Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.1.108 (TAT)
 2,389 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As reported by the Early Breast Cancer Trialists' Collaborative Group (EBCTCG) in Lancet (1992), the 10-year relapse-free survival or overall survival was significantly better in the tamoxifen (TAM) treatment group than in the control group in both node-positive and -negative groups. Adjuvant TAM treatment works better on patients over 50 years of age. Adjuvant TAM treatment for over 2 years is more effective than less than that time. Some reports demonstrated that long-term TAM treatment caused an increase in the circulating estrogen levels of premenopausal patients. This increase blocked the antitumor effect of TAM in a dose dependent fashion in our animal models. Similar results were obtained in toremifene or TAT-59 in our animal models. These results show that antiestrogens are more effective for postmenopausal than premenopausal women. LH-RH agonist or aromatase inhibitor may be a promising adjuvant endocrine agent of breast cancer. Combination therapy of TAM and LH-RH agonist, or LH-RH agonist and aromatase inhibitor will be an effective new adjuvant endocrine therapy for breast cancer. The combination of endocrine therapy and biological response modifiers, or of endocrine therapy with vitamin D3 will be clinically used in the future.
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PMID:[Adjuvant endocrine therapy for breast cancer]. 774 97

The characteristics and clinical efficacies of new hormonal drugs and new treatment methods for breast cancer using tamoxifen (TAM) were described. The new anti-estrogens, such as trioxifen, toremifene and droloxifen, have equal or better clinical efficacy than TAM. They showed a high response rate in postmenopausal patients with no previous treatment or estrogen receptor positive tumors. They were occasionally effective for patients who relapsed after TAM treatment. Pure anti-estrogen ICI 164, 384, with fewer estrogenic agonistic properties than TAM, and anti-estrogen TAT-59, which has been developed in Japan, are under clinical investigation. Luteinizing hormone-releasing hormone agonists, such as leuprolide, buserelin, triptrelin and goserelin, are available for premenopausal patients, and showed a 37% response rate on average. The pure aromatase inhibitors, such as 4-hydroxyandrostenedione and CGS 16, 949 A, are available for postmenopausal patients, and showed 30% and 17% response rates on average, respectively. The new pure aromatase inhibitor ZD-1033 is also under clinical investigation. TAM or toremifene as well as the calcium antagonist verapamil were proved to overcome the multiple anticancer drug resistance caused by P-glycoprotein. Clinical studies for breast cancer using high-dose TAM as a potential modulator of drug resistance have already been started in Europe and the United States. Chemoprevention of breast cancer using TAM, which started in the U.S., was described.
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PMID:[Recent development of endocrine treatment for breast cancer--new drugs and new treatment methods using tamoxifen]. 825 41

Experimental and epidemiological studies have pointed to a major role of estrogens in the pathogenesis of human breast cancer. The Oxford meta-analysis (1998) once again confirmed the efficacy of antiestrogens (tamoxifen) as adjuvant therapy. We need to know whether the new non-steroid antiestrogens (idoxifen, droloxifen and TAT-59) and selective estrogen receptor modulator (raloxifen), whith preclinical characteristics better than those of tamoxifen will be more efficient clinically. Large-scale trials to compare the new drugs with tamoxifen are under way. Faslodex, a pure antiestrogen, looks highly promising, too. Zoladex, a luteinising hormone-releasing hormone agonist, is looking as a better choice than ovariectomy or irradiation of the pelvis for ovarian ablation in premenopausal breast cancer. New aromatase inhibitors are more efficient than progestins and much safer than aminoglutethimide. It has been shown recently that these inhibitors keep metastatic breast cancer at bay longer, and with longer survival. The non-steroid inhibitors (anastrozole and letrozole) and the steroid oral drug exemestane are undergoing clinical trials as means of adjuvant treatment of breast cancer. The trial of arimidex and tamoxifen administered alone or in combination (ATAC) is unique since it is using a combination of tamoxifen and an aromatase inhibitor (anastrozole). New methods of endocrine therapy have resulted in less toxic and more convenient procedures. Also, longer therapeutic effects and survival are becoming more apparent.
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PMID:[Modern approaches to hormone therapy of breast cancer as a reflection of pathogenesis of the disease]. 1138 56