djbombsquad
Board Sponsor
What is the difference? I have tamoxifen and looking to get some letrozole.
Letrozole vs tamoxifen
- Thread starter djbombsquad
- Start date
strategicmove
Legend
djbombsquad; said:
This might help:
Study Confirms Letrozole Better than Tamoxifen
Likely a Better Option for Advanced Breast Cancer
Article date: 2003/06/17
Tamoxifen has been the standard form of hormonal therapy used to treat advanced breast cancer for more than two decades. But newer drugs called aromatase inhibitors are proving to be just as good, if not better than, tamoxifen.
New study results reported in the Journal of Clinical Oncology (Vol. 21, No. 11: 2101-2109) now confirm the superiority of one of these drugs, letrozole (Femara), over tamoxifen in cancer that is locally advanced or has spread to other parts of the body.
Breast Cancer and Hormones
Most breast cancers grow in response to levels of estrogen in the body. Estrogen is a �female� hormone that signals breast cells to grow by attaching to specific proteins called receptors on their outer surfaces. Tamoxifen, which first came into use in the 1970s, works by blocking these estrogen receptors, preventing estrogen from attaching to them. It has proven to be effective in prolonging survival in women with advanced breast cancer who have many estrogen receptors on their cells. (These cancers are considered to be �estrogen receptor positive.�) In almost all women with advanced cancer, however, tamoxifen eventually stops working.
Scientists developed aromatase inhibitors to help women with breast cancer for whom tamoxifen does not work or is no longer working. These drugs function by preventing estrogen from being produced in the first place, but they are only effective in women who are past menopause. (These women�s bodies are no longer producing large amounts of estrogen on their own.)
Three modern versions of aromatase inhibitors � letrozole (Femara), anastrozole (Arimidex), and exemestane (Aromasin) are FDA approved for use in breast cancer when tamoxifen is no longer effective.
Since these drugs worked so well in women no longer responding to tamoxifen, doctors wondered if they would be better than tamoxifen if used initially. Researchers attempted to answer this question regarding letrozole in the current study, begun in 1996.
Letrozole versus Tamoxifen
The newly published results are actually an update of study findings first published two years ago. This study was the key to the FDA approving letrozole for use as first-line therapy for advanced beast cancer in 2001.
In this multinational clinical trial, more than 900 postmenopausal women with advanced breast cancer were assigned to take a daily pill consisting either of tamoxifen or letrozole. None of the women knew which pill they were taking, but they could be crossed over (switched) to the other form of therapy if the initial one stopped working. The average time on the study for these women was 32 months.
The women taking letrozole were more likely to have their tumors shrink by at least half than those taking tamoxifen (32% vs. 21%), and were more likely to have at least some period of time when the cancer did not grow (50% vs. 38%).
Those taking letrozole also had a longer average period of time before the cancer progressed (9.4 months vs. 6 months) and were able to take the hormonal therapy longer (16.3 months vs. 9.3 months). They had a longer period of time before the disease affected their everyday functioning, as well.
Women taking letrozole had a slightly longer average survival time (34 months vs. 30 months), but these numbers were close enough that the difference may have been due to chance. Fewer women on the letrozole arm appeared to die early (in the first two years of the study), however.
The researchers pointed out that while the survival difference was not statistically significant, it was likely influenced by the fact that about half the women on each study arm crossed over to the other form of therapy. This meant that about half of the women overall eventually received both letrozole and tamoxifen, which would tend to make the survival results similar for both arms.
Results Promising, But More Data Will Be Key
Overall, however, most of the study results still favored using letrozole over tamoxifen in this situation.
�The consistency of the results in this trial supports the use of letrozole as superior first-line [hormonal] therapy compared with tamoxifen in postmenopausal women with hormone-sensitive advanced breast cancer,� the authors conclude.
It is not clear whether the study will immediately change the way doctors treat their breast cancer patients, however. One reason for this is that there is more than two decades� worth of data backing tamoxifen use in advanced breast cancer, while the data supporting letrozole is only a few years old. Doctors may feel that more studies, exploring both the benefits and risks of the new drug, will be needed to cause a true change in practice.
Still, the results are promising, and may lead women and their doctors to consider letrozole as an effective option in treating advanced breast cancer.
ACS News Center stories are provided as a source of cancer-related news and are not intended to be used as press releases.
Irish Cannon
Legend
There's your answer.
djbombsquad
Board Sponsor
So tamo blocks new estro and letro shuts down existing estro? That is what I am getting at.
djbombsquad
Board Sponsor
I herd with letro you should only do it couple times during a 6 week cycle because it is that powerfull. Something like twice to three times a week at most.
djbombsquad
Board Sponsor
That is what I figured but was not 2 clear. Thanks.
LilPsychotic
Well-known member
This article addresses malignant tumors, not gyno/estrogen related effects from steroid use. The better of the two drugs depends on what your using it for. Both can be effective for our purposes if used properly.
LilPsychotic
Well-known member
Tamoxifen blocks estrogen at tissue specific sites (eg breasts), while letro enhibits the enzyme that converts test to estrogen. Letro is not for pct, but can be used on cycle to reduce estrogen related sides, or could be used treat gyno if it pops up after a cycle. Letro is extremely powerful, and needs to be used properly to avoid any estrogen up-surge after its discontinued. So, if you state your intended use for these drugs, someone may be able to help you out.
camaroguy18
New member
That sounds somewhat confusing...
Letro is not for PCT...yet it can be used to treat gyno if it pops up after a cycle.
So what you're saying is, alone, Letro is not a sufficient PCT coming off a cycle like a SERM is...but if one were to experience gyno after a cycle, throwing in some Letro (while on PCT, or after PCT) would be okay?
LilPsychotic
Well-known member
Well, I've seen guys use it for pct before because it does boost test levels by raising LH, FSH, and SHBG. The problem is that is erraticates your body of estrogen to undetectable levels, which is not a good thing. Small levels of est in the male body are nessesary for numerous things, not to mention the rebound effect from est. being this low. SERMS do not have this est. deleting effect...at all. They just block estrogen at the receptor, as your body works to restore a normal test to est ratio. Does this make sense?
camaroguy18
New member
yea it does...so if someone were to run Letro after PCT, they would almost need to followup with a small dose of a SERM to help combat estro rebound?
LilPsychotic
Well-known member
Exactly.
djbombsquad
Board Sponsor
What does should one do if letro for a 8 week cycle. I just got mine and I want to dose it very low just enough to kick start it but want to keep it low all 8 weeks.
djbombsquad
Board Sponsor
I am thinking
staying at .1mg every other day.
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0.02 mg of Letrozole increased testosterone by 45% after 2 days
0.1 mg of Letrozole increased testosterone by 49% after 2 days
0.5 mg of Letrozole increased testosterone by 48% after 2 days
1 mg of Letrozole increased testosterone by 41% after 2 days
2.5 mg of Letrozole increased testosterone by 74% after 3 days
10 mg of Letrozole increased testosterone by 97% after 2 days
30 mg of Letrozole increased testosterone by 113% after 3 days
staying at .1mg every other day.
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0.02 mg of Letrozole increased testosterone by 45% after 2 days
0.1 mg of Letrozole increased testosterone by 49% after 2 days
0.5 mg of Letrozole increased testosterone by 48% after 2 days
1 mg of Letrozole increased testosterone by 41% after 2 days
2.5 mg of Letrozole increased testosterone by 74% after 3 days
10 mg of Letrozole increased testosterone by 97% after 2 days
30 mg of Letrozole increased testosterone by 113% after 3 days
Irish Cannon
Legend
30mg of letro are you insane?
If you're looking to increase natural test levels, buy something like Advanced PCT and stack it with Activate.
djbombsquad
Board Sponsor
No I found the dosages on line doing my research and I am going to do .1mg. Maybe bring it at most to 1mg or 2.5 during mid cycle and taper it back down to .01 lol I would never do 30 hahaha. Plus I want one bottle to last me at least 3-6 months. 49% + powerfull has 53% increase so thats 102% increase in test. Not sure how much is free test that will be but still thats alot.
Formula94
Member
I wouldn't go past .5mg eod of letro. That much will eliminate nearly all the estro from your body. If you do 2.5mg of letro your joints are going to be worse than 90 year old arthritic patient and your libido will be non-existant. Towards the end of your cycle ramp the dose of letro down before starting nolva so that there is maybe a day or two of overlap to help prevent the rebounding effect.
jonny21
Registered User
Its only confusing if you do not really know what the reason for proper PCT. You are mistaken a common side effect, gyno, as the primary reason for use of a SERM for PCT. Gyno is the result of imbalanced hormone levels. Start with the SERM, if you have tell tale signs of the start of gyno i.e. itchy swollen nipples then add 1.25mg/letro EOD in conjuction with SERM.
The point is to restart endogenous Testosterone production a normalize hormone levels. That is why a SERM such as Nolvadex, Clomid, Toremifene... are used and then tapered down to prevent rebound estrogen elevations.
Using Letro to boost Test levels will not work in PCT since endogenous production has been decreased by exogenous supplementation, meaning that you have limited Test to free up or prevent from converting.