Table 1.

Immunohistochemical expression of Estrogen Receptor (ER), Progesterone Receptor (PgR) and HER2 in pre- and post-treatment bioptical tissue samples from 4 HER2+, pertuzumab pretreated, advanced breast cancer patients

	Pre-treatment					Post-treatment
	ER	PgR	HER2 score	HER2%	FISH	ER	PgR	HER2 score	HER2%	FISH
Patient 1	90%	90%	2+	70%	amplified	90%	90%	0	0%	–
Patient 2	90%	40%	2+	30%	amplified	90%	60%	1+	30%	–
Patient 3	46%	0%	2+	100%	amplified	75%	18%	1+	15%	amplified
Patient 4	88%	42%	3+	100%	–	99%	1%	1+	60%	amplified