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UA_Iron
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I've posted like 2-3 threads regarding formestane, not one got the number of responses that this one did.
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Finally! A Progesterone Inhibitor!
- Thread starter Makavelli
- Start date
A
Anthony Roberts
Guest
Letrozole: Use it to eliminate progesterone (receptors) !
It's weird that Letro isn't known as an anti-progestin:
Pathological features of breast cancer response following neoadjuvant treatment with either letrozole or tamoxifen.
Miller WR, Dixon JM, Macfarlane L, Cameron D, Anderson TJ.
Department of Oncology, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK. [email protected]
Morphological characteristics, grading features, proliferation marker MIB1, apoptosis (by Tdt-mediated duTP-biotin nick-end labelling (TUNEL)), Bcl-2 expression, oestrogen receptor (ER) and progesterone receptor (PgR) status were compared in ER-positive breast cancers before and after 3 months of neoadjuvant therapy with either letrozole or tamoxifen. Daily treatment was with letrozole 2.5 mg (12 patients) or 10 mg (12 patients), or with tamoxifen 20 mg(24 patients). Letrozole treatment was associated with a pathological response in 17 of 24 (71%) patients. The predominant change in grading features was a decrease in mitosis, and the expression of MIB1 was reduced in all of the 22 evaluable cases. Whilst only marginal changes were observed in ER expression following letrozole therapy, PgR reactivity was reduced in 20 of 21 evaluable cases which were initially PgR-positive, becoming undetectable in 16 patients. Tamoxifen treatment was associated with pathological response in 15 of 24 (63%) tumours. In contrast to letrozole, the dominant change in grading feature was an increase in tubule formation, ER score was markedly reduced in most cases, and the most common effect on PgR was an increased expression. Following treatment with either tamoxifen or letrozole, variable effects were observed on the apoptotic index and expression of Bcl-2. These results indicate that both letrozole and tamoxifen have marked influences on the pathological features of breast cancer during neoadjuvant therapy. However, the effects of the two agents varied such that the phenotypes of letrozole- and tamoxifen-treated tumours differ markedly. Effects on clinical, pathological and biological endpoints were frequently disconcordant--future studies will therefore require the evaluation of multiple parameters in order to fully assess tumour response.
PMID: 12751376 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
Cancer Res. 1995 Jul 15;55(14):3073-7. Related Articles, Links
Effect of aromatase inhibitors on growth of mammary tumors in a nude mouse model.
Yue W, Wang J, Savinov A, Brodie A.
Department of Pharmacology and Experimental Therapeutics, School of Medicine, University of Maryland, Baltimore 21201, USA.
The effects of aromatase inhibitors 4-hydroxyandrostenedione (4-OHA), CGS 16949A, and CGS 20267 [letrozole], and of the antiestrogen tamoxifen (TAM), were studied on the growth of human breast carcinoma in a nude mouse model. To simulate the postmenopausal breast cancer patient, tumors were formed from inoculates of MCF-7 cells transfected with the human aromatase gene to provide a source of non-ovarian estrogen in ovariectomized mice. Tumor growth was significantly inhibited by all treatments (P < 0.05). Greater reduction in growth occurred in mice treated with TAM combined with aromatase inhibitors than with TAM alone. Tumor progesterone receptor concentrations were unaltered by TAM treatment but were reduced by aromatase inhibitors. Progesterone receptor concentrations correlated with tumor growth. The greatest reduction occurred in tumors of CGS 20267[letrozole]-treated mice in which no progesterone receptors were detected. In the ovariectomized mice used in these studies, uterine weight was maintained by estrogen produced from the tumor. Uterine weight was reduced by aromatase inhibitors but not by TAM treatment. However, there was a significant increase in uterine weight in mice treated with the combination of TAM and 4-OHA. Thus, the agonist effect of TAM was evident when estrogen synthesis was inhibited. The results indicate that aromatase inhibitors have potent effects on mammary tumor growth but lack the estrogenic effects on the uterus observed with TAM. There appeared to be no significant benefit in combining TAM with 4-OHA over 4-OHA treatment alone.
PMID: 7606729 [PubMed - indexed for MEDLINE]
I'm doing a bunch of research for the people at AG-Guys.com, because they are interested in furthering the use of their products, not just selling them, and have found novel uses for alot of anti-estrogens (letrozole as an anti-progesteron, etc....).
It's weird that Letro isn't known as an anti-progestin:
Pathological features of breast cancer response following neoadjuvant treatment with either letrozole or tamoxifen.
Miller WR, Dixon JM, Macfarlane L, Cameron D, Anderson TJ.
Department of Oncology, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK. [email protected]
Morphological characteristics, grading features, proliferation marker MIB1, apoptosis (by Tdt-mediated duTP-biotin nick-end labelling (TUNEL)), Bcl-2 expression, oestrogen receptor (ER) and progesterone receptor (PgR) status were compared in ER-positive breast cancers before and after 3 months of neoadjuvant therapy with either letrozole or tamoxifen. Daily treatment was with letrozole 2.5 mg (12 patients) or 10 mg (12 patients), or with tamoxifen 20 mg(24 patients). Letrozole treatment was associated with a pathological response in 17 of 24 (71%) patients. The predominant change in grading features was a decrease in mitosis, and the expression of MIB1 was reduced in all of the 22 evaluable cases. Whilst only marginal changes were observed in ER expression following letrozole therapy, PgR reactivity was reduced in 20 of 21 evaluable cases which were initially PgR-positive, becoming undetectable in 16 patients. Tamoxifen treatment was associated with pathological response in 15 of 24 (63%) tumours. In contrast to letrozole, the dominant change in grading feature was an increase in tubule formation, ER score was markedly reduced in most cases, and the most common effect on PgR was an increased expression. Following treatment with either tamoxifen or letrozole, variable effects were observed on the apoptotic index and expression of Bcl-2. These results indicate that both letrozole and tamoxifen have marked influences on the pathological features of breast cancer during neoadjuvant therapy. However, the effects of the two agents varied such that the phenotypes of letrozole- and tamoxifen-treated tumours differ markedly. Effects on clinical, pathological and biological endpoints were frequently disconcordant--future studies will therefore require the evaluation of multiple parameters in order to fully assess tumour response.
PMID: 12751376 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
Cancer Res. 1995 Jul 15;55(14):3073-7. Related Articles, Links
Effect of aromatase inhibitors on growth of mammary tumors in a nude mouse model.
Yue W, Wang J, Savinov A, Brodie A.
Department of Pharmacology and Experimental Therapeutics, School of Medicine, University of Maryland, Baltimore 21201, USA.
The effects of aromatase inhibitors 4-hydroxyandrostenedione (4-OHA), CGS 16949A, and CGS 20267 [letrozole], and of the antiestrogen tamoxifen (TAM), were studied on the growth of human breast carcinoma in a nude mouse model. To simulate the postmenopausal breast cancer patient, tumors were formed from inoculates of MCF-7 cells transfected with the human aromatase gene to provide a source of non-ovarian estrogen in ovariectomized mice. Tumor growth was significantly inhibited by all treatments (P < 0.05). Greater reduction in growth occurred in mice treated with TAM combined with aromatase inhibitors than with TAM alone. Tumor progesterone receptor concentrations were unaltered by TAM treatment but were reduced by aromatase inhibitors. Progesterone receptor concentrations correlated with tumor growth. The greatest reduction occurred in tumors of CGS 20267[letrozole]-treated mice in which no progesterone receptors were detected. In the ovariectomized mice used in these studies, uterine weight was maintained by estrogen produced from the tumor. Uterine weight was reduced by aromatase inhibitors but not by TAM treatment. However, there was a significant increase in uterine weight in mice treated with the combination of TAM and 4-OHA. Thus, the agonist effect of TAM was evident when estrogen synthesis was inhibited. The results indicate that aromatase inhibitors have potent effects on mammary tumor growth but lack the estrogenic effects on the uterus observed with TAM. There appeared to be no significant benefit in combining TAM with 4-OHA over 4-OHA treatment alone.
PMID: 7606729 [PubMed - indexed for MEDLINE]
I'm doing a bunch of research for the people at AG-Guys.com, because they are interested in furthering the use of their products, not just selling them, and have found novel uses for alot of anti-estrogens (letrozole as an anti-progesteron, etc....).
A
Anthony Roberts
Guest
Makavelli said:
I'll have more relevant studies to post when I get home. I'm in the Carribean right now, and have limited internet access...
You all suck. I am really pissed because I mentioned this Formestane a couple of times over the past year. And guess what? No one was interested.
The funny thing is that you could get it from HM Gear over the counter before the ban on prohormones. Smart people knew this and loaded up.
So screw you guys I'm going home!
The funny thing is that you could get it from HM Gear over the counter before the ban on prohormones. Smart people knew this and loaded up.
So screw you guys I'm going home!
U
UA_Iron
Guest
vitamix said:
you can get it from the link I posted on this thread...which everyone overlooked.
U
UA_Iron
Guest
Sorry Macro, I know that site's band from EF.
