Relevance of iodine intake as a reputed predisposing factor for thyroid cancer

Iodine is a trace element that is essential for the synthesis of thyroid hormone. Both chronic iodine deficiency and iodine excess have been associated with hypertrophy and hyperplasia of follicular cells, attributed to excessive secretion of TSH. This may be associated to thyroid cancer risk, parti...

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Main Authors: Knobel,Meyer, Medeiros-Neto,Geraldo
Format: Article in Journal/Newspaper
Language:English
Published: Sociedade Brasileira de Endocrinologia e Metabologia 2007
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27302007000500007
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spelling ftjscielo:oai:scielo:S0004-27302007000500007 2023-05-15T16:51:28+02:00 Relevance of iodine intake as a reputed predisposing factor for thyroid cancer Knobel,Meyer Medeiros-Neto,Geraldo 2007-07-01 text/html http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27302007000500007 en eng Sociedade Brasileira de Endocrinologia e Metabologia Arquivos Brasileiros de Endocrinologia & Metabologia v.51 n.5 2007 Iodine Thyroid cancer Iodine deficiency Iodine excess Carcinogenic agents Environmental effect journal article 2007 ftjscielo 2015-10-26T15:39:33Z Iodine is a trace element that is essential for the synthesis of thyroid hormone. Both chronic iodine deficiency and iodine excess have been associated with hypertrophy and hyperplasia of follicular cells, attributed to excessive secretion of TSH. This may be associated to thyroid cancer risk, particularly in women. Experimental studies have documented thyroid cancer induction by elevation of endogenous TSH, although in a small number of animals. Iodine deficiency associated with carcinogenic agents and chemical mutagens will result in a higher incidence of thyroid malignancy. Inadequate low iodine intake will result in increased TSH stimulation, increased thyroid cell responsiveness to TSH, increased thyroid cell EGF-induced proliferation, decreased TGFbeta 1 production and increased angiogenesis, all phenomena related to promotion of tumor growth. Epidemiological studies associating iodine intake and thyroid cancer led to controversial and conflicting results. There is no doubt that introduction of universal iodine prophylaxis in population previously in chronic iodine-deficiency leads to a changing pattern of more prevalent papillary thyroid cancer and declining of follicular thyroid cancer. Also anaplastic thyroid cancer is practically not seen after years of iodine supplementation. Iodine excess has also been indicated as a possible nutritional factor in the prevalence of differentiated thyroid cancer in Iceland, Hawaii and, more recently, in China. In conclusion: available evidence from animal experiments, epidemiological studies and iodine prophylaxis has demonstrated a shift towards a rise in papillary carcinoma, but no clear relationship between overall thyroid cancer incidence and iodine intake. Article in Journal/Newspaper Iceland SciELO Brazil (Scientific Electronic Library Online)
institution Open Polar
collection SciELO Brazil (Scientific Electronic Library Online)
op_collection_id ftjscielo
language English
topic Iodine
Thyroid cancer
Iodine deficiency
Iodine excess
Carcinogenic agents
Environmental effect
spellingShingle Iodine
Thyroid cancer
Iodine deficiency
Iodine excess
Carcinogenic agents
Environmental effect
Knobel,Meyer
Medeiros-Neto,Geraldo
Relevance of iodine intake as a reputed predisposing factor for thyroid cancer
topic_facet Iodine
Thyroid cancer
Iodine deficiency
Iodine excess
Carcinogenic agents
Environmental effect
description Iodine is a trace element that is essential for the synthesis of thyroid hormone. Both chronic iodine deficiency and iodine excess have been associated with hypertrophy and hyperplasia of follicular cells, attributed to excessive secretion of TSH. This may be associated to thyroid cancer risk, particularly in women. Experimental studies have documented thyroid cancer induction by elevation of endogenous TSH, although in a small number of animals. Iodine deficiency associated with carcinogenic agents and chemical mutagens will result in a higher incidence of thyroid malignancy. Inadequate low iodine intake will result in increased TSH stimulation, increased thyroid cell responsiveness to TSH, increased thyroid cell EGF-induced proliferation, decreased TGFbeta 1 production and increased angiogenesis, all phenomena related to promotion of tumor growth. Epidemiological studies associating iodine intake and thyroid cancer led to controversial and conflicting results. There is no doubt that introduction of universal iodine prophylaxis in population previously in chronic iodine-deficiency leads to a changing pattern of more prevalent papillary thyroid cancer and declining of follicular thyroid cancer. Also anaplastic thyroid cancer is practically not seen after years of iodine supplementation. Iodine excess has also been indicated as a possible nutritional factor in the prevalence of differentiated thyroid cancer in Iceland, Hawaii and, more recently, in China. In conclusion: available evidence from animal experiments, epidemiological studies and iodine prophylaxis has demonstrated a shift towards a rise in papillary carcinoma, but no clear relationship between overall thyroid cancer incidence and iodine intake.
format Article in Journal/Newspaper
author Knobel,Meyer
Medeiros-Neto,Geraldo
author_facet Knobel,Meyer
Medeiros-Neto,Geraldo
author_sort Knobel,Meyer
title Relevance of iodine intake as a reputed predisposing factor for thyroid cancer
title_short Relevance of iodine intake as a reputed predisposing factor for thyroid cancer
title_full Relevance of iodine intake as a reputed predisposing factor for thyroid cancer
title_fullStr Relevance of iodine intake as a reputed predisposing factor for thyroid cancer
title_full_unstemmed Relevance of iodine intake as a reputed predisposing factor for thyroid cancer
title_sort relevance of iodine intake as a reputed predisposing factor for thyroid cancer
publisher Sociedade Brasileira de Endocrinologia e Metabologia
publishDate 2007
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27302007000500007
genre Iceland
genre_facet Iceland
op_source Arquivos Brasileiros de Endocrinologia & Metabologia v.51 n.5 2007
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