Thyroid UK
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Anyone have any info in relation to breast cancer and hypothyroidism?

I had breast cancer 10 years ago and although I had a good prognosis, I have now found something else suspicious and am returning to hospital tomorrow to get this assessed, keeping everything crossed that it is ok. However it has made me wonder that if the symptoms of hypothyroidism have potentially affected this. All the no no's that hospital state you need to do to keep healthy after cancer have been tuned upside down ie have never weighed so much ever; am too fatigued and dizzy to undertake exercise. Just makes me wonder what is happening at a cellular level... ( I have almost every symptom but negative bloods)

7 Replies

Sorry to hear you dealing with so much at the moment. It could be that your treatment 10 years ago had a negative impact on your thyroid. It happened to a friend of mine. Do you have copies of your most recent blood tests - with ranges. Maybe they are not quite as normal as you have been told :-)

How are your levels of B12 - Ferritin - Folate - Iron - VitD ? They all need to be OPTIMAL for you to feel well....

Hope all goes well....


Stress is a no no - and being ill is stressful. I found meditation useful (restful and easy to do, as well). Vit D is important for breast cancer so get that checked if you haven't. I also went gluten and meat and dairy free (to avoid artificial hormones in meat and dairy - all organic would be OK).


There is absolute correlation between estrogen dominance (progesterone deficiency) and hypothyroidism. Too much estrogen not only causes the estrogen-driven cancers (breast, uterine, ovarian, testicular, prostate, etc), it also inhibits thyroid function at the cellular level. Cortisol from too much stress also has this effect. Additionally, under chronic stress and trauma (make no mistake, going through breast cancer is traumatic!), cortisol depletes progesterone, as it's actually "stolen" in order to make more cortisol. All this can be happening, and what a person has is cellular hypothyroidism, while all the labs show thyroid function as "normal" and doctors completely overlook it. I'd suggest seeing a functional doctor who understands how these relationships all work, in the hormone structures.

Bottom line: You need to know what's going on with your estrogen and progesterone levels. You need to know what's going on with your cortisol levels. How's your body temperature? Because if your body temperature is consistently low, then you are definitely having a thyroid problem on some level, and I'd bet it has to do with estrogen dominance and out-of-control cortisol levels preventing thyroid function at the cellular level. AKA cellular hypothyroidism.

Another thing to note is that unopposed estrogen makes us gain weight. Not only by expanding our fat cells, but also actually creating even more fat cells. Estrogen is also inflammatory in many cases. Now - add to the mix - fat and thyroid: the fatter we get, the less our thyroid hormones work, and the less our thyroid hormones, work, the fatter we get. More inflammation - fat cells are actually inflammatory. Now when our inflammation goes up, our immune systems get turned on, and now we're in position to start experiencing all sorts of inflammation-caused conditions, like Hashimotos and cancers and diabetes and other autoimmune disorders. All because nobody understood that 1. we didn't have enough progesterone, and 2. we didn't have adequate T3 levels. Sadly, most the doctors who we go to are either ignorant about how all this works, or they're part of a conspiracy to keep us sick so that the entire industry keeps making more and more money off our suffering. I mean, neither progesterone nor T3 is particularly profit-worthy...

Here's some additional reading for you, if you'd like to know more from the experts who know this stuff:

I hope that you feel better and get all the very best help and everything you need.

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Iodine is essential for breast health. Do read Dr. David Brownstein's book " Iodine why we need it and why we can't live without it".

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Well said 1133, 100% agree with everything you have written.


Thank you everyone for your replies much appreciated. Went to hospital for a long time today but emerged knowing that my cancer has not returned which is brilliant news! Now just to tackle the hypothyroidism which is another issue in itself!

As my initial cancer wa s maximum reliant on both progesterone and oestrogen I was put into menopause 10 years ago.

My GP is not particularly experienced and one of the other partners has long standing ideas that he has not updated. I wrote an explicit letter when I went to my Gp a few weeks ago requesting certain blood tests (most refused). I outlined family history ie four members of my family who have hypothyroidism and my basal temps which varied from 34.2 to 35.4..... which again there was little positive response to.

Thank you 1133 for taking the time to write a long post. I am a nurse but am the first to say that my knowledge around thyroid issues was limited but as your post suggested my thoughts were cellular hypothyroidism.....something ignored by GP. however one of the docs today suggested this to me as well ....I will be pursing this as soon as I have had bloods taken and results (am having this privately.

My GP has taken VIT D which came back at 59 (adequate she would say) however with my cancer history I was told this should be between 100-150 so its way down. I have been taking a supplement of 4000mg for over a year with no increase (previously 54) .

Iron is 14.5 Gp was supposed to do Ferritin but no result was found for that!

Thank you , its great to know that support can be received a t a touch of a button!!


I read in Dr Peatfeilds book that iodine is thought to prevent breast cancer. Also needed for thyroid function but can I have also heard make hypothyroidism worse.


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