Table 1 Clinicopathological characteristics of the control group and study group invasive micropapillary carcinoma

Age at diagnosis (years)

<0.001

 ≤50

94 (58)

969 (42)

 >50

69 (42)

1330 (58)

Tumor size (mm)

0.012

 ≤20

26 (17)

591 (37)

 20–50

102(68)

1385 (62)

 >50

22 (15)

255 (11)

IMPC proportion

<0.001

 ≤25%

32 (20)

1148 (50)

 26–50%

39 (24)

560 (25)

 51–75%

38 (23)

156 (7)

 >75%

54 (33)

412 (18)

No of LNM

<0.01

 0

26 (16)

722 (32)

 1–3

30 (19)

563 (25)

 ≥4

105 (65)

982 (43)

TNM stage

0.156

 I

17 (11)

372 (16)

 II

70 (43)

924 (41)

 III–IV

74 (46)

964 (43)

Histologic grade

0.379

 I

32 (20)

413 (18)

 II

88 (54)

1398 (62)

 III

42 (26)

454 (20)

ER

<0.001

 −

52 (32)

318 (15)

 +

111 (68)

1818 (85)

PR

<0.001

 −

59 (36)

473 (22)

 +

104 (64)

1658 (78)

HER-2

0.390

 0/1+

96 (60)

1341 (63)

 2+

53 (33)

606 (29)

 3+

11 (7)

184 (9)

LVI

0.030

 −

76 (47)

1746 (55)

 +

87 (53)

530 (45)

LNM with ECE

0.163

 −

103 (63)

1507 (68)

 +

60 (37)

694 (32)

Local regional recurrence

20 (12)

56 (5)

<0.001

Distant metastasis

68 (42)

96 (9)

<0.001

Died of disease

76 (47)

89 (8)

<0.001

Surgery type

0.001

 Breast-conserving surgery/Lumpectomy

5 (3)

16 (1)

 Mastectomy

158 (97)

2283 (99)

Chemotherapy (adjuvant/ neoadjuvant)

0.516

 0

13 (8)

153 (7)

 1

150 (92)

2146 (93)

Radiation therapy

0.206

 0

69 (42)

1060 (46)

 1

94 (58)

1239 (54)

Endocrine therapy

<0.001

 0

72 (47)

308 (15)

 1

80 (53)

1794 (85)