China
Africa
Explore chapters and articles related to this topic
Chlorophytum borivilianum (Musli) and Cimicifuga racemosa (Black Cohosh)
Published in Azamal Husen, Herbs, Shrubs, and Trees of Potential Medicinal Benefits, 2022
Rajib Hossain, Dipta Dey, Partha Biswas, Priyanka Paul, Shahlaa Zernaz Ahmed, Arysha Alif Khan, Tanzila Ismail Ema, Muhammad Torequl Islam
Antiestrogenic activity refers to the action of a compound that prevents estrogens such as estradiol from mediating their biological effects in the body. Antiestrogens, also called estrogen blockers or estrogen antagonists, are compounds that work by blocking estrogen receptors (ER) and decreasing estrogen synthesis; they have a positive impact on the body. For the treatment of menopausal symptoms, particularly hot flashes, black cohosh is becoming a more popular alternative to estrogen replacement therapy. In any of these test methods, black cohosh extracts showed no estrogenic action. This is a positive step forward in the evaluation of black cohosh's safety as a treatment for menopausal hot flashes (Lupu et al., 2003).A study was conducted using two independent cell-based estrogen inducible assays – transactivation assay and proliferation essay – and integrating data from an in vitro cell proliferation,providing evidence for potential antiestrogenic activities of extracts from the rhizome of C. racemosa(Zierau et al., 2002). Thus, it is believed that black cohosh may have antiestrogenic properties, but the researchers are trying to find out the exact mechanism.
Chemopreventive Agents
Published in David E. Thurston, Ilona Pysz, Chemistry and Pharmacology of Anticancer Drugs, 2021
Coumestrol has been considered for use as chemotherapy in breast cancer patients, and as a possible substitute for hormone replacement therapy (HRT). However, as with other phytoestrogens, results from animal models of cancer have been ambiguous and contradictory. In particular, there is concern that coumestrol could stimulate the growth of estrogen-sensitive breast tumors by interacting with the ERα receptor. In another study, researchers from Georgetown University Medical Center (USA) concluded that phytoestrogens such as coumestrol may have potential in the treatment of breast cancer due to its apoptotic properties (established in in vitro experiments) but would only be safe to administer after menopause when lower levels of estrogen are present. Alternatively, the researchers suggested it should only be administered in combination with antiestrogen therapies. Overall, most researchers agree that further clinical research in animal and humans is needed before coumestrol can be recommended for use as part of a breast cancer therapy.
Breast Imaging with Radiolabeled Estrogen Receptor Ligands
Published in Raymond Taillefer, Iraj Khalkhali, Alan D. Waxman, Hans J. Biersack, Radionuclide Imaging of the Breast, 2021
Klemens Maria Scheidhauer, Anton Scharl
The good quantitative correlation between in vitro measurements of estrogen receptor concentration and in vivo PET readings could not be reproduced in McGuire's next study performed by the same research group on patients with metastases of a mammary carcinoma. A number of factors could explain this: for one, the in vitro values were obtained from primary tumors, but the receptor content of primary tumor tissue and metastases differ in 20% to 25% of patients [47]. The sensitivity of receptor scintigraphy was 93% in 57 metastases (n = 16 patients), which is indeed high. However, the presence of a receptor-positive primary tumor was one of the criteria for inclusion in the study. Two false-positive findings were reported (radiation fibrosis and a fatigue fracture), but, in this study, only small axial areas of 10 or 20 cm were scanned. Seven patients were given a further scan after commencement of hormone therapy with antiestrogen (= receptor blockade). In each case this led to a marked reduction of activity—on average by almost two-thirds of the original level. This is evidence of the high specificity of the tracer used for the receptor [46].
Addressing the problem of overtreatment in breast cancer
Published in Expert Review of Anticancer Therapy, 2022
Another area of concern regarding overtreatment in DCIS is the use of endocrine therapy. Two randomized controlled trials have demonstrated the benefit of tamoxifen in reducing both ipsilateral and contralateral breast events following excision of DCIS. After a median follow-up of 14.6 years, the NSABP B-24 trial demonstrated a significant reduction in the rate of invasive breast cancer (no tamoxifen 19%, tamoxifen 12%) but not in the rate of DCIS (12% versus 9%, p = 0.12) [84]. The UK/ANZ DCIS trial demonstrated a reduction in 10-year risk of recurrent ipsilateral DCIS (no tamoxifen 12.1%, tamoxifen 8.6%) and contralateral tumors (4.2% versus 1.9%), but not of ipsilateral invasive disease (6.9% versus 6.8%) [85]. No difference in survival was seen in either trial. Tamoxifen and other anti-estrogen therapies have side effects, including vasomotor symptoms, thromboembolic events, and endometrial cancer. For many women, these side effects outweigh the small absolute reduction in new invasive events. Uptake of endocrine therapy for DCIS is relatively low, ranging from 21% to 47% [86]. Endocrine therapy should be discussed as an option for those who wish to minimize the risk of future breast cancer events and have a favorable risk-benefit ratio for treatment (premenopausal, 2 breasts at risk), but should not be considered a mandatory part of DCIS management.
Evaluation of aromatase inhibitor on radiation induced pulmonary fibrosis via TGF- β/Smad 3 and TGF- β/PDGF pathways in rats
Published in Toxicology Mechanisms and Methods, 2021
Shereen M. Elkiki, Heba H. Mansour, Lobna M. Anis, Hanan M. Gabr, Mona M. Kamal
The use of endocrine treatment and radiation for breast adjuvant treatment particularly due to resultant pulmonary toxicity and subcutaneous tissue toxicity is a matter of concern. Aromatase inhibitors (AIs) have been recommended as a part of standard treatment in the adjuvant systemic therapy of postmenopausal women with endocrine responsive early breast cancer and also, (AIs) have been shown to be superior to nonsteroidal antiestrogen Tamoxifen (TAM) (Coates et al. 2007; Forbes et al. 2008). Although the pulmonary fibrosis of RT worsens when used with concurrent tamoxifen, there are no data regarding to pulmonary toxicities of AIs but aromatase inhibitors have been shown to have a disease-free survival benefit in post-menopausal women (Dowsett et al. 2010). Altinok et al. (2016) stated that number of studies concerning the use of AIs alongside of RT is quite limited compared to those that deal with TAM and insufficient data is available regarding the toxicity of concurrent use of AIs and radiation therapy (RT).
Clinically feasible and prospective immunotherapeutic interventions in multidirectional comprehensive treatment of cancer
Published in Expert Opinion on Biological Therapy, 2021
Victor I. Seledtsov, Alexei von Delwig
Anti-hormonal strategies with a profound impact on cancer in clinical settings are based on using drugs that suppress hormonal proliferative signals, such as anti-androgen anti-estrogen therapies for prostate and breast cancer, respectively. Androgen-deprivation therapy is a current standard of care, which aims to remove circulating androgens that drive prostate cancer growth. Indeed, androgens possess immunosuppressive properties, thus laying a foundation for an anti-androgen therapy-mediated stimulation of anti-tumor immune reactivity. Consistent with this notion, combinations of anti-androgen therapy with checkpoint molecule inhibition have shown moderate success in prostate cancer treatment. When combined with anti-androgen therapy, vaccine-based approaches also exhibited detectable immunological and clinical efficiency [142]. Anti-estrogen therapy combined with cytotoxic anti-human epidermal growth factor receptor 2 (HER2) Abs (a common breast cancer treatment) was shown to stimulate anti-tumor immune responses and improved pathologic response rates in patients with HER2pos/ERpos early breast cancer [44]. An addition of anti-estrogen therapy to anti-HER2 dendritic cell vaccination improved regional nodal immune responses and pathologic complete response rates in patients with HER2pos breast cancer [143]. Different immune-based interventions in combination with anti-hormone therapy are currently investigated in clinical studies.