Her2/neu Expression Predicts the Response to Antiaromatase Neoadjuvant Therapy in Primary Breast Cancer

Abstract

Purpose: Many studies suggest that Her2/neu play an important role in neoadjuvant endocrine therapy. This study aimed to determine whether the level of Her2/neu expression in advanced breast cancer changes after antiaromatase neoadjuvant treatment, as well as to identify the relationship between Her2/neu expression and response to this kind of therapy.Experimental Design: Thirty-six postmenopausal patients with hormonal receptor-positive primary breast cancer were included in a study of three monthly cycles of neoadjuvant endocrine therapy with either Aromasin (25 mg daily) or Femara (2.5 mg daily). Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) for Her2/neu were conducted both on pretreatment biopsies and surgical tumors.Results: Using IHC, 5 of 36 (13.9%) of the patients had a Her2/neu overexpression after treatment, as compared with 16 of 36 (44.4%) before. Meanwhile, there was no change in 21 (58.3%) patients, and through FISH, there was a change from amplification to no amplification in 15 (41.7%) patients. The response rate to the treatment was 75% for Her2/neu (؉) tumors and 35% for Her2/neu (؊) tumors (P ‫؍‬ 0.017) while FISH was performed. The response rate was also significantly affected by the decrease in Her2/neu status after the treatment, with 73% of the tumors showing decreased Her2/neu expression and with 38% of the tumors showing no change of Her2/neu expression (P ‫؍‬ 0.037).Conclusions: Using both IHC and FISH, advanced breast cancers show statistical evidence of decreasing incidence of Her2/neu expression after antiaromatase neoadjuvant treatment. Our data also suggest that Her2/neu expression and its change during the treatment might be predictive markers for this kind of therapy.

Mechanisms of Tumor Regression and Resistance to Estrogen Deprivation and Fulvestrant in a Model of Estrogen Receptor–Positive, HER-2/neu-Positive Breast Cancer

“…Three recently completed neoadjuvant trials also suggest that estrogen deprivation therapy is very effective in the subset of patients with tumors amplified for HER-2/neu (22)(23)(24). Although the HER-2/neu-positive subgroups in each study had small numbers of patients, they all show very high response rates to the aromatase inhibitors letrozole and anastrozole in the HER-2/ neu-positive subset and much lower response rates to tamoxifen.…”

The Anti-Cancer Effect of COX-2 Inhibitors on Gastric Cancer Cells

“…Currently, COX-2 inhibitors including celecoxib are being used. That is, various combination of conventional chemotherapy with celecoxib are being studied [48][49][50][51][52][53][54][55][56][57][58][59] and clinical benefits are being certified [49,52,54,[57][58][59], suggesting that a possible cancer preventive effect of celecoxib should not be confused with the side effect of rofecoxib.…”

Molecular Mechanism and Clinical Implications of Endocrine Therapy Resistance in Breast Cancer

“…In a different neoadjuvant study in locally advanced breast cancer patients, levels of HER2 expression before and after AI treatment were analyzed and related to the clinical outcome of the patients [73]. Using both immunohistochemistry and fluorescence in situ hybridization (FISH), data from this study showed that response to the treatment was significantly influenced by HER2 status, with a response rate of 75% for HER2-positive and 35% for HER2-negative tumors (p = 0.017).…”