Hormonal therapy in oncology is hormone therapy for cancer and is one of the major modalities of medical oncology (pharmacotherapy for cancer), others are cytotoxic chemotherapy and biotherapeutics. This involves the manipulation of the endocrine system through the administration of exogenous hormones or external hormones, especially steroid hormones, or drugs that inhibit the production or activity of the hormone (antagonistic hormone). Because steroid hormones are powerful movers of gene expression in certain cancer cells, altering the level or activity of certain hormones can cause certain cancers to stop growing, or even experience cell death. Surgical removal of endocrine organ, such as orchiektomi and oophorectomy can also be used as a form of hormonal therapy.
Hormonal therapy is used for some cancers derived from hormonal responsive tissues, including breast, prostate, endometrium, and adrenal cortex. Hormonal therapy may also be used in the treatment of paraneoplastic syndrome or to correct certain cancer-related and chemotherapy symptoms, such as anorexia. Perhaps the best known example of hormone therapy in oncology is the use of selective estrogen-response modulator for the treatment of breast cancer, although another class of hormonal agents, aromatase inhibitors, now has an increasingly widespread role. in the disease.
Video Hormonal therapy (oncology)
Inhibitor sintesis hormon
One effective strategy for tumor cells that starve from growth hormone and survival is to use drugs that inhibit the production of these hormones in their organs of origin.
Aromatase inhibitors
Aromatase inhibitors are an important class of drugs used for the treatment of breast cancer in postmenopausal women. At menopause, estrogen production in the ovaries stops, but other tissues continue to produce estrogen through the action of aromatase enzymes in androgens produced by the adrenal glands. When aromatase action is inhibited, estrogen levels in postmenopausal women may drop to very low levels, leading to the capture of growth and/or apoptosis of hormone responsive hormone cells.
Letrozole and anastrozole are aromatase inhibitors that have been shown to be superior to tamoxifen for the first-line treatment of breast cancer in postmenopausal women. Exemestane is an irreversible "aromatase inactivator, superior to megestrol acetate for the treatment of metastatic breast cancer that can cure osteoconosis, and appears to have no side effects that promote osteoporosis from other drugs in this class.
Aminoglutethimide inhibits both aromatase and other enzymes essential for the synthesis of steroid hormones in the adrenal gland. It was previously used for the treatment of breast cancer, but has since been supplanted by more selective aromatase inhibitors. It may also be used for the treatment of hyperadrenocortical syndrome, such as Cushing's syndrome and hyperaldosteronism in adrenocortical carcinoma.
Analog GnRH
Gonadotropin-releasing hormone analogues (GnRH) can be used to induce chemical castration, ie, complete suppression of estrogen and progesterone production from a woman's ovaries, or complete suppression of testosterone production from male testes. This is due to the negative feedback effect of the persistent stimulation of the pituitary gland by these hormones. Leuprorelin and goserelin are GnRH analogues used primarily for the treatment of hormone-responsive prostate cancer. Because the initial endocrine response to analog GnRH is actually gonadal steroid hypersecretion, hormone receptor antagonists such as flutamide are commonly used to prevent a temporary increase in tumor growth.
Maps Hormonal therapy (oncology)
Hormone receptor antagonist
The hormone receptor antagonists bind to normal receptors for given hormones and prevent activation. The target receptor may be on the cell surface, as in the case of peptide and glycoprotein, or possibly intracellular hormones, as in the case of steroid hormone receptors.
Selective estrogen receptor modulators
Selective estrogen receptor modulators (SERMs) are an important class of hormonal therapy agents that act as antagonists of estrogen receptors and are used primarily for the treatment and chemoprevency of breast cancer. Some members of this family, such as tamoxifen, are actually partial agonists, which can actually increase estrogen receptor signaling in some tissues, such as the endometrium. Tamoxifen is currently the first-line treatment for almost all pre-menopausal women with hormone receptor positive breast cancer. Raloxifene is another partial agonist SERM that does not appear to promote endometrial cancer, and is used primarily for breast cancer chemoprevention in high-risk individuals, as well as to prevent osteoporosis. Toremifene and fulvestrant are SERM with little or no agonist activity, and are used for the treatment of metastatic breast cancer.
Antiandrogen
Antiandrogens are a class of drugs that bind and inhibit androgen receptors, blocking the growth and survival effects of testosterone on certain prostate cancers. Flutamide and bicalutamide are antiandrogens that are often used in the treatment of prostate cancer, either as long-term monotherapy, or within the first few weeks of GnRH analog therapy. (See also Androgen deprivation therapy)
Hormone supplement
While most of the strategies of hormonal therapy seek to block hormone signaling to cancer cells, there are instances where supplementation with a specific hormone agonist may have an inhibitory, cytotoxic, or even cytotoxic effect on tumor cells. Since many hormones can produce antagonism and inhibition of feedback of other hormone synthesis, there is significant overlap between this concept and those discussed above.
Progestogen
Progestin (progesterone-like drugs) such as megestrol acetate and medroxyprogesterone acetate have been used for the treatment of hormone-responsive breast cancer, endometrial cancer, and prostate cancer. Progestin is also used in the treatment of endometrial hyperplasia, a precursor for endometrial adenocarcinoma. The mechanism of action of these hormones is unclear, and may involve direct effects on tumor cells (suppression of estrogen receptor level, changes in hormone metabolism, direct cytotoxicity) and indirect endocrine effects (suppression of adrenal androgen estrogen production and estrone sulphate formation).
Androgen
Fluoxymesterone, an anabolic steroid (testosterone-like) drug, is sometimes used for the treatment of advanced breast cancer. The mechanism of this androgen anticancer effect on breast cancer is unclear, but may be analogous to progestin.
Estrogen
Diethylstilbestrol (DES) estrogen is sometimes used to treat prostate cancer through suppression of testosterone production. It was previously used in the treatment of breast cancer, but has been replaced by a more effective and less toxic agent. Estrace is an estrogen that was previously used for antiandrogen therapy for prostate cancer. Polyestradiol phosphate is a long estradiol derivative used as an intramuscular injection.
Somatostatin analog
Octreotide is an analogue of the somatostatin peptide hormone, which inhibits the production of growth hormone and many peptide hormones in the gastrointestinal system, including insulin, glucagon, pancreatic polypeptide, polypeptide hull inhibition, and gastrin.. Octreotide is used for suppression of the hormonal syndrome that accompanies some pancreatic islet cell tumors, including Zollinger-Ellison gastrinoma syndrome and chronic hypoglycemia insulinoma. It is also effective in suppression of carcinoid syndrome, caused by advanced or extra-gastrointestinal carcinoid tumors. Octreotide can also be used for the treatment of severe diarrhea caused by 5-fluorouracil chemotherapy or radiation therapy.
Non-medical hormone intervention
In addition to drug use to produce endocrine changes to tumor suppressors, the destruction of endocrine organs through surgery or radiation therapy is also possible. Surgical castration, or removal of the testes in men and ovaries in women, has been widely used in the past to treat hormone-responsive prostate cancer and breast cancer. However, this invasive method has been largely replaced by the use of GnRH agonists, and other forms of pharmacological castration.
There are still situations where surgical castration may be beneficial as in special cases for women with high-risk BRCA mutations.
Hormonal Immunotherapy
For more information on this topic, see Immunotherapy
Hormonal stimulation of the immune system with interferon and cytokines has been used to treat certain cancers, including renal cell carcinoma and melanoma.
See also
- List of hormonal hormone-producing antineoplastic agents
References
Source of the article : Wikipedia
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