Table 2.

Comparison of HER2 expression in CTC and corresponding primary tumors

Primary tumors
HER2-negative (IHC 0, 1+ or FISH-negative)HER2-positive (IHC 3 + or FISH-positive)
Before NTAfter NTBefore NTAfter NT including trastuzumab
No. of CTC-positive cases analyzed (before/after NT)26111110
CTC HER2-negative (0)15 (57.7%)5 (45.4%)4 (36.4%)5 (50%)
CTC HER2-negative (1+)4 (15.4%)3 (27.3%)1 (9%)1 (10%)
CTC HER2 questionable (2+)2 (7.7%)03 (27.3%)1 (10%)
CTC HER2-strongly positive (3+)5 (19.2%)3 (27.3%)3 (27.3%)3 (30%)