Hi Ladies
It may be a daft question but when we are on Letrozole for long periods do we have blood tests to determine our oestrogen levels? I just wondered because if we are ER+ how do we know if our oestrogen has lowered enough with the hormone therapy or not.
Just a random thought (I’m full of them:smileylol:), surely if the levels go too low we are at risk of all sorts of things and if it’s still high, well we all know what we are at risk of there.
Joemic x
I just started a few weeks ago nine years and 48 weeks … to go . No mention of blood tests I suppose monitoring us is enough . TBH had more than enough blood tests in past nine months !
Hello Joemic,
Not a daft question at all but a very logical one. Hopefully someone with more knowledge can give a more informed response to it. Perhaps you might like to post your question in the Nurses section.
My understanding is that there is no specific horrmone called oestrogen but there are 3 different main forms. Estradiol which is produced in the ovaries so I assume it is the pre menopausal dominant form, estriol which is dominant during pregnancy and estrone which is created from organs/fat tissue. and hence I assume is the post menopausal dominant form created from the action of aromatase on androgens/testosterone.
As far as I know, it is not as simple to measure estrone levels as it is, for example, to measure blood sugar levels. Just like when they do the test for whether someone has hit menopause, they don’t do a direct measure of estradiol levels but measure the. level of follicle stimulating hormone (FSH) in the blood. Even such results as theses can yield false negatives and positives.
I also heard that any blood levels of oestrogens can fluctuate greatly rendering any given measurement relatively uninformative. However perhaps someone should tell the bodybuilders who use aromatase inhibitors as they don’t seem to have a problem testing their blood levels.
I was told that measuring would have little purpose as no safe level has been determined/the level it takes to feed a tumour to life. But surely it would be useful to know whether the hormone meds are having a lowering effect, especially if people are not experiencing too many side effects and are debating efficacy of medication based on that! You would also think testing could alert people to drug resistance etc. at an early stage.
Whether using tamoxifen to block action of circulating oestrogen or aromatase inhibitors like Letrozole to inhibit the production of aromatase and stop the conversion to estrone, I think the aim is to reduce the action of oestrogen to zilch. I think aromatase inhibitors have been shown to reduce levels by over 95% . I don’t think there is a recognised unsafe low level, apart from when people have had enough of debilitating side effects and how much this is affecting their quality of life. Yes you are right that we can be at increased risk of other things from oestrogen depletion, for example, osteoporosis, increased cholesterol, effects on mental health. In the end we just have to make the best informed choice for ourselves. There are no guarantees with any treatments.
Regards,
Chick ? x