Table 1.

Patient characteristics^a

	Patients’ age at onset
	<35 (n = 736)		35–50 (n = 6905)		50– (n = 17,661)
	N	%	N	%	N	%	P value
T stage
Tis	73	9.9	795	11.5	1580	9.0	<.001
T0	5	0.7	97	1.4	233	1.3
T1	229	31.1	2655	38.5	6870	38.9
T2	301	40.9	2434	35.3	6475	36.7
T3	93	12.6	579	8.4	1243	7.0
T4	26	3.5	280	4.1	1109	6.3
Unk	9	1.2	65	0.9	151	0.9
Nodal status
Negative	515	70.0	5281	76.5	13,625	77.2	<.001
Positive	210	28.5	1547	22.4	3825	21.7
Unk	11	1.5	77	1.1	211	1.2
M
M0	692	94.0	6640	96.2	16848	95.4	<.001
M1	29	3.9	128	1.9	461	2.6
Unknown	15	2.0	137	2.0	352	2.0
Stage
0	73	9.9	795	11.5	1576	8.9	<.001
1	202	27.5	2468	35.7	6354	36.0
2	338	45.9	2886	41.8	7499	42.5
3	78	10.6	535	7.8	1511	8.6
4	29	3.9	128	1.9	461	2.6
Unknown	16	2.2	93	1.4	260	1.5
ER
Negative	195	26.5	1307	18.9	4578	25.9	<.001
Positive	517	70.2	5353	77.5	12544	71.0
Unknown	24	3.3	245	3.6	539	3.1
PR
Negative	263	335.7	1647	23.9	7594	43.0	<.001
Positive	447	60.7	4997	72.4	9460	53.6
Unknown	26	3.5	261	3.8	607	3.4
HER2
Negative	554	75.3	5231	75.8	12961	73.4	<.001
Positive	101	13.7	806	11.7	2582	14.6
Unknown	81	11.0	868	12.9	2118	12.0
Surgery
None	1	0.1	4	0.1	18	0.1	<.001
BCT	456	62.0	4070	58.9	9092	51.5
Mastectomy	256	34.8	2671	38.7	8115	45.9
Others	16	2.2	97	1.4	217	1.2
Unknown	7	1.0	63	0.9	219	1.2
Adjuvant therapy
None	126	17.1	1036	15.0	3414	19.3	<.001
ET	252	34.2	2899	42.0	7725	43.7
ET + CT	197	26.8	1834	26.6	3133	17.7
CT	122	16.6	879	12.7	2701	15.3
Unknown	39	5.3	257	3.7	688	3.9

Bold P value <0.05

^aTNM classification is shown based on the sixth edition of the Unio Internationalis Contra Cancrum staging system; ER estrogen receptor, PR progesteron receptor, HER2 human epidermal growth factorreceptor 2, BCT breast conserving therapy, ET endocrine therapy, CT Chemo therapy