Her-2/neu expression in locally advanced breast carcinomas: pre- and post-neoadjuvant chemotherapy

Abstract

Clinical studies have shown a correlation of HER-2/neu amplification/over-expression and favorable response to neoadjuvant chemotherapy and anti-HER-2/neu antibody treatment. However, contradictory findings also have been reported. Some tumors may develop resistance to neoadjuvant chemotherapy after an initial period of sensitivity. Our study attempts to evaluate the effects of neoadjuvant chemotherapy on HER-2/neu status in locally advanced breast cancer. Thirty-nine patients with locally advanced breast cancers established by core needle biopsy received neoadjuvant chemotherapy and were compared with 60 patients with breast cancers who did not receive neoadjuvant chemotherapy. IHC for HER-2/neu was performed on paraffin sections of the core biopsy before treatment and the excised specimen following chemotherapy and scored as Negative (0-1+), 2+ and 3+. The results of the study and the controls were compared and analyzed using Fisher's exact test. HER-2/neu IHC scores decreased in 28.5% (15/39) of patients receiving neo-adjuvant chemotherapy compared to 11.7% (7/60) of patients in the control (p < 0.013). HER-2/neu IHC status changed from strongly positive to negative (3+ to 0) in five of 39 (12.5%) in the study group and in 2 of 60 (3.3%) in control group (p = 0.104). For patients receiving neoadjuvant chemotherapy in whom the tumor becomes refractory to chemotherapy or recurs, repeat testing for HER-2/neu status may be necessary. Elimination of HER-2/neu positive tumor cells may account for the changes in the IHC scores and the development of resistance to neoadjuvant chemotherapy.

Change in the hormone receptor status following administration of neoadjuvant chemotherapy and its impact on the long-term outcome in patients with primary breast cancer

“…The overall frequency of patients with HR status conversion was 16.0%. This incidence of HR status conversion was similar to previous reports on post-NAC change in the ER, PgR, and HER2 statuses, which reported incidences of 8 -28%, 6 -59% (Bottini et al, 1996;Lee et al, 2003;Taucher et al, 2003;Colleoni et al, 2004;Burcombe et al, 2005;Shet et al, 2007;Kasami et al, 2008;Neubauer et al, 2008), and 0 -21% (Bottini et al, 1996;Colleoni et al, 2004;Arens et al, 2005;Burcombe et al, 2005;Quddus et al, 2005;Adams et al, 2008;Kasami et al, 2008;Neubauer et al, 2008), respectively. Although the rate of cases with no change in the HR status after NAC was high, the incidence of change in the HR status is clinically not negligible.…”

Effect of neoadjuvant chemotherapy on stromal CD10 antigens in breast cancer - A preliminary study

“…[2] Changes in status of hormone receptors and HER2 are seen after chemotherapy in studies, with ER and PR increasing after chemotherapy and HER2 decreasing after chemotherapy. [3,4] CD10 is a zinc-dependent peptidase (metalloproteinase). CD10 positivity has been reported in myoepithelial cells from normal breast tissue and benign myoepithelial tumours.…”

Comparison of the IHC, FISH, SISH and qPCR methods for the molecular diagnosis of breast cancer

“…However, Her2 status does predict a favorable response to chemotherapy and anti-Her2 antibody treatment (9), since the humanized anti-Her2 antibody binds to the Her2 receptor, thereby preventing heterodimerization and interrupting the downstream signaling pathway. Moreover, the bound antibody induces FcR-mediated cytotoxicity (8).…”