Table 4 Clinical, pathological and immunohistochemical characteristics of breast cancer patients and tumours for the subgroup with HER2-negative tumours at diagnosis, by changes in the HER2 status between the primary and recurrent tumour and by the type of relapse.

From: Anticipating changes in the HER2 status of breast tumours with disease progression—towards better treatment decisions in the new era of HER2-low breast cancers

Parameter

Primary tumours which relapsed as local recurrences

Primary tumours which relapsed as distant metastases

 

HER2-low relapse (n = 32)

HER2-negative relapse (unchanged HER2 status) (n = 29)

HER2-low relapse (n = 58)

HER2-negative relapse (unchanged HER2 status) (n = 75)

Age at diagnosis (years)

    

     Mean ± SD

52.4 ± 11.8

60.8 ± 17.1

55.0 ± 11.1

56.0 ± 12.4

     Median [min–max]

51.5 [26.0–79.0]

66.0 [34.0–89.0]

56.0 [29.0–81.0]

56.0 [26.0–87.0]

 P values

0.057

0.628

Unifocal tumour

    

     Yes

28 (87.5%)

27 (93.1%)

47 (81.0%)

58 (77.3%)

     No

4 (12.5%)

2 (6.9%)

11 (19.0%)

17 (22.7%)

 P values

0.674

0.604

Histology

    

     IDC

26 (81.2%)

23 (79.4%)

39 (67.2%)

56 (74.7%)

     ILC

6 (18.8%)

5 (17.2%)

16 (27.6%)

16 (21.3%)

     Other

0 (0.0%)

1 (3.4%)

3 (5.2%)

3 (4.0%)

 P values

0.866

0.651

Tumour size (cm)

    

     Mean ± SD

1.6 ± 1.0

1.8 ± 1.1

2.5 ± 1.4

3.1 ± 2.4

     Median [min–max]

1.3 [0.4–4.5]

1.5 [0.1–4.3]

2.0 [0.7–6.5]

2.3 [0.2–10.5]

     Missing data

0

0

3

1

 P values

0.358

0.321

E&E grade

    

     I

8 (25.0%)

7 (24.1%)

12 (21.1%)

11 (15.3%)

     II

14 (43.8%)

10 (34.5%)

34 (59.6%)

36 (50.0%)

     III

10 (31.3%)

12 (41.4%)

11 (19.3%)

25 (34.7%)

     Missing data

0

0

1

3

 P values

0.681

0.146

Glandular differentiation

    

     I

2 (6.2%)

2 (6.9%)

0 (0.0%)

1 (1.4%)

     II

8 (25.0%)

7 (24.1%)

19 (33.3%)

17 (23.3%)

     III

22 (68.8%)

20 (69.0%)

38 (66.7%)

55 (75.3%)

     Missing data

0

0

1

2

 P values

1.000

0.279

Nuclear grade

    

     I

3 (9.4%)

4 (13.8%)

3 (5.3%)

3 (4.1%)

     II

21 (65.6%)

13 (44.8%)

40 (70.2%)

47 (64.4%)

     III

8 (25.0%)

12 (41.4%)

14 (24.6%)

23 (31.5%)

 Missing data

0

0

1

2

 P values

0.260

0.662

Mitosis score

    

     I

16 (50.0%)

15 (51.7%)

32 (56.1%)

26 (35.6%)

     II–III

16 (50.0%)

14 (48.3%)

25 (43.9%)

47 (64.4%)

     Missing data

0

0

1

2

 P values

0.893

0.020

Mitotic index (/mm²)

    

     Mean ± SD

7.7 ± 8.0

7.3 ± 9.6

3.1 ± 3.6

7.3 ± 9.6

     Median [min–max]

5.7 [0.4–28.2]

2.2 [0.4–27.0]

1.9 [0.4–16.0]

4.2 [0.4–50.0]

     Missing data

12

10

23

24

 P values

0.573

0.008

Lymph node status

    

     N0–N0i+

23 (71.9%)

20 (69.0%)

28 (48.3%)

32 (50.0%)

     N1–N1mic

8 (25.0%)

9 (31.0%)

18 (31.0%)

25 (32.7%)

     N2–N3

1 (3.1%)

0 (0.0%)

12 (20.7%)

18 (17.3%)

 P values

0.570

0.802

Disease stage

    

     I

20 (62.5%)

17 (58.6%)

19 (32.8%)

20 (26.7%)

     II

9 (28.1%)

6 (20.7%)

22 (37.9%)

25 (33.3%)

     III

3 (9.4%)

6 (20.7%)

16 (27.6%)

21 (28.0%)

     IV

0 (0.0%)

0 (0.0%)

1 (1.7%)

9 (12.0%)

 P values

0.509

0.157

Oestrogen receptor expression

    

     Negative

7 (21.9%)

7 (24.1%)

3 (5.2%)

20 (27.0%)

     Positive

25 (78.1%)

22 (75.9%)

55 (94.8%)

54 (73.0%)

     Missing data

0

0

0

1

 P values

0.834

0.001

Progesterone receptor expression

    

     Negative

8 (25.0%)

11 (39.3%)

17 (34.7%)

24 (34.3%)

     Positive

24 (75.0%)

17 (60.7%)

32 (65.3%)

46 (65.7%)

     Missing data

0

1

9

6

 P values

0.235

0.963

Ki67 expression

    

     Mean ± SD

42.5 ± 20.4

28.8 ± 26.6

28.7 ± 19.6

32.8 ± 22.9

     Median [min–max]

40.0 [20.0–80.0]

20.0 [8.0–90.0]

25.0 [1.0–80.0]

30.0 [1.0–90.0]

     Missing data

24

19

66

78

 P values

0.108

0.047

Metastatic site

    

     Liver

17 (29.3%)

19 (25.3%)

     Bone

9 (15.5%)

18 (24.0%)

     Skin and muscle

9 (15.5%)

15 (20.0%)

     Lymph nodes

11 (19.0%)

7 (9.3%)

     Lung and pleura

4 (6.9%)

6 (8.0%)

     Gynaecological tract

3 (5.2%)

4 (5.3%)

     Gastrointestinal tract

4 (6.9%)

1 (1.3%)

     Brain

0 (0.0%)

1 (1.3%)

     Other

1 (1.7%)

4 (5.3%)

 P values

0.402

Time to recurrence (months)

    

     Mean ± SD

101.3 ± 61.4

66.9 ± 54.8

84.2 ± 49.8

68.7 ± 51.1

     Median [min–max]

88.0 [14.0–215.0]

48.0 [6.0–212.0]

75.0 [2.0–240.0]

57.0 [1.0–204.0]

 P values

0.013

0.051

  1. E&E Elston and Ellis, HER2 human epidermal growth factor receptor 2, IDC invasive ductal carcinoma, ILC invasive lobular carcinoma, SD standard deviation.
  2. Values in bold italic show statistically significant P-values.