Table 1 Demographic and clinical characteristics

Age at diagnosis

0.008

 ≤ 40

62

2.7

18

5.1

 41–55

501

21.6

89

25.1

 56–70

901

38.8

145

40.8

 71–85

722

31.1

89

25.1

 > 85

136

5.9

14

3.9

Race

< 0.001

 White

1901

81.9

273

76.9

 Black

266

11.5

70

19.7

 Other

144

6.2

11

3.1

 Unknown

11

0.5

1

0.3

Laterality

0.910

 Right

1211

52.2

184

51.8

 Left

1111

47.8

171

48.2

Marital status

0.331

 Married

1562

67.3

235

66.2

 Not married

662

28.5

110

31.0

 Unknown

98

4.2

10

2.8

Grade

< 0.001

 I

264

11.4

36

10.1

 II

1137

49.0

135

38.0

 III/IV

744

32.0

159

44.8

 Unknown

177

7.6

25

7.0

Tumor size

0.010

 T1

1110

47.8

146

41.1

 T2

906

39.0

149

42.0

 T3

96

4.1

21

5.9

 T4

145

6.2

34

9.6

 TX

65

2.8

5

1.4

Nodal status

0.034

 N0

1175

50.6

153

43.1

 N1

678

29.2

114

32.1

 N2

219

9.4

44

12.4

 N3

152

6.5

32

9.0

 NX

98

4.2

12

3.4

Metastasis

< 0.001

 M0

2172

93.5

311

87.6

 M1

150

6.5

44

12.4

Stage

< 0.001

 I

701

30.2

85

23.9

 II

968

41.7

137

38.6

 III

425

18.3

84

23.7

 IV

150

6.5

44

12.4

 Unknown

78

3.4

5

1.4

Surgery

0.623

 Done

2217

95.5

335

94.4

 Not

98

4.2

19

5.4

 Unknown

7

0.3

1

0.3

Radiation

0.089

 Done

613

26.4

109

30.7

 Not

1709

73.6

246

69.3

Chemotherapy

< 0.001

 Yes

848

36.5

181

51.0

 No/unknown

1474

63.5

174

49.0