HER2 Low Expression in Primary Male Breast Cancer

Figures & data

Figure 1 HER2-testing in primary male breast cancer.

Figure 2 HER2 expression in primary male breast cancer.

Notes: *FISH negative, **FISH positive.

Abbreviation: FISH, fluorescence-in-situ-hybridization.

Table 1 Patient Characteristics Correlated with HER2 Expression in Primary Male Breast Cancer

	n (%)	HER2 Zero, n (%)	HER2 Ultralow, n (%)	HER2 Low, n (%)	HER2 Positive (3+), n (%)	p-value
Age (median 66 y)
≤66 y		16 (26.7)	24 (20.0)	19 (15.8)	1 (0.8)	0.11
>66 y		18 (30)	19 (15.8)	20 (16.7)	3 (2.5)
Tumor size
pT1	35 (43.2)	12 (34.3)	13 (37.1)	9 (25.7)	1 (2.9)	0.91
pT2	28 (34.6)	6 (21.4)	11 (39.3)	10 (35.7)	2 (7.1)
pT3	3 (3.7)	0	1 (33.3)	1 (33.3)	1 (33.3)
pT4	15 (18.5)	4 (26.7)	5 (33.3)	6 (40.0)	0
Nodal stage
pN0	36 (36.4)	12 (33.3)	11 (30.6)	12 (33.4)	1 (2.8)	0.67
pN1	44 (44.4)	10 (22.7)	20 (45.5)	12 (27.3)	2 (4.5)
pNx	19 (19.2)	4 (21.1)	8 (42.1)	6 (31.6)	1 (5.3)
Grading
1	9 (7.5)	4 (44.4)	5 (55.6)	0	0	0.15
2	84 (70.0)	20 (23.8)	32 (38.1)	30 (35.7)	2 (2.4)
3	27 (22.5)	8 (29.6)	8 (29.6)	10 (37.0)	1 (3.7)
ER
Positive	119 (99.1)	29 (24.4)	45 (37.8)	38 (31.9)	3 (2.5)	0.17
Negative	1 (0.9)	0	0	0	1
PR
Positive	114 (95.0)	30 (26.4)	44 (38.6)	36 (31.6)	4 (3.5)	0.64
Negative	6 (5.0)	3 (50.0)	1 (16.7)	2 (33.3)	0
Ki67*
High	66 (55.0)	21 (33.3)	28 (40.0)	17 (26.7)	0	0.3
Low	54 (45.0)	15 (27.8)	19 (35.9)	16 (29.6)	4 (7.4)

Notes: Ki67* - Ki67 low <13.5%, Ki67 high ≥ 13.5%.

Abbreviations: Y, years; ER, estrogen receptor; PR, progesterone receptor.

Figure 3 Kaplan–Meier curves for overall survival in primary male breast cancer. (a) Estimated survival calculated for HER2 low and HER2 negative tumors. (b) Estimated survival calculated for HER2 low, HER2 ultralow, and HER2 zero tumors.