Metastatic breast cancer: an updating

Inhibition of focal adhesion kinase suppresses the adverse phenotype of endocrine-resistant breast cancer cells and improves endocrine response in endocrine-sensitive cells

“…However despite this, many patients progress during therapy due to acquired endocrine resistance [16]; in these patients, relapse on such therapies clinically presents as local and/or regional recurrences, frequently with distant metastases and the outlook for these patients is poor [17].…”

Dual targeting of Src and ER prevents acquired antihormone resistance in breast cancer cells

“…However, despite the undoubted improvements brought by endocrine therapies, in practice their benefits are limited by the capacity of a significant proportion of breast cancer patients that show an initial positive response to ultimately suffer a recurrence due to acquired antioestrogen resistance [3][4][5][6]. In these patients, relapse on such therapies clinically presents as local and/or regional recurrences, frequently with distant metastases [7] and the outlook for these patients is poor. Recent in vitro studies have demonstrated that chronic exposure of breast cancer cells to tamoxifen ultimately results in the acquisition of tamoxifen resistance [8,9] which is accompanied by the gain of aggressive, invasive characteristics [10,11].…”

Changes in and Prognostic Value of Hormone Receptor Status in a Series of Operable Breast Cancer Patients Treated with Neoadjuvant Chemotherapy

“…This discordance in HR status had an impact on the overall survival (OS) of these patients. Nicolini et al [7] found, in 10%-30% of cases, a conversion rate from estrogen receptor (ER) ϩ to ER Ϫ and from ER Ϫ to ER ϩ between the primary tumor and the metastatic relapse.…”