Thyroid desease and breast cancer
 

Hi everyone,

I have heard that there may be a connection between thyroid deseases and breast cancer. I have read somewhere that thyroid hormones could promote breast cancer either by raising the metabolic rate or by cross talk with the ER pathway.

This thing really concerns me, because the last october my mother was diagnosed with a sublinical hyperthyroidism. During a routine control of the diabete her family practictioner found abnormal level of T3 and T4 and a low level of TSH. I wonder if there is a connection between her hyperthyroidism and her breast cancer recurrence because incidentally the two things occurret almost at the same time.

I know, all this is just speculation, but I can't help myself to do otherwise.

Anyone would like to chime in?

I just opened this thread to let you know that maybe thyroid as well should be taken into the picture.

Re: Thyroid desease and breast cancer
 

Hmmm...
I don't know if this confirms or negates the connection theory, but I have been hypo thyroid for 30 years.

Please give my best regards to your mother!
Denise

Re: Thyroid desease and breast cancer
 

Hi,
I had Graves Disease in 2000, took RAI (radioactive iodine), then went from hyperthyroidism to euthyroidism--when the thyroid is totally burned out. I am maintained for hypothyroidism with Synthroid.
Karen

Re: Thyroid desease and breast cancer
 

I was dx'd with hypothyroid, and borderline diabetes (both discovered through routine bloodwork) 2 years ago. Now on meds for thyroid, diet for diabetes, I need to check to see if any of this coincides with end of arimidex treatment...

Re: Thyroid desease and breast cancer
 

I was dx with subclinical hypothyroidism 12 months before by bc dx. I tried, unsucessfully, to take Synthroid (i.e., thyroid hormone) for 4 months before I developed the most horrible itching imaginable, which I have since learned was most likely my immune system reacting to the bc. I stopped the Synthroid and was dx with bc 8 months later. I am certain that this is what precipitated the bc.

Hopeful

Re: Thyroid desease and breast cancer
 

I am planning to start posting again soon (really), and I will definitely follow-up this thread because I am quite sure that thyroid has an enormous impact on breast cancer. In the meantime, here are a few of the (somewhat conflicting) links I've collected since I concluded that too much exogenous T3 (i.e., Armour and Cytomel) was the cause of my cancer:

Effects of thyroid hormones on human breast cancer cell proliferation

http://www.ncbi.nlm.nih.gov/pubmed/18328691

Prospectively measured triiodothyronine levels are positively associated with breast cancer risk in postmenopausal women

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2917028/

Hypothyroidism Enhances Tumor Invasiveness and Metastasis Development
http://www.plosone.org/article/info:...l.pone.0006428

Hypothyroxinemia as a goal in cancer management by triiodothyronine (T3) substitution for supplemental L-thyroxine (T4) and T3 modulated hypothyroxinemia

http://www.asco.org/ascov2/Meetings/...stractID=83728

I have more but the data is on my other computer (which isn't functional at the moment). I also have data that makes a connection between thyroid issues and prostate cancer.

As soon as I have a grip, I'll add to this.

rl

Re: Thyroid desease and breast cancer
 

Since thyroid disease is considered autoimmune, it's likely to be considered a weak link in the huge and unknown chain of events that cause our systems to allow cancer "in."

Re: Thyroid desease and breast cancer
 

I don't know which way my case would impact your search for antectodal information on the possible link between thyroid disease and breast cancer. But I was diagnosed as sub-clinical hyperthyroid for almost 8 years before learning that I also had breast cancer. My oncologist didn't think there was a connection. My endocrinologist thought there might be. At any rate, my thyroid was removed after I was finished with Herceptin, chemo and radiation because it was covered with lesions that looked suspicious to the doctors. The thyroid turned out to be benign and I am now on levothyroxine for life. I suspect there is a link.---bird

Re: Thyroid desease and breast cancer
 

Hmm. Interesting.

My two CT scans noted issues with my thyroid. I saw an endocrinologist, and had it biopsied on both sides. The nodule that looked most like it was cancerous tested benign. (It's big--2 cm--has its own blood supply and has calcification). The biopsy on the other side was inconclusive. Thyroid function is normal.

Re: Thyroid desease and breast cancer
 

My thyroid was removed 18 months before my BC Dx. I take Levotyrox ever since. I had 30 nodules and a biopsy in one of them showed pre cancerous cells so it was decided to take the thyroid out. I don't know if there is a link. Michka

Re: Thyroid desease and breast cancer
 

http://www.ncbi.nlm.nih.gov/pubmed/21934341
Onkologie. 2011;34(8-9):422-6. Epub 2011 Aug 22.
Association of the functional polymorphism C677T in the methylenetetrahydrofolate reductase gene with colorectal, thyroid, breast, ovarian, and cervical cancers.

http://www.ncbi.nlm.nih.gov/pubmed/21835042http

World J Surg Oncol. 2011 Aug 12;9:88.
Nulliparity enhances the risk of second primary malignancy of the breast in a cohort of women treated for thyroid cancer.

http://www.ncbi.nlm.nih.gov/pubmed/21914918

Epidemiol Prev. 2011 May-Aug;35(3-4):216-21.
[Population ageing effect on number of cancer cases: Italian cancer registries data].

Re: Thyroid desease and breast cancer
 

I find this thread interesting. I have been on Thyroid medicine since 2001 (Armor Thyroid). About three years ago doctors could no longer get Armor due to it being pulled from market and my doc switched me to Cytomel. At about the 3 yr mark on Cytomel, I was dx with IDC - left breast, 2.3cm tumor. I have no family history of BC and have wondered just how I got this. I have a HER2+ tumor, ER-, PR-. I was researching Cytomel and the production of high level of growth hormones (since I have a growth hormone fed tumor) when I came across this thread. I am highly suscpicious of thryoid or thyroid medication involvement in my BC.

Re: Thyroid desease and breast cancer
 

I was diagnosed as hypothyroid 6 months before my breast cancer dx. 5 years later I have been dx with papillary thyroid cancer. I had a total thyroidectomy and am now snythroid. Incidentally ultrasound showed nodules on both left and right side, but needle biopsy was negative and my ocologist wanted the thyroid removed, that is when it did prove to be cancer. Both endocrinologis and oncologist said the 2 cancers were related.