Table 1.

Clinical and pathologic characteristics of entire population and by receipt of radiation

Characteristic		Entire population (N=2996)		No radiation (N=1374)a		Radiation (N=1588)a
		N	%	N	%	N	%
Age	≤50 years	845	28.2%	350	25.5%	486	30.6%
	>50 years	2151	71.8%	1024	74.5%	1102	69.4%
Menopausal status	Pre/peri	1038	34.6%	442	32.1%	586	36.9%
	Post	1946	65.0%	924	67.2%	999	62.9%
	Unknown	12	0.4%	8	0.6%	3	0.2%
Family history	No	1816	60.6%	825	60.0%	969	61.0%
	Yes	1136	37.9%	515	37.5%	610	38.4%
	Unknown	44	1.5%	34	2.5%	9	0.6%
Presentation	Clinical	386	12.9%	195	14.2%	178	11.2%
	Radiologic	2606	87.0%	1176	85.6%	1409	88.7%
	Unknown	4	0.1%	3	0.2%	1	<0.1%
Nuclear grade	Low/intermediate	1787	59.6%	975	71.0%	799	50.3%
	High	994	33.2%	269	19.6%	716	45.1%
	Unknown	215	7.2%	130	9.5%	73	4.6%
Number of excisions	1	1493	49.8%	800	58.2%	676	42.6%
	2	1282	42.8%	525	38.2%	745	46.9%
	≥3	217	7.2%	47	3.4%	165	10.4%
	Unknown	4	0.1%	2	0.1%	2	0.1%
Margins	Positive	104	3.5%	43	3.1%	59	3.7%
	Close (≤2mm)	449	15.0%	170	12.4%	271	17.1%
	>2–10mm	888	29.6%	384	27.9%	498	31.4%
	>10mm	1347	45.0%	669	48.7%	672	42.3%
	Unknown	208	6.9%	108	7.9%	88	5.5%
Radiation	No	1374	45.9%	1374	100%	0	0%
	Yes	1588	53.0%	0	0%	1588	100%
	Unknown	34	1.1%	0	0%	0	0%
Endocrine therapy	No	2321	77.5%	1152	83.8%	1163	73.2%
	Yes	628	21.0%	210	15.3%	417	26.3%
	Unknown	47	1.6%	12	0.9%	8	0.5%
Year of surgery	1978–2000	1067	35.6%	592	43.1%	454	28.6%
	2001–2010	1929	64.4%	782	56.9%	1134	71.4%

^aNumbers do not sum to 2996 due to unknown receipt of radiation in 34 women.