Table 1 Baseline characteristics of the stratified neoadjuvant and adjuvant radiotherapy cohorts

Age, years

58.6 ± 12.9

59.5 ± 12.2

<0.0001^a

Year of diagnosis

1995.7 ± 7.2

2003.1 ± 6.5

<0.0001^a

 White

2348

(91.9%)

206,775

(83.5%)

<0.0001^b

 Black

127

(5%)

21,169

(8.5%)

<0.0001^b

 Other

79

(3.1%)

19,697

(8%)

<0.0001^b

 Positive

1368

(53.6%)

168,797

(68.2%)

<0.0001^b

 Negative

353

(13.8%)

34,494

(13.9%)

0.88^b

 Unknown

833

(32.6%)

44,350

(17.9%)

<0.0001^b

 Positive

1209

(47.3%)

144,228

(58.2%)

<0.0001^b

 Negative

492

(19.3%)

54,473

(22%)

0.0009^b

 Unknown

853

(33.4%)

48,940

(19.8%)

<0.0001^b

 Carcinoma in situ

344

(13.5%)

52,691

(21.3%)

<0.0001^b

 T1

1390

(54.4%)

146,954

(59.3%)

<0.0001^b

 T2

294

(11.5%)

30,683

(12.4%)

0.1798^b

 T3

49

(1.9%)

3034

(1.2%)

0.0016^b

 Unknown

477

(18.7%)

14,279

(5.8%)

<0.0001^b

 Ductal

2215

(86.7%)

213,143

(86.1%)

0.3397^b

 Lobular

146

(5.7%)

14,270

(5.8%)

0.9212^b

 Other

193

(7.6%)

20,228

(8.2%)

0.2614^b

 Partial mastectomy

2192

(85.8%)

233,946

(94.5%)

<0.0001^b

 Mastectomy

269

(10.5%)

10,632

(4.3%)

<0.0001^b

 Other

93

(3.6%)

3063

(1.2%)

<0.0001^b