Table A1.

Clinical Characteristics of Patients in the Four Risk Groups Predefined by Nomogram-Predicted Risks

Characteristic	Group 1: IBTR < 3%		Group 2: IBTR 3%-5%		Group 3: IBTR 5%-10%		Group 4: IBTR > 10%
	No.	%	No.	%	No.	%	No.	%
No. of patients	283		237		111		33
Median age, years	63.5		58.1		47.6		37.9
≤ 40	0	0	3	6	23	46	24	48
41-45	0	0	11	25	29	66	4	9
46-50	42	44	43	45	10	10	1	1
51-55	30	32	39	41	24	26	1	1
56-60	47	52	33	37	10	11	0	0
61-65	31	48	29	45	4	6	1	2
66-70	42	45	45	48	5	5	2	2
> 70	91	69	34	26	6	5	0	0
Margin
Positive	2	4	14	27	26	50	10	19
Close (< 2 mm)	41	58	18	25	9	13	3	4
Negative (> 2 mm)	240	44	205	38	76	14	20	4
Unknown	0		0		0		0
Lymphovascular invasion
Present	44	37	35	30	33	28	6	5
Absent	239	44	202	37	78	14	27	5
Unknown	0		0		0		0
Tumor size, cm
≤ 1	78	30	123	47	48	18	14	5
1.1-2	158	56	78	28	35	12	9	3
> 2	47	39	36	30	28	23	10	8
Grade
I	112	74	31	20	9	6	0	0
II	151	46	127	38	46	14	7	2
III	20	11	79	44	56	31	26	14
Unknown	0		0		0		0
Hormone therapy
Yes	235	58	118	29	47	12	4	1
No	48	18	119	46	64	25	29	11
Chemotherapy
Yes	82	37	67	31	51	23	19	9
No	201	45	170	38	60	13	14	3

Abbreviation: IBTR, ipsilateral breast cancer tumor recurrence.