Table 1 Phenotypic characterization of breast tumors derived from BRCA2 germline mutation carriers

ER

8 (25%)

7 (22%)

17 (53%)

PR

12 (37%)

14 (44%)

6 (19%)

HER2

22 (69%)

10 (31%)

0 (0)

Cellular proliferation; The proportion of cells positive for Ki-67

Ki-67

0-14% (1st Qu.)

> 14%-35% (IQR)

> 35% (3rd Qu.)

Luminal

8 (33%)

14 (58%)

2 (8%)

Triple-negative

0 (0)

3 (37%)

5 (63%)

Χ² test; P = 0.004

Expression of basal features

EGFR

0

I

≥ II

Luminal

22 (96%)

1 (4%)

0 (0)

Triple-negative

4 (50%)

1 (13%)

3 (37%)

Χ² test; P = 0.004

CK5/6

Negative

Positive

Luminal

24 (100%)

0

Triple-negative

3 (37%)

5 (63%)

Χ² test; P = 0.0003

pRb/p16 pathway

p16 (CDKN2A)

0

I-II

III

Luminal A

3 (38%)

4 (50%)

1 (12%)

Luminal B

9 (60%)

5 (33%)

1 (7%)

Triple-negative

0

1 (12%)

7 (88%)

Χ² test; P = 0.0007

Cyclin-D1 (CCND1)

0-15% (1st Qu.)

> 15%-75% (IQR)

> 75% (3rd Qu.)

Luminal A

1 (12%)

4 (50%)

3 (38%)

Luminal B

1 (6%)

8 (50%)

7 (44%)

Triple-negative

6 (75%)

2 (25%)

0

Χ² test; P = 0.005

pRb (RB1)

0 (Negative)

I (Positive)

Luminal A

1 (13%)

7 (87%)

Luminal B

2 (13%)

14 (87%)

Triple-negative

4 (50%)

4 (50%)

Χ² test; P = 0.085

Morphologic features

Histologic grade

I

II

III

Luminal

2 (8%)

11 (44%)

12 (48%)

Triple-negative

1 (12%)

1 (12%)

6 (75%)

Χ² test, P = 0.27