I am on Letrozole for breast cancer, it seem that now my thyroid is playing up, before my thyroid was functioning properly. Has anyone had thyroid problems after starting the letrozole?
I think there are some connections between Letrozole and thyroid issues. Possibly causing an underactive thyroid action, or bringing out previously unfound thyroid issues ?
I'm not 100% sure of any of this, however Helen is well up on thyroid problems. I'm uncertain if she is still out of the country on holiday or not, so she may not be able to reply for a while.
My oncolo told me yesterday that my last blood test (three weeks ago) has shown some problems with my thyroid, and it was borderline. I can't remember exactly what it was but she seemed to blame pembrolizumab (which I take for my lung cancer), and, as I started taking Letrozole one week before that particular blood test, I am trying to find out whether it would be possible that letrozole was the culprit of the sudden problem.
I had another blood test yesterday, and the nurse today told me that my thyroid was back to normal.
As I am taking 2 chemos, I wonder how they will be able to assess which one will be responsible when a problem will be arising.
I do not like the principle of cutting the oestrogen in a body, with all the problems that arises because of it, and took a big dislike about taking letrozole.
They eventually want to do a lumpectomy followed by radiotherapy. As I do not want any radiotherapy on the side of the heart (left breast), I am considering a mastectomy without radiotherapy (even thinking off a double mastectomy, as I don't want to worry about getting another lump in the right breast). I am just wondering about the pain involved and how long it takes to "recover" enough to go back to work after the operation.
Taking Keytruda / pembrolizumab has been shown to cause some people thyroiditis, and is a listed uncommon side effect - so knowing this pushes the cause more towards that than the letrozole but doesn't let it completely off the hook.
I can see your conundrum trying to figure out which one the culprit could be. I struggled to find some worthwhile information about this within the UK as most just mention thyroiditis without going into very much detail.
Jackie had a left mastectomy and 15 x rads. The chances of the heart being affected is very low, with a slightly higher chance of them clipping a lung instead but this seemed to pass off without any long term issues (May 2012) Totally understand your concerns with oestrogen depletion it is surprising how much benefit the body gets from oestrogen. Having said that J was strongly triple positive ER/PR and HER2 so Letrozole plays a big part in her avoiding the risk of recurrence or secondaries.
As far as recovering from surgery goes. A lot depends on the surgery and if any reconstruction(s) are included. Also any impact from an axillary node clearance (should that be offered) following the sentinel node biopsy. Straight forward mastectomies carry an advisory minimum 3 preferably 6 weeks before driving post surgery and this can hamper returning to work decisions.
Are you having any thyroid symptoms? It's probably difficult to tell what with the Letrozole as well. Here is a list of 300 long and pathetic symptoms which you may or may not have had prior to the Letrozole.
When your consultant says you are borderline, this can mean a number of things. Normal TSH ranges are something like 0.4-4.5 or 0.2-5.5. However the British Thyroid Association does not recommend treatment until the TSH reaches 10. (this is criminal but a whole nother story!). So does he mean you are 4/4.5/5 ish, or does he mean 9? Now the next thing I am going to say is incredibly important. ALWAYS get copies of your test results. You are entitled to them, it is your body. Secondly, NEVER pay any attention to the TSH once you have a diagnosis! Just for shiz and giggles, watch this YouTube video which explains why ... video link here.
Ask your consultant to arrange a full thryoid panel, including TSH, Free T4, Free T3, Thyroid Antibodies (Thyroid perioxidase and thyroglobulin), along with ferritin, b12, Vit D and folate. These need to be high in range in order to properly synthesize levothyroxine.
I've sent you a friend request, since this isn't really cancer related, and I am happy to chat more on PM if you like.
PS I'm back ... :) You're gonna love this video ... ^^^
Hi, my experience is quite different to yours, but thought I'd tell you. The blood test I had to check whether I had gone through the menopause BEFORE I started my hormone therapy showed that my TSH was low. I was advised to have it repeated 6weeks later, which I did. I had been taking anastrozole for 5 weeks or so when I had the second blood test and it showed that my TSH was back within normal limits! So my GP was certain that I did not need any TSH medication. Not sure if this is of any help or not.
Low TSH =underactive thyroid; High TSH = overactive. Both conditions are cause for concern and need to be treated and monitored. I'm sure the doctor is aware of which condition is which mistymoley.
If the level of thyroxine in the blood is high then the pituitary gland releases less TSH. Therefore, a low level of TSH means that your thyroid gland is overactive and is making too much thyroxine. Thyroxine (T4). A high level of T4 confirms hyperthyroidism.
I'm not saying they are confused, I'm saying that you may have misinterpreted what they said, but they may have explained it poorly.
I am aware they are both cause of concern, I am hypothyroid and have been for 24 years.
I suggest you ask for a copy of your blood results, since doctors often misinterpret these results.
