Table 2.

HER2 gene amplification and hormone receptor status following trastuzumab containing neoadjuvant chemotherapy in patients with enough residual disease identified at the time of surgery to reassess HER2 status

Patient no.HER2 FISH ratio pretreatmentHER2 FISH ratio posttreatmentER* pretreatmentER posttreatment
13.171.96NEGNEG
26.064.78POSPOS
3POS (Aneuploid)POS (Aneuploid)POSPOS
47.196.22NEGPOS
53.701.94NEGNEG
62.881.24POSN/A
75.065.02POSPOS
85.265.26POSPOS
95.484.46POSPOS
105.411.32NEGPOS
115.041.26NEGN/A
1213.796.23POSPOS
134.704.25NEGPOS
1411.639.63POSPOS
152.392.42POSPOS
166.221.23NEGNEG
174.264.22NEGNEG
1811.651.28POSN/A
198.746.56POSPOS
206.524.26POSN/A
213.873.56NEGNEG
222.562.61NEGPOS
236.827.12POSPOS
242.961.29NEGNEG
252.782.38POSN/A

NOTE: Patients who lost HER2 amplification are identified in bold.

Abbreviations: POS, positive; NEG, negative; N/A, not enough residual tumor available to assess.

  • *ER status was determined by immunohistochemical analysis. Nuclear staining ≥ 10% was considered positive.

  • Due to marked aneuploidy of tumor cells and clustering of signals, HER2/neu and CEP17 signals could not be accurately counted; however, there was at least a 2-fold increase in the number of signals for HER2/neu compared with CEP17.