Endocrine therapy for early breast cancer

Localized Therapeutic Approaches Based on Micro/Nanofibers for Cancer Treatment

Cancer remains one of the most challenging health problems worldwide, and localized therapeutic approaches based on micro/nanofibers have shown potential for its treatment. Micro/nanofibers offer several advantages as a drug delivery system, such as high surface area, tunable pore size, and sustained release properties, which can improve drug efficacy and reduce side effects. In addition, functionalization of these fibers with nanoparticles can enhance their targeting and therapeutic capabilities. Localized delivery of drugs and/or other therapeutic agents via micro/nanofibers can also help to overcome the limitations of systemic administration, such as poor bioavailability and off-target effects. Several studies have shown promising results in preclinical models of cancer, including inhibition of tumor growth and improved survival rates. However, more research is needed to overcome technical and regulatory challenges to bring these approaches to clinical use. Localized therapeutic approaches based on micro/nanofibers hold great promise for the future of cancer treatment, providing a targeted, effective, and minimally invasive alternative to traditional treatments. The main focus of this review is to explore the current treatments utilizing micro/nanofibers, as well as localized drug delivery systems that rely on fibrous structures to deliver and release drugs for the treatment of cancer in a specific area.

The regulation of microRNA in each of cancer stage from two different ethnicities as potential biomarker for breast cancer

miRNA has recently emerged as a potential biomarker for breast cancer. Even though many studies have identified ethnic variation affecting miRNA regulation, the effect of cancer stage within specific ethnicities on miRNA epigenetic remains unclear. The present study is designed to investigate miRNA regulation from two distinct ethnicities in specific cancer stages (non-Hispanic white and non-Hispanic black) using the TCGA dataset. Differentially expressed miRNAs were calculated by using the edgeR package. miRNAs with the highest or lowest log fold Change from each cancer stage were selected as a potential biomarker. miRNA-gene interaction was analyzed by using spearman correlation analysis, CLUEGO, and DIANA-mirpath. The association of biomarker candidates with diagnostic and prognostic performance was assessed using ROC and Kaplan-Meier survival analysis. miRNA-gene interaction analysis revealed the involvement of selected miRNAs in cancer progression. From eleven selected aberrant miRNAs, four of the miRNAs (hsa-mir-495, hsa-mir-592, hsa-mir-6501, and hsa-mir-937) are significantly detrimental to breast cancer diagnosis and prognosis. Hence, our result provides valuable information to explore miRNA's role in each cancer stage between non-Hispanic white and non-Hispanic black.

Notch Signaling in Breast Cancer: A Role in Drug Resistance

Breast cancer is a heterogeneous disease that can be subdivided into unique molecular subtypes based on protein expression of the Estrogen Receptor, Progesterone Receptor, and/or the Human Epidermal Growth Factor Receptor 2. Therapeutic approaches are designed to inhibit these overexpressed receptors either by endocrine therapy, targeted therapies, or combinations with cytotoxic chemotherapy. However, a significant percentage of breast cancers are inherently resistant or acquire resistance to therapies, and mechanisms that promote resistance remain poorly understood. Notch signaling is an evolutionarily conserved signaling pathway that regulates cell fate, including survival and self-renewal of stem cells, proliferation, or differentiation. Deregulation of Notch signaling promotes resistance to targeted or cytotoxic therapies by enriching of a small population of resistant cells, referred to as breast cancer stem cells, within the bulk tumor; enhancing stem-like features during the process of de-differentiation of tumor cells; or promoting epithelial to mesenchymal transition. Preclinical studies have shown that targeting the Notch pathway can prevent or reverse resistance through reduction or elimination of breast cancer stem cells. However, Notch inhibitors have yet to be clinically approved for the treatment of breast cancer, mainly due to dose-limiting gastrointestinal toxicity. In this review, we discuss potential mechanisms of Notch-mediated resistance in breast cancer cells and breast cancer stem cells, and various methods of targeting Notch through γ-secretase inhibitors, Notch signaling biologics, or transcriptional inhibitors. We also discuss future plans for identification of novel Notch-targeted therapies, in order to reduce toxicity and improve outcomes for women with resistant breast cancer.

Investigation of women with postmenopausal uterine bleeding: clinical practice recommendations

Postmenopausal uterine bleeding is defined as uterine bleeding after permanent cessation of menstruation resulting from loss of ovarian follicular activity. Bleeding can be spontaneous or related to ovarian hormone replacement therapy or to use of selective estrogen receptor modulators (eg, tamoxifen adjuvant therapy for breast carcinoma). Because anovulatory "cycles" with episodes of multimonth amenorrhea frequently precede menopause, no consensus exists regarding the appropriate interval of amenorrhea before an episode of bleeding that allows for the definition of postmenopausal bleeding. The clinician faces the possibility that an underlying malignancy exists, knowing that most often the bleeding comes from a benign source. Formerly, the gold-standard clinical investigation of postmenopausal uterine bleeding was institution-based dilation and curettage, but there now exist office-based methods for the evaluation of women with this complaint. Strategies designed to implement these diagnostic methods must be applied in a balanced way considering the resource utilization issues of overinvestigation and the risk of missing a malignancy with underinvestigation. Consequently, guidelines and recommendations were developed to consider these issues and the diverse spectrum of practitioners who evaluate women with postmenopausal bleeding. The guideline development group determined that, for initial management of spontaneous postmenopausal bleeding, primary assessment may be with either endometrial sampling or transvaginal ultrasonography, allowing patients with an endometrial echo complex thickness of 4 mm or less to be managed expectantly. Guidelines are also provided for patients receiving selective estrogen receptor modulators or hormone replacement therapy, and for an endometrial echo complex with findings consistent with fluid in the endometrial cavity.�

Cost-effectiveness of exemestane versus tamoxifen as adjuvant therapy for early-stage breast cancer after 2-3 years treatment with tamoxifen in Sweden

Aromatase inhibitors are rapidly becoming the cornerstone of endocrine treatment for advanced disease and are now also used as adjuvant treatment in early-stage disease. The objective of this study was to assess the cost-effectiveness of adjuvant treatment with exemestane versus tamoxifen for early-stage breast cancer after 2-3 years treatment with tamoxifen in Sweden. The results are based on findings in the Intergroup Exemestane Study (IES). IES was a randomized controlled trial in which postmenopausal women who had received 2-3 years of tamoxifen therapy following primary treatment of early-stage breast cancer, were randomized to either continue on tamoxifen therapy or be switched to exemestane therapy. The results showed a disease-free survival hazard ratio of exemestane relative to tamoxifen in IES of 0.69. A Markov state-transition model was developed to simulate consequences after the end of the clinical trial, and to integrate the trial data with external data on mortality, costs and quality of life specific for Swedish women. The cost per QALY gained was about euro 20,000 in the base case analysis without inclusion of consequences of coronary heart disease. Inclusion of these events increased the cost-effectiveness ratio to about euro 31,000. This means that, based on our assumption, sequential exemestane treatment in early breast cancer is a cost-effective option compared with tamoxifen alone, although more long-term data on overall survival and consequences of adverse events would be valuable to increase the validity of the analysis further.