Supplementary Table 1: Distribution of the intrinsic subtypes within HR+/HER2-negative and node-negative disease across the 3 cohorts

  

		VHIO	GEICAM 2012-09	CBM Rome	All patients
	Lum A	139 (53.1%)	108 (67.1%)	47 (50.0%)	294 (56.9%)
	Lum B	115 (43.9%)	50 (31.1%)	46 (48.9%)	211 (40.8%)
	HER2-enriched	4 (1.5%)	2 (1.2%)	0	6 (1.2%)
	Basal-like	4 (1.5%)	1 (0.6%)	1 (1.1%)	6 (1.2%)
	N	262	161	94	517
	Chi-square 12.404 p = 0.054.			

www.impactjournals. 
com/oncotarget/ Oncotarget, Supplementary Materials 2017 Supplementary Table 2: Distribution of the ROR groups within HR+/HER2-negative and node-negative disease across the 3 cohorts VHIO GEICAM 2012-09 CBM Rome All patients

  
	Low risk	91 (34.7%)	83 (51.6%)	25 (26.6%)	199 (38.5%)
	Intermediate risk	85 (32.4%)	51 (31.7%)	35 (37.2%)	171 (33.1%)
	High risk	86 (32.8%)	27 (16.8%)	34 (36.2%)	147 (28.4%)
	N	262	161	94	517
	Chi-square 23.630 p = 0.000095.			

www.impactjournals. 
com/oncotarget/ Oncotarget, Supplementary Materials 2017 Supplementary Table 3: Distribution of subtypes across each Ki67 group in 517 patients with HR+/HER2-negative node-negative disease Intrinsic subtypes

  
	Supplementary				
		Luminal A	Luminal B	HER2-enriched	Basal-like
	Ki67 group				
	0-10%	193 (65.6%)	42 (19.9%)	2 (33.3%)	0
	11-20%	63 (21.4%)	59 (28.0%)	0	0
	21-30%	29 (9.9%)	69 (32.7%)	1 (16.7%)	0
	>30%	9 (3.1)	41 (19.4%)	3 (50%)	6 (100%)
	Total	294	211	6	6

Table 4 : Distribution of ROR across each Ki67 group in 517 patients with HR+/HER2-negative node-negative disease

 4 
			ROR and T≤2cm	
		ROR-Low	ROR-Med	ROR-High
	Ki67 group			
	0-10%	102 (70.3%)	52 (40.3%)	24 (19.0%)
	11-20%	28 (19.3%)	44 (34.1%)	25 (19.8%)
	21-30%	12 (8.3%)	25 (19.4%)	42 (33.3%)
	>30%	3 (2.1%)	8 (6.2%)	35 (27.8%)
	Total	145	129	126
			ROR and T>2cm	
		ROR-Low	ROR-Med	ROR-High
	Ki67 group			
	0-10%	39 (72.2%)	17 (40.5%)	3 (14.2%)
	11-20%	6 (11.1%)	13 (31.0%)	6 (28.6%)
	21-30%	4 (9.3%)	9 (21.4%)	6 (28.6%)
	>30%	4 (7.4%)	3 (7.1%)	6 (28.6%)
	Total	54	42	21

com/oncotarget/ Oncotarget, Supplementary Materials 2017 Supplementary Table 5: Distribution of subtypes and ROR within each Ki67 group in 255 patients with HR+/HER2- negative node-negative disease (GEICAM 2012-09 and CBM-Rome cohorts)

  
			Ki67 Group		
		0-10%	11-20%	21-30%	>30%
	Intrinsic Subtypes				
	Luminal A	114 (81.4%)	28 (56%)	9 (25.7%)	4 (13.3%)
	Luminal B	25 (17.9%)	22 (44%)	26 (74.3%)	23 (76.7%)
	HER2-enriched	1 (0.7%)	0	0	1 (3.3%)
	Basal like	0	0	0	2 (6.7%)
	Total	140	50	35	30
	ROR and T≤2cm				
	ROR-Low	61 (59.8%)	12 (26.1%)	4 (12.9%)	1 (4%)
	ROR-Med	30 (29.4%)	22 (47.8%)	12 (38.7%)	4 (16%)
	ROR High	11 (10.8%)	12 (26.1%)	15 (48.4%)	20 (80%)
	Total	102	46	31	25
	ROR and T>2cm				
	ROR-Low	26 (68.4%)	0	2 (50%)	2 (40%)
	ROR-Med	12 (31, 6%)	3 (75%)	2 (50%)	1 (20%)
	ROR-High	0	1 (25.0%)	0	2 (40%)
	Total	38	4	4	5