Table 3 Distribution of clinicopathological variables within groups of patients as revealed by hierarchical clustering

Distribution

Count

27

23

24

22

9

Age

Mean

64.3

58.3

59.6

55.7

55.4

   p⁵ = 0.235, p³ = 0.212, N = 105

Median

64

55

60

57

49

Tumor type

Lobular and mixed ductal/lobular

12

5

5

4

1

   p⁵ = 0.040*, p³ = 0.021*, N = 105

Ductal not otherwise specified

15

17

16

14

4

Mucinous, papillary

0

0

2

2

1

Medullary, spindle cell

0

1

1

2

3

Lymph node metastases

Absent

10

8

6

12

5

   p⁵ = 0.240, p³ = 0.065, N = 105

Present

17

15

18

10

4

Maximal tumor diameter

<20 mm (pT1)

6

11

12

13

0

   p⁵ = 0.001*, p³ = 0.408, N = 105

> 20 mm (pT2, pT3)

21

12

12

9

9

Tumor grade

Grade 1

8

5

7

7

2

   p⁵ = 0.138, p³ = 0.199, N = 105

Grade 2

14

7

10

5

1

Grade 3

5

11

7

10

6

Nuclear grade

Grade 1

6

2

2

6

2

   p⁵ < 0.001**, p³ < 0.001**, N = 105

Grade 2

17

15

20

9

0

Grade 3

4

6

2

7

7

Estrogen receptor alpha

Positive

25

18

24

15

3

   p⁵ < 0.001**, p³ < 0.001**, N = 105

Negative

2

5

0

7

6

Estrogen receptor beta

Positive

20

11

13

8

3

   p⁵ = 0.078, p³ = 0.030*, N = 99

Negative

7

8

10

13

6

Progesterone receptor

Positive

23

16

24

14

4

   p⁵ < 0.001**, p³ < 0.001**, N = 105

Negative

4

7

0

8

5

HER2 amplification by fluorescence in situ hybridization

Absent

25

16

22

19

9

   p⁵ = 0.071, p³ = 0.398, N = 105

Present

2

7

2

3

0

HER2/neu by immunohistochemistry

3+

2

5

2

3

0

   p⁵ = 0.008*, p³ = 0. 046*, N = 105

2+

0

3

3

2

0

1+

10

10

7

2

1

0

15

5

12

15

8

Cytokeratin 5/6 or cytokeratin 14

Positive

2

3

0

4

3

   p⁵ = 0.035*, p³ = 0.010*, N = 99

Negative

24

18

23

16

6

Triple-negative phenotype

Yes

0

1

0

5

6

   p⁵ < 0.001**, p³ < 0.001**, N = 105

No

27

22

24

17

3

Cyclin D₁ amplification by fluorescence in situ hybridization

Absent

22

21

18

17

9

   p⁵ = 0.354, p³ = 0.875, N = 102

Present

5

2

4

4

0

Cyclin D₁ by immunohistochemistry

Positive

26

17

21

18

4

   p⁵ = 0.001**, p³ = 0.111, N = 101

Negative

0

5

2

3

5

Mucin 1

2+

17

12

21

9

1

   p⁵ = 0.001**, p³ < 0.001**, N = 102

1+

9

10

2

7

7

0

1

0

0

5

1

Gross cystic fluid protein

Positive

10

10

13

9

2

   p⁵ = 0.572, p³ = 0.440, N = 98

Negative

15

13

10

10

6