Proliferation and estrogen signaling can distinguish patients at risk for early versus late relapse among estrogen receptor positive breast cancers

Table 1 Summary of patient and tumor characteristics

	Tamoxifen cohort 1		Untreated			Low MKS				High MKS					Tamoxifen
	Tamoxifen cohort 1		Untreated			High ERS		Low ERS		High ERS		Low ERS			cohort 2
Characteristic	N	%	N	%	P ^a	N	%	N	%	N	%	N	%	P ^b	N	%
Patients	683		559			373		248		248		373			282
Age, years
≤50	43	6.3	240	42.9	<0.0001	82	22.0	47	19.0	57	23.0	96	25.7	0.247	8	2.8
>50	498	72.9	306	54.8		240	64.3	172	69.3	160	64.5	233	62.5		176	62.4
Unknown	142	20.8	13	2.3		51	13.7	29	11.7	31	12.5	44	11.8		98	34.8
Tumor (T) stage
T1	214	31.3	199	35.6	<0.0001	145	38.9	102	41.1	74	29.8	92	24.7	0.003	109	38.7
T2/T3	293	42.9	140	25.0		126	33.8	82	33.1	84	33.9	141	37.8		168	59.5
Unknown	176	25.8	220	39.4		102	27.3	64	25.8	90	36.3	140	37.5		5	1.8
Nodal status
Negative	403	59.0	559	100.0	<0.0001	295	79.1	192	77.4	191	77.0	284	76.1	0.962	147	52.1
Positive	258	37.8	0	0.0		76	20.4	50	20.2	52	21.0	80	21.5		111	39.4
Unknown	22	3.2	0	0.0		2	0.5	6	2.4	5	2.0	9	2.4		24	8.5
Grade
1	108	15.8	66	11.8	0.0002	86	23.1	54	21.8	18	7.3	16	4.3	<0.0001	26	9.2
2	258	37.8	242	43.3		159	42.6	105	42.3	108	43.5	128	34.3		114	40.4
3	111	16.3	152	27.2		29	7.8	32	12.9	63	25.4	139	37.3		44	15.6
Unknown	206	30.2	99	17.7		99	26.5	57	23.0	59	23.8	90	24.1		98	34.8
HER2 by gene ^c
HER2-positive	27	4.0	44	7.9	0.169	1	0.3	8	3.2	7	2.8	55	14.8	<0.0001	-	0.0
HER2-negative	647	94.7	515	92.1		371	99.4	239	96.4	239	96.4	313	83.9		-	0.0
Unknown	9	1.3	0	0.0		1	0.3	1	0.4	2	0.8	5	1.3		282	100.0
Distant events, time cohorts
0 to 10 yrs	137		144		-	42		37		65		137		-	64
0 to 2.5 yrs	46		55			8		9		17		67			26
2.5 to 5 yrs	48		55			19		10		21		53			20
>5 yrs	43		34			15		19		26		17			18
Unknown	10		6			2		6		3		5			-

^aOnly patients with known clinical information were considered for comparison between tamoxifen-treated (cohort 1) and untreated patients. ^bOnly patients with known clinical information were considered for comparison among the four molecular groups. P-values in boldface were statistically significant at P <0.05. These molecular groups referred to the tamoxifen-treated (cohort 1) and untreated patients. ^cHER2 status was defined according to Haibe-Kains et al. [21]. N, number of patients; MKS, mitotic kinase score; ERS, estrogen-related score; HER2: human epidermal growth factor receptor 2.

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