The role of heavy metals in thyroid cancer: A meta-analysis

Maaike van Gerwen; Eric Alerte; Mathilda Alsen; Christine Little; Catherine Sinclair; Eric Genden

doi:10.1016/j.jtemb.2021.126900

The role of heavy metals in thyroid cancer: A meta-analysis

J Trace Elem Med Biol. 2022 Jan:69:126900. doi: 10.1016/j.jtemb.2021.126900. Epub 2021 Nov 12.

Authors

Maaike van Gerwen¹, Eric Alerte², Mathilda Alsen³, Christine Little⁴, Catherine Sinclair⁵, Eric Genden⁶

Affiliations

¹ Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA; Institute for Translational Epidemiology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. Electronic address: maaike.vangerwen@mountsinai.org.
² Department of Medical Education, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. Electronic address: Eric.alerte@icahn.mssm.edu.
³ Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. Electronic address: Mathilda.alsen@mountsinai.org.
⁴ Department of Medical Education, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. Electronic address: Christine.little@icahn.mssm.edu.
⁵ Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. Electronic address: Cath.sinclair@ausdoctors.net.
⁶ Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. Electronic address: Eric.genden@mountsinai.org.

PMID: 34798515
DOI: 10.1016/j.jtemb.2021.126900

Abstract

Introduction: Metal ions are known to accumulate in the thyroid and some play an important role in the function and homeostatic mechanisms of the thyroid gland. Certain metal ions are known endocrine disruptors while others are classified to be carcinogenic. Although higher thyroid cancer incidence rates have been reported in regions with high metal levels in soil and drinking water, including volcanic regions, the effect of heavy metals on the thyroid is still poorly understood. To investigate the association between heavy metals and thyroid cancer, a comprehensive meta-analysis was performed to draw a more evidence-based conclusion for individual metal ions.

Material and methods: Nineteen studies were included in this meta-analysis, of which 9 studies reported blood metal ion levels, 8 studies reported tissue metal ion levels and 2 studies reported blood and tissue metal ion levels. The standardized mean difference (SMD) was calculated between thyroid cancer patients group and a control group (benign thyroid patients group or healthy controls group) per study.

Results: A significant positive SMD in manganese tissue levels between thyroid cancer patients and benign thyroid patients (SMD: 0.56 (95 % CI: 0.16, 0.95)) and a significant negative SMD in cobalt blood levels between thyroid cancer patients and healthy controls (SMD: -2.03 (95 % CI: -3.95, -0.10)) was found. No difference in levels of other metals in blood or thyroid tissue between thyroid cancer patients and non-thyroid cancer patients was noted.

Discussion and conclusion: The present meta-analysis therefore demonstrates the urgent need for future studies, especially given the increasing exposure of the general population to various environmental pollutants, including metal ions, and the thyroid cancer burden worldwide.

Keywords: Environment; Meta-analysis; Metals; Systematic review; Thyroid cancer.

Publication types

Meta-Analysis
Review

MeSH terms

Humans
Incidence
Metals, Heavy* / toxicity
Thyroid Neoplasms*

Substances

Metals, Heavy