2.3		>60 days	1494	4.0	478	3.9
Unknown	330		87			Axillary lymph node dissection					<0.001
Multifocal					0.257
No	23,237	84.8	10,275	84.3		No	18,397	49.4	7315	59.4
Yes	4168	15.2	1907	15.7		Yes	18,881	50.6	5003	40.6
Unknown	9873		136			Chemotherapy					<0.001
Lymph node status					<0.001	No	23,886	64.1	7583	61.6
Negative	22,516	61.3	7809	64.0		Yes	13,392	35.9	4735	38.4
1–3 positive	10,093	27.5	3189	26.2		Radiotherapy					0.001
>3 positive	4119	11.2	1196	9.8		No	12,783	34.3	4026	32.7
Unknown	550		124			Yes	24,495	65.7	8292	67.3
ER status					0.001	Hormone therapy					<0.001
Negative	5417	18.8	2113	17.3		No	21,696	58.2	6563	53.3
Positive	23,433	81.2	10,066	82.7		Yes	15,582	41.8	5755	46.7
Unknown	8428		139

LRR locoregional recurrence, ER oestrogen receptor, PR progesterone receptor, Her2-Neu human epidermal growth factor receptor 2