Progress in endocrine therapy for breast carcinoma

Abstract

In the endocrine therapy of breast cancer, there are two kinds of drugs which are commonly used, tamoxi-fen and toremifene. Tamoxifen had been approved by the U.S. Food and Drug Administration as a kind of selective estrogen receptor modulators as early as 1977. It was used in the treatment of advanced breast cancer with hormone receptor positive, nevertheless as the first generation of selective estrogen receptor modula-tors, TAM produced antagonistic action of estrogen in breast tissue. Meanwhile, estrogenic activity was also produced in the uterus and bone, thus caused other adverse events like genital lesions (for example, the increasing risk of endometrial cancer) at the same time while treating breast cancer. Toremifene was a kind of estrogen receptor regulator which was approved by the FDA for the treatment of breast cancer after TAM. It had been used in the clinical adjuvant therapy on breast cancer since 1995. Recently, a number of domestic and foreign studies have discussed the similar efficacy and adverse reactions of TOR and TAM in the treatment of breast cancer in various stages. This article will summarize relevant literature and data from four aspects, the efficacy, safety, quality of life and economic benefits, and to discuss the clinical progress of toremifene and tamoxifen in endocrine therapy for breast cancer. Abstract Researches on the breast cancer pathogenesis have been greatly progressed within the past few decades, so does the immunohistochemical classification of breast cancer. Recent clinical trials and studies have shown that endocrine therapy has become a clear target treatment with confirmed efficacy of breast cancer. In the drug selection of endocrine therapy for breast cancer, tamoxifen and toremifene have been approved by the U.S. Food and Drug Administration (FDA) successively on the treatment of peri-menopausal breast cancer patients with positive hormone receptor. A number of domestic and foreign researches have been done in comparison of using toremifene and tamoxifen alone, or both in the endocrine therapy for breast cancer; however results and conclusions vary among different studies. This article will mainly focus on reviewing literatures of this field from four aspects, the efficacy, safety, quality of life and economic benefits, and discussing the clinical progress of toremifene and tamoxifen in endocrine therapy for breast cancer.

Fulvestrant in heavily pre-treated patients with advanced breast cancer: results from a single compassionate use programme centre

“…As a consequence, the sequential use of non-cross-resistant hormonal treatments was evaluated in phase II trials in the palliative setting. Such treatment appeared to be effective in terms of overall patient outcome and quality of life, especially in patients with less aggressive disease [1][2][3].…”

Factors affecting progression-free survival in hormone-dependent metastatic breast cancer patients receiving high-dose chemotherapy and hematopoietic progenitor cell transplantation: role of maintenance endocrine therapy

“…The availability of newer hormonal compounds, with increased efficacy and improved tolerance, may provide more therapeutic options for MET in patients who have previously progressed during hormonal treatment. [17][18][19][20][21][22] We found a trend towards longer OS in patients receiving MET (Figure 1a), which may become significant with longer follow-up. We speculate that, since treatment upon progression after HDCT is expected to have only a marginal effect on the natural history of metastatic breast cancer, 23 delaying disease progression by maintenance therapy might eventually result in longer survival.…”

Epigenetics and the Estrogen Receptor

“…31 Furthermore, tamoxifen-resistant tumors show a shorter relapse of survival in samples with low expression of NCoR. 20 Unfortunately though, 30% of breast cancers are ER␣-negative upon diagnosis 22 and many breast cancers can lose ER␣ expression during progression of the cancer. In many patients epigenetic modification plays a role in the loss of ER␣ gene expression.…”