Table 3 Distribution of HER2 expression by IHC according to tumor phenotype in the HER2-low cohort.

From: Evolution of HER2-low expression from primary to recurrent breast cancer

 

HER2 expression n (%)

1+

2+

p

Primary breast cancer n (%)

HR-positive/HER2-negative

118 (63.1)

41 (21.9)

0.493

Triple-negative

19 (10.2)

9 (4.8)

Total

137 (73.3)

50 (26.7)

Recurrent breast cancer n (%)

HR-positive/HER2-negative

122 (59.8)

40 (19.6)

0.840

Triple-negative

33 (16.2)

9 (4.4)

Total

155 (76.0)

49 (24.0)