AI's & blood tests to monitor oestrogen levels

Hey - I have, maybe naively, thought that with ovary suppression and AI, the levels of oestrogen should be low if not non existent...where else can oestrogen be made apart from ovaries and converted from androgen? It certainly feels like all mine has been taken away....I creak like a 90 year old...! 

Will follow with interest - I have been on this combo since January.

Hi, I have been on Letrozole for 4 years and have read shed loads about it.

The tablets are 2.5mg, the research by the original makers show that a dose of 0.5mg achieves the same as 2.5mg and there is a maximum reduction in Oestrogen of 78%. So I suppose no reason or need to check our hormone levels.

Think maybe you will be able to tell in quite a few ways that your hormone levels have dropped. xxx

I wonder if there is a blood test to show the levels of oestrogen in our body/blood.

This would be brilliant - mind you, I think we would be the ones more interested than the oncologist etc.  

I have read and I’ve been led to believe (rightly or wrongly) that, get this .... arrghh oestrogen can and is made in ‘fat cells’ hence why they recommend overweight people to loose weight - less fat cells, this then lowers the eostogrn levels  

I’d welcome any thoughts or differences with this regard.

sebd love to all xxx

Hi WhatHappened,

There is indeed a blood test to measure our Oestrogen levels but apparently, it is not straight forward, I asked the question and that's all I was told, I might ask again as its something I've thought of a few times since being on Femara. 

Oestrogen is produced in the fat cells as we get older, ie menopausal and beyond, BC Nurse said! 

It is an interesting discussion, hope someone comes along and provides us with more info. 

Best Wishes.

hi snowys mum,

Your post was really interesting....but why are we on 2.5 if 0.5 would do the trick. Is that official?

Only asking because , for the very first time on this site I am feeling down. No boring details, but have had most of the nasties life throws at us and always managed to "never give in"  "keep going" etc ...BUT for the first time this Letrozole drug is depressing me. I don't feel I can talk to my GP I haven't had much luck researching whether the cheaper versions are bad, have lost energy, my hands have gone clawlike and painful,At times when I have had a hard day  I shuffle like a 90 year old, and this isn't me. Tomorrow I may bounce back again, I usually do,.. just having a blip..sorry...but I could handle it better if I knew that Femera would be easier to absorb..(.I would try to pay privately) : if I felt that they were "all the same" as doctors say,:  if it was just each person reacts differently..: if it really does its' job...I would love to come off it for a month and see if I got "myself" back.

Sorry ladies..has anyone else had this blip.? Anyone else any up to date research ? Perhaps we would all cope better if the experts would give up more information about the drug. a few statistics would help. Thank you SnowysMum for an interesting post. God bless to all. 

Hi calador

I came off for 4 weeks  (with bcn agreement) for other reasons than yours - see profile.  No one was too worried about a short break.  Why not ring your bcn?

And do hope you feel better soon xx

I'd be interested in the dose details too, as very sensitive to most meds. and if half a tablet would work just as well would consider that.

 I asked the question because I personally feel 10 years is a long time to be on any drug with absolutely no monitoring of its action. If you are post menopausal or made post menopausal by zoladex like me then your ovaries no longer produce hormones and oestrogen is only made locally in bones, brain, vascular tissue and fatty tissue and it's made by conversion involving aromatase. There are blood tests that measure circulating oestrogen ( so called free oestrogen) but I'm wondering if those blood tests for oestrogen levels can accurately reflect local oestrogen synthesis in the body? And if anyone was to take a lower dose of this drug surely you'd need to measure oestrogen suppression levels? 

If you read the summary of product online it does say oestrogen suppression is 78% but in a research study from 2016 comparing doses and frequency the 2.5 mg daily dose did come out as slightly more effective at suppressing Estrone levels (93%) compared with Mon/Wed/Fri doses. But I do wonder too if 2.5mg is excessive especially as the half life of the drug is so long in the body (2 days at least). I wish there were more studies out there comparing doses. What was interesting about the 2016 study though was that the side effects didn't seem to be better on a lower dose. Is anyone on here taking a lower dose and finding side effects better?

I'm due to see my oncologist in September so I will ask about blood testing and its limits.

I seem to remember reading that someone on the forum took half a tablet a day but don't remember who.

Wowwww ladies, don't you just love these posts.   Look at all of us, its like we are studying for our degree's.  Mind you, I reckon between us the knowledge of information we have to offer is immense, if they only would listen to us.

I to have heard about the dosage, I did even wonder if the tablet was cut in half, and have half one day and half the next - then knowing the original tablet contains 2.5 then we would know ever two days we are have more than the recommended dose.  I asked my oncologist, I didn't quite take the reply in as I had built myself up to ask the question - it was something like, well why take less when they say this amount is what is needed.... or something along those lines.

Here is a link that is worth reading.... it is a little overwhelming, but, if you look at sections slowly - you can take in a fair bit of information and if you are like me; you'll forget it as quick as you read it.

The part that I have found that seems to relate to dosages, is relating to 'advance bc'. it is in the first paragraph of section 12.2

https://www.pharma.us.novartis.com/sites/www.pharma.us.novartis.com/files/Femara.pdf

This goes without saying, however, I am saying it to make sure we are all sure... I am 'not' recommending anyone changes any treatments, this is for you to read and gain information only. 

You then have additional information that you can look through and ask your own Doctor, Consultant, Oncologist if you have any questions.

Looking forward to hearing anyone else's thoughts on all of this.

Love to all xxxx