c-erbB2 expression predicts response to preoperative chemotherapy for locally advanced breast cancer

Background: Previous work suggests that the presence of c-erbB2 oncoprotein immunostaining and the proliferation rate of rumours, may be relevant to c hemo-sensitivity in breast cancer. Patients and Methods: To investigate thi s we assessed pretreatment biopsies from 50 patients with locally advanced breast cancer for expression of c-erbB2 and MIB1 (proliferative marker) in relation to clinical response after 3 months preoperative chemotherapy Resu lts: Objective response was significantly more likely (22/30 73%) for tumou rs negative for c-erbB2 membrane staining, compared to positively staining rumours (6/20 30%, p = 0.0025). The percentage of cells staining positively for MIB1 was not predictive of response (p = 0.56). Conclusions: This stud y has shown an increased likelihood of response to preoperative chemotherap y for breast cancers negative for c-erbB2 staining. Previous studies have s hown that c-erbB2 immunostaining can correlate with either chemo-resistance or chemo- response. We postulate that this conflict may be due to differen ces in the type of chemotherapy administered. This raises the possibility o f biological markers being use to assist in the selection of the type of ch emotherapy regimen administered to particular tumour biological phenotype.