Table 4 Univariate analysis of clinicopathological and US features of primary tumors and axillary nodal disease burden in the training set

Age(years)

0.355

  ≤ 50

137 (61.2%)

87 (38.8%)

  > 50

121 (56.8%)

92 (43.2%)

Histologic types

0.115*

 Ductal

244 (58.8%)

171 (41.2%)

 Lobular

4 (40.0%)

6 (60.0%)

 Others

10 (83.3%)

2 (16.7%)

Histologic grades

0.929*

 I

4 (66.7%)

2 (33.3%)

 II

119 (59.8%)

80 (40.2%)

 III

135 (58.2%)

97 (41.8%)

Molecular subtypes

0.277

 Luminal A

41 (60.3%)

27 (39.7%)

 Luminal B

112 (57.7%)

82 (42.3%)

 Luminal B HER2( +)

42 (71.2%)

17 (28.8%)

 HER2-enriched

35 (56.5%)

27 (43.5%)

 Triple negative

28 (51.9%)

26 (48.1%)

Multifocality

0.991

 Unifocal

206 (59.0%)

143 (41.0%)

 Multifocality

52 (59.1%)

36 (40.9%)

Tumor location

0.594

 Upper outer quadrant

171 (58.2%)

123 (41.8%)

 Others

87 (60.8%)

56 (39.2%)

Maximum diameter(cm)

0.889

  ≤ 2

78 (59.5%)

53 (40.5%)

  > 2

180 (58.8%)

126 (41.2%)

Shape

1.000*

 Irregular

256 (59.1%)

177 (40.9%)

 Oval and round

2 (50.0%)

2 (50.0%)

Orientation

0.066

 Parallel

228 (60.8%)

147 (39.2%)

 Not parallel

30 (48.4%)

32 (51.6%)

Angular margin

0.243

 Yes

75 (63.6%)

43 (36.4%)

 No

183 (57.4%)

136 (42.6%)

Spiculated margin

0.332

 Yes

92 (56.1%)

72 (43.9%)

 No

166 (60.8%)

107 (39.2%)

Distance from the skin

0.163

  < 3 mm

57 (53.3%)

50 (46.7%)

  ≥ 3 mm

201 (60.9%)

129 (39.1%)