Brought to you by Mary Shomon, Your Thyroid Guide
Index of Q&As with Dr. David Derry
Topic: Breast Cancer, Tamoxifen, Thyroid & Weight Loss
A Reader Writes:
I went through chemo for breast cancer and radiation... I was told that the radiation may have caused my hypothyroid...but, who's to say. I put on alot of weight from my breast cancer and esp. being on Tamoxifen for 5 yrs. I got diagnosed with the thyroid thing about 1/2 yr ago & I was dying to lose weight finally being off the Tamoxifen... Now I feel stuck again because I can't lose the 65lbs.... and I believe its from the thyroid. I'm taking Levoxyl for six months maybe 7 and I had a blood test with my primary about 2 months ago. She said I was fine and I shouldn't be gaining weight...I'm not really gaining Ive been 189-192 off and on now for months and months... I can't seem to lose weight. What should I do?"
David Derry Responds:
First, radiation to your breast for prevention of local recurrences can affect your thyroid gland. The thyroid gland in your neck is in close proximity to your breast and depending on the angle used by the radiation machine, the dosage used and also how good the machine is at preventing radiation scatter, the radiation can cause affects both short term and long term on your thyroid gland health.(1)
In addition chemotherapy (Tamoxifen included) are toxic compounds and can have side effects on many organs including the thyroid gland. The combination of chemotherapy and radiation can lead to clinically obvious low thyroid disease. However this low thyroid condition can be masked by normal thyroid function tests. Blood thyroid function tests become unreliable when a patient is treated with such agents as radiation and chemotherapy. Because they are unreliable, common sense dictates treat patients on the basis of their symptoms. Your weight problem is just one of them. I would expect that a detailed medical functional inquiry of all organ systems would reveal many areas showing low thyroid function.
Having said all that, breast cancer has been one of my interests for many years. I would like to tell you my thoughts on breast cancer and thyroid disease in an abbreviated form. Breast cancer takes around 20-30 years to develop. The discovered lump represents the end stage of slow cancer progression over decades. The longest period is the first phase of cancer development. This phase which is often called pre-cancerous happens as as a normal cell is gradually turned into a cancer cell. These pre-cancerous lesions are known as fibrocystic disease (lumpy, tender breasts) of the breast. (2-3,13-14) Most fibrocystic disease is benign, harmless and has no consequences.
On the other hand, some more advanced forms of fibrocystic disease have clearly defined tendencies towards breast cancer. So there are grades of fibrocystic disease with some of the cells looking more abnormal than in the benign forms. The greater the difference in the cells from normal (abnormal) the greater chance of these cells converting to a cancer cell over 10-20 years. So if you have fibrocystic disease still at the age of 45-55, you likely have had this for many years. There maybe then a significant chance the cells may change into a cancer cell. The good news is that it can be cleared up completely with a daily intake of iodine.(9)
In 1993 Ghent and Eskin (2) published a landmark paper on the treatment of severe fibrocystic disease of the breast with iodine supplements. This paper was the result of more than 30 years of marvelous research by Dr. Bernard. A. Eskin of the Medical College of Pennsylvania in Philadelphia. First in animals and then in humans he proved fibrocystic disease of the breast is the result of low dietary iodine. He has shown also that this can go on to develop into breast cancer.(2-8) I feel Dr. Eskin's research represents a major step toward conquering breast cancer and likely other cancers.
Our main significant source of iodine in our diets is iodized salt. But since the high blood pressure studies in the 1950s on salts and their effects on blood pressure, there has been a steady urging, on all women and the elderly especially, to decrease their salt intake. Women are also told to restrict salt in pregnancy. This salt avoidance leads to a relative dietary iodine deficiency. What's more children are also being taught to restrict their salt intake because of obesity. If this lowers the children's iodine intake then they will end up low thyroid and gain even more weight. Although there is still iodine in the diets of women it is much lower in general than was anticipated if they were taking a normal salt diet. (10-13) By law in some countries, but not in the United States, iodine is put into table salt. All other sources of salt, such as processed fast foods do not have iodine in them. So children can be eating a lot of salt but without any iodine in it.
If it is true there has been a general decrease in salt intake and thus iodine intake since the 1950s, there should have been a general increase in the number of women with fibrocystic (lumpy) disease of the breast. But if as well even lower iodine intake was occurring in the female population, worse forms of fibrocystic disease would occur which are statistically directly related to breast cancer. The chances of getting breast cancer then go up considerably. Now if we put this together with the incidence of breast cancer going from 1 in 23 in the mid 1960s to 1 in 8 currently then it seems to fit together. Over the last 80 years hundreds of publications have confirmed statistical correlations between the worse forms of fibrocystic disease of the breast and subsequent breast cancer. Unfortunately if you have fibrocystic disease you really don't know what type you have without a biopsy. On the other hand if you take iodine in adequate amounts daily all of the fibrocystic disease disappears so that you are essentially preventing breast cancer from occurring. If a cancer has already started it is unlikely it will be stopped with the iodine at that dose.
From my personal investigations cancer is roughly divided into two phases. The first part is the pre-cancerous phase (before cancer) and involves the change of a normal cell into a cancer cell. This first phase of cancer development takes about 10-30 years. Iodine in adequate doses stops and reverses this stage of the cancer process by causing the natural death of abnormal cells (apoptosis). Iodine circulates throughout the body in the extracellular fluids found between the cells of the body. If cell surface proteins have the amino acid tyrosine on the outside, the passing iodine reacts with this tyrosine. This little reaction denatures the protein and thus kills the cell. It is implied all vertebrate cell membranes do not have tyrosine on the portion of the protein sticking out into the extracellular fluid.
However, the intra membrane proteins may have tyrosine which is only exposed when the membrane is distorted by abnormal cell development such as we see in the pre-cancerous forms of fibrocystic disease. This would then expose the tyrosine to the iodine passing in the extracellular fluid. Again the iodine would denature the protein by reacting with the tyrosine and thus kill off the cell. So thus we have surveillance system for removing abnormal cells from our bodies. On the other hand low iodine intake allows cells to proceed and develop towards cancer. This is more indirect because the gradual increase in abnormal cells are just not being eliminated from the body because there is inadequate iodine to carry this out.
Once the cell has become a cancer cell then it can take two different turns. It can multiply and spread or it can multiply and just stay where it is. The second is called carcinoma in situ. (cancer at the site) The second phase(cancer multiplying and spreading) is the part we are all familiar with. Since on average breast cancer cells double every 100 days, it takes 9 years before mammograms can pick it up and around 11 years before we find it ourselves. (15)
This second clinical part of the cancer phase (the spreading) seems to be arrested by adequate levels of thyroid hormone in all tissues. Thyroid hormone completely controls the connective tissue which forms a strong sieve-like barrier to the passage of cancer cells trying to spread.(16-18) Low levels of thyroid hormone in the tissues (especially connective tissues) promotes the spread of cancer cells. So the body cancer defense system has two parts iodine for the first pre-cancer phase and thyroid hormone and iodine together for the second clinical phase. There is some overlapping of these two defense systems. The excess iodine flows out in the urine. Of course, because the iodine flows out in the urine it is preventing the development of abnormal cells in the bladder and kidney system at the same time. This then prevents cancers developing there.
Now you ask how much is adequate thyroid hormone? Clinically, it means, for you personally, enough thyroid to bring your weight back down. With the increase in metabolism caused by the thyroid together with the thyroid induced personal well-being and motivation you should easily return to your normal weight. You should feel good in yourself and coping well with your life (well-being). If those are all in place then you are likely on a dose that will stop the cancer from spreading. In a normal person this would be between 200 and 400 micrograms of thyroxine. If you combine thyroid hormone treatment with adequate amounts of iodine to prevent any new cancers from developing, then you likely have a good prognosis. For the 8 years I tried this regime on 10 breast cancer patients -- there were no recurrences and everyone felt well. There are exceptions to the dosage -- related to childhood frightening events. I will discuss this in another answer.(9)
An adequate dose of iodine can be defined as more than 4 mg per day. Lugol's solution is an iodine-in-water solution used by the medical profession for 200 years. One drop (6.5 mg per drop) of Lugol's daily in water, orange juice or milk will gradually eliminate the first phase of the cancer development namely fibrocystic disease of the breast so no new cancers can start. It also will kill abnormal cells floating around in the body at remote sites from the original cancer. Of course this approach appears to work for prostate cancer as prostate cancer is similar to breast cancer in many respects. Indeed, it likely will help with most cancers. Also higher doses of iodine are required for inflammatory breast cancer. As well we know that large doses of intravenous iodine are harmless which makes one wonder what effect this would have on cancer growth.
I hope this helps you understand breast cancer better.
1. Links,J.M. Chapter 16. Radiation physics and Chapter 17, Williams,E.D. Biologic effects of radiation on the thyroid. in Werner and Ingbar's The Thyroid. Eds Braverman, L.C. and Utiger,R.D. J.B. Lippincott Company 1991. Philadelphia pages 405-436.
2. Ghent,W.R., Eskin,B.A., Low,D.A., Hill, L.P.. Iodine replacement in fibrocystic disease of the breast. Can J Surg 1993; 36:453-460.
3. Ghent,W.R., Eskin, B.A.. Iodine deficiency breast syndrome. In: Medeiros-Neto G, Gaitan E, editors. Frontiers in Thyroidology, Proceedings of the Ninth International Congress, 1985. New York: Plenum, 1986: 1021-1026.
4. Eskin,B.A., Grotkowski,C.E., Connolly,C.P., Ghent,W.R.. Different tissue responses for iodine and iodide in rat thyroid and mammary glands. Biol Trace Element Res 1995; 49:9-19.
5. Eskin,B.A.. Iodine metabolism and breast cancer. Trans NY Acad Sci 1970; 32:911-947.
6. Eskin,B.A.. Iodine and breast cancer. Biol Trace Element Res 1983; 5:399-412.
7. Eskin,B.A.. Dietary iodine and cancer risk. Lancet 1976; 8:807-808.
8. Eskin,B.A., Krouse,T.B., Modhera,P.R., Mitchell,M.A.. Etiology of mammary gland pathophysiology induced by iodine deficiency. In: Medeiros-Neto G, Gaitan E, editors. Frontiers in thyroidology, Proceedings of the Ninth International Congress. New York: Plenum, 1986: 1027-1031.
9. Derry, DM. Breast Cancer and iodine Preventing and surviving.Trafford Publishing company, Victoria, Canada. 2001.
10. Lee,K., Bradley,R., Dwyer,J., S. L. Lee,S.L.. Too much or too little: The implication of current Iodine intake in the United States. Nutrition Reviews 57:177-181, 1999.
11. Hollowell,J.G., Staehling,N.W., Hannon,W.H. et al. Iodine nutrition in the United States. Trends and public health implications: Iodine excretion data from national health and nutrition examination surveys I and III (1971-1974 and 1988-1994). J Clin Endocrinol Metab 83:3401-3408, 21998.
12. Thomson,C.D., Colls,A.J., Conaglen,J.V., Macormack,M., Stiles,M., Mann.J.. Iodine status of New Zealand residents as assessed by urinary iodide excretion and thyroid hormones. British Journal of Nutrition 78 (6):901-912, 1997.
13. Glinoer,D. Feto-maternal repercussions of iodine deficiency during pregnancy. An update. Annales d Endocrinologie. 64 (1):37-44, 2003.
14. Gullino PM. Natural history of breast cancer. Cancer 39, 2697-2703. 1977.
15. Clark WH. The nature of cancer: morphogenesis and progressive (self ) disorganization in neoplastic development and progression. Acta Oncol 1995; 34:3-21. 16. Clark WH. Tumour progression and the nature of cancer. J Cancer 1991; 64:631-644. 17. Smith,T.J., R. S. Bahn, and C. A. Gorman. Connective tissue, glycosaminoglycans, and diseases of the thyroid. Endocr.Rev. 10:366-391, 1989.
About Dr. Derry:
Dr. Derry is no longer practicing medicine.
These answers are personal opinions. Please discuss any ideas you get with your physician.
Born in 1937, I am at the cutting edge of the war baby boom. With one exception the baby boomers tend to do what I do in large numbers about ten years later. The exception was that after finishing my internship at the Toronto General Hospital in 1963, as I had planned, I started a PhD in biochemistry at the Montreal Neurological Institute at McGill University in Montreal. After completing my PhD, I was hired by the Department of Pharmacology at the University of Toronto to teach and do research. Within a short time I became a Medical Research Council Scholar, which meant the Medical Research Council of Canada paid my salary to do research. Domestic rearrangements suddenly placed five children between the ages of 5 and 9 under my care. I abandoned my research career and took all five children, a new wife and dog out west to Victoria British Columbia.
My aim in 30 years of General Practice (an honor and a privilege) was to learn carefully and persistently how to listen to the patient. This is the one area of medical research that has gone almost totally un-examined. Sir William Osler, who I feel was the greatest physician of all time, said: if you listen to the patient they will usually give you the diagnosis and if you listen even more carefully they will likely indicate the best treatment for them. Gradually with the help of multiple self-development courses over the years I learned to listen by just getting my ego out of the way. From my patients I learned everything. Because of the arrival of effective treatments with potential side-effects, in 1945 the out-dated Hippocratic oath of do no harm was replaced with a new principle of ethical patient care namely Consider first the well-being of the patient. Combining extensive medical-literature reading with what I learned daily from patients clarified which approaches and treatments assured the well-being of the patient.
Read more Q&As with Dr. David Derry now