Thyroidectomy and metastasic breast cancer

pinkPink65

Hello guys,

my mom was first diagnosed with breast cancer almost 5 years ago and about 7 months ago we found out that the cancer had come back and had spread to her liver.

She is taking Zadolex, Ibrance and Letrozol. At the beginning everything was fine but around two months ago she started feeling really badly every now and then. Every couple of weeks she had three days with strong headaches and vomits.

We went to the doctor many times but they did not find anything. We then finally found out that my mom had high blood pressure (which we thought it was a side effect of letrozol) and started taking medication to control it.

Even though she took this medication, she kept having these days in which she had headaches and vomits and her blood pressure would increase very quickly and keep going up and down the whole day. At that point we did not know what to do, until it occurred to us that they had not checked her thyroxine levels since she was first diagnosed with metastasic breast cancer, so we went again to the doctor to have that checked. And surprise, surprise the thyroxine levels were too high. So she stopped taking thyroxine for a few days and now she has started with a lower dosis.

We were just wondering if there is anyone here that has had a similar problem and could tell how they fixed it. Since she has just started with the new dosis and it takes a while for the body to adapt to this new one, we do not know if this is actually the cause of everything.

Thank you in advance

Yogatyme

I had bmx in Aug and was on estrogen replacement until my bc dx. I stopped it immediately. I have been hypothyroid for many years and after stopping Premarin, I began having terrible sweats, pounding, racing heart, headache. Long story short it was my thyroid and not recovery from bmx. Once my thyroid was regulated again I was fine.

pinkPink65

Thanks for your reply yogatyme!

Im glad it worked out.

How much time did it go by from the moment you started on the meds until your thyroid was regulated?

It seems though that you did not have any vomits? Did you have high blood pressure?

My only problem is that I do not know if this is the only cause for her symptoms. On Wednesday she started having strong headaches again but thankfully on Thursday she was fine again.

Our problem is that her doctors do not investigate anything and just assume everything she has is just a side effect of Letrozol. Which is why they did not check her thyroxine levels and also did not check her blood pressure (until we found out about it on our own) assuming it was just headaches due to Letrozol (even though high blood pressure is a common side effect as well!).

Yogatyme

pink, my blood pressure was also irregular but has been fine since change in Synthroid dosage. It is hard to say how long it took to regulate thyroid b/c I was also recovering from bmx, but I would say about 2 weeks. I hope your mom gets to feeling better soon

pinkPink65

Thank you so much for your insight!

choochoobella

Hi pinkPink65,

I'm so sorry your mom hasn't been feeling well.

I don't have metastatic breast cancer, but I wanted to respond to your questions regarding Letrozole (I've had stage 4 thyroid cancer and stage 1 breast cancer). So your mom was on too much Letrozole which made her hyperthyroid for a while. I've been on thyroid replacement hormone for 25 years and have had periods of both hypothyroidism and hyperthyroidism during that time, so my medication has been adjusted accordingly at those times.

One thing that might seem strange is that your TSH levels can change over time even though you have been on the same dose of Letrozole. I don't know why that is. At least it's true for me. My sister, on the other hand, had thyroid cancer and a thyroidectomy 8 years ago and has been on the same dose of Letrozole all this time and her TSH levels have remained constant.

When you are hyperthyroid, as your mom was, as evidenced by too high a thyroxine level, you usually get symptoms like a pounding heartbeat, restlessness, feeling anxious, sweating, trouble sleeping, feeling shaky, etc. At least that's how I've felt whenever my TSH levels were out-of-whack and I was hyperthyroid.

When the Letrozole dose is lowered to address being hyperthyroid, it takes approximately 6 to 8 weeks before the doctor runs a new TSH level to see if you are no longer hyperthyroid. It's kind of tedious to adjust Letrozole levels because you have to wait 6 to 8 weeks to get a full response to the altered dose of Letrozole. Usually, my doctor will run a TSH level (she will sometimes also run T3 and T4 levels) after 6 to 8 weeks at the new dose. If the TSH level still isn't in the right range, she will adjust the dose and test again in another 6 to 8 weeks.

Just to be clear, there are 3 tests your mom's doctor might have run on her thyroid (TSH, T3 and T4). I'm guessing her doctor might have run all 3 tests. If the doctor said her thyroxine level was too high, that shows up in the T4 test. The most common test to run to check thyroid function is the TSH.

Now back to your original comment about your mom's symptoms of headache and vomiting, I don't associate those symptoms with screwy thyroid levels. If anything, those symptoms sound like they could be related to your mom's high blood pressure. Has your mom's doctor been checking your mom's blood pressure regularly to see if it is normal? Bad headaches are often related to high blood pressure. The vomiting, I'm not sure about. I don't think of that as being related to her thyroid or blood pressure issues. but I'm no doctor.

I'd want her doctor to be checking her blood pressure regularly to make sure it is in the normal range. As I said, her doctor probably won't check her thyroid levels again until 6 to 8 weeks have passed on the lowered dose.

I sure hope she is feeling better. Bad headaches and vomiting are so distressing.

All the best to you and your mom,

Julie

jensgotthis

I spoke with a Pfizer pharmacologist about the warning that Ibrance can increase the effects of other medications. I experienced this with my synthroid dose and ended up having to lower it since I was in a hyperthyroid state after starting the Ibrance