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Hormonal therapy of cancer
Hormonal therapy of cancer is one of an important modalities of medical treatment of cancer by using external or exogenous administration of special types of hormones such as steroid hormones which acts as hormonal antagonist it has been found that up to 15% of tumors may have responsive elements to hormonal therapy
Some tumors such as breast and prostate cancers ,originate from tissues whose growth is under hormonal control
The first attempts at
hormonal therapy were through surgical removal of an endocrine organ or ablation of the organ producing
the hormones of interest, such as oophorectomy for breast cancer
But nowadays hormonal manipulation is accomplished by several different modes
Hormones
or hormone like agents can be administered to inhibit tumor growth by the following methods
Blocking or antagonizing the naturally occurring substance, such as
estrogen antagonist tamoxifen
Aromatase
inhibitors, block the peripheral conversion of
endogenous, androgens to estrogen in postmenopausal women
Hormonal therapy provides a highly tumor-specific form of therapy in sensitive tissues
Hormonal therapy provides a highly tumor-specific form of therapy in sensitive tissues
In breast cancer, estrogen and progesterone receptor status is
used to predict the success of hormonal therapy
What are the hormonal Anticancer Agents
Androgens hormones
testosterone and fluoxymesterone in are used for treatment of advanced breast cancer
Antiandrogens hormones
Which acts by binding and inhibition of the androgen receptors
flutamide and finsaterids are used for treatment of prostate cancer
Antiestrogens hormones
Which it is one of the most important class of hormonal therapy which acts as antagonists of the estrogen receptors and are used mainly for treatment and chemo-prevention of breast cancer such as tamoxifen which it is mainly partially agonist which can increase estrogen receptor signals in some tissue such as the endometrium
tamoxifen is considered the first line of treatment in nearly all pre-menopausal women with hormone positive receptor breast cancer
Raloxifene is another partial agonist which can be used mainly as chemoprevention of breast cancer in high risk patient and also to prevent osteoporosis
Toremifene and fulverstrant are used may in metastatic breast cancer
Raloxifene is another partial agonist which can be used mainly as chemoprevention of breast cancer in high risk patient and also to prevent osteoporosis
Toremifene and fulverstrant are used may in metastatic breast cancer
Estrogens hormones
diethylstillbestrol DES is used for treatment of prostate cancer through suppression of testosterone production and ethinyl estradiol used for treatment of breast cancer
Glucocorticoids
hydrocortisone in leukaemia and lymphima
prednisone in breast cancer
dexamethasone in multiple myeloma
Gonadotropin inhibitors or GnRH analogs
Gonadotropin releasing hormones analogs can be used to produce chemical castration that is complete suppression and production of estrogen and progesterone from the female ovaries or complete suppression of testosterone production from the male testes this is due to negative feedback effect of continuous stimulation of pituitary gland by these hormones such as
Gonadotropin releasing hormones analogs can be used to produce chemical castration that is complete suppression and production of estrogen and progesterone from the female ovaries or complete suppression of testosterone production from the male testes this is due to negative feedback effect of continuous stimulation of pituitary gland by these hormones such as
leuprolide which used for treatment of prostatic cancer and gosereline acetate in breast cancer
Progestins hormones
hydroxyprogesterone caproate is used for treatment of endometrial cancer and medroxyprogesterone in breast cancer
Aromatase inhibitors
Aromatase inhibitors are an important class of drug used in treatment of breast cancer in post-menopausal women as it known at the age of menopause the estrogen production from the ovaries stopped but thee are other tissue such as adrenal gland which continuous to produce estrogen by the action of aromatase enzyme on androgen produced by adrenal gland so when the action of this aromatase enzyme is blocked this lead to decreased estrogen levels in post-menopausal women leading to arrest of growth of hormones response of cancer cells
These drugs such as
Letrozole and anastrozole are aromatase inhibitors which have been shown to be superior to tamoxifen for the first line of treatment of breast cancer in post-menopausal women
Aromatase inhibitors are an important class of drug used in treatment of breast cancer in post-menopausal women as it known at the age of menopause the estrogen production from the ovaries stopped but thee are other tissue such as adrenal gland which continuous to produce estrogen by the action of aromatase enzyme on androgen produced by adrenal gland so when the action of this aromatase enzyme is blocked this lead to decreased estrogen levels in post-menopausal women leading to arrest of growth of hormones response of cancer cells
These drugs such as
Letrozole and anastrozole are aromatase inhibitors which have been shown to be superior to tamoxifen for the first line of treatment of breast cancer in post-menopausal women
aminoglutemthimide which inhibit both aromataze and other enzymes important for steroid hormones synthesis from the adrenal gland it is used for treatment breast cancer but it is replaced by more selective aromatase inhibitors also used in treatment of prostate cancer cushing syndrome
Somatostatin analogues
Octreotide is analog of the peptide hormone somatostatin which inhibit the production of the gorwth hormone and many peptide hormones of the gastrointestinal tract such as
Octreotide is analog of the peptide hormone somatostatin which inhibit the production of the gorwth hormone and many peptide hormones of the gastrointestinal tract such as
neuroendocrine tumors of the gut , carcinoid vipomA APUD tumors amine precursor update and decarboxlylation also can be used in treatment of severe diarrhea caused by 5-fluorouracil chemotherapy or radiation therapy
What are the indications of hormonal therapy
Prostate tumours
subcapsular orchidectomy bilateral antiandrogens LHRH analogues stilboestrol oestrogen
Breast tumours
tamoxifens :pre and post menopasual women if ER (Estrogen Receptor) negative or PR (Pregstrone Rceptor) positive
aromatase inhibitors prevent oestrogen production from peripheral fat no effect on ovarian oestrogen so post menopausal only recent evidence of superior survival in advanced disease compared with tamoxifen for 3rd generation aromatase inhibitors eg anastrazole
progestogens now tend to be used 3rd line as aromatase inhibitors are superior
LHRH analogues monthly goserelin in pre menopausal women 3 monthly preparation does not reliably suppress menstruation in all
Thyroid tumours
thyroxine to suppress TSH secretion
liothyronine used
Non medical hormonal therapy
The use of hormonal medications to suppress tumor activity by these hormonal drugs can be also done either through surgical removal of this endocrine organs or by radiation therapy such as surgical removal of the testes by operation called orchiodectomy or surgical castration in case of cancer prostate or surgical removal of the ovary by operation called oophroectomy in case of breast cancer but these invasive methods are replaced by using GnRH agonist and other forms of pharmacological castration but surgical castration may be benefit in special cases of female cancer with high risk BRCA mutations
tags:anticancer,hormonal,therapy,octreotide
Non medical hormonal therapy
The use of hormonal medications to suppress tumor activity by these hormonal drugs can be also done either through surgical removal of this endocrine organs or by radiation therapy such as surgical removal of the testes by operation called orchiodectomy or surgical castration in case of cancer prostate or surgical removal of the ovary by operation called oophroectomy in case of breast cancer but these invasive methods are replaced by using GnRH agonist and other forms of pharmacological castration but surgical castration may be benefit in special cases of female cancer with high risk BRCA mutations
tags:anticancer,hormonal,therapy,octreotide
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