Table 1 Clinicopathologic characteristics of patients with PABC and non-PABC

Age at diagnosis

0.822

  ≤ 35

45(71.4%)

88(69.8%)

  > 35

18(28.6%)

38(30.2%)

Median age

32

33

0.495

Median age at menarche

13

13

0.305

Family history of breast cancer

0.293

 Yes

8(12.7%)

10(7.9%)

 No

55(87.3%)

116(92.1%)

Childbearing history

0.131

 Yes

56(88.9%)

101(80.2%)

 No

7(11.1%)

25(19.8%)

Tumor size

 < 0.001

 Tis

0 (0%)

3(2.4%)

 T1

13(20.6%)

63(50.0%)

 T2

43(68.3%)

57(45.2%)

 T3

4(6.3%)

3(2.4%)

 T4

3(4.8%)

0(0%)

Lymph node metastasis

0.016

 N0

26(41.3%)

73(57.9%)

 N1

16(25.4%)

28(22.2%)

 N2

14(22.2%)

9(7.1%)

 N3

7(11.1%)

16(12.7%)

Distant metastasis

0.209

 M0

61(96.8%)

126(100.0%)

 M1

2(3.2%)

0(0.0%)

TNM stage

0.006

 0

0(0%)

3(2.5%)

 I

10(15.9%)

41(32.5%)

 II

30(47.6%)

57(45.2%)

 III

21(33.3%)

25(19.8%)

 IV

2(3.2%)

0(0%)

ER

0.109

 Positive

35(55.6%)

85(67.5%)

 Negative

28(44.4%)

41(32.5%)

PR

0.061

 Positive

30(47.6%)

78(61.9%)

 Negative

33(52.4%)

48(38.1%)

Her-2

0.749

 Positive

41(65.1%)

79(62.7%)

 Negative

22(34.9%)

47(37.3%)

Ki-67

0.208

  ≥ 14%

53(84.1%)

96(76.2%)

  < 14%

10(15.9%)

30(23.8%)

Molecular subtype

0.536

 Luminal A

4(6.3%)

8(6.3%)

 Luminal B(Her-2 +)

23(36.5%)

58(46.0%)

 Luminal B (high ki-67)

9(14.3%)

22(17.5%)

 Her-2 overexpression

16(25.4%)

22(17.5%)

 TNBC

11(17.5%)

16(12.7%)