Date of Award

January 2021

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Caroline Johnson


Background: In recent years, the incidence rate of thyroid cancer is increasing rapidly, including a significant increase in young aged group people. Environmental chemical exposure is a significant driver. With untargeted metabolomics approach, this study will perform an untargeted metabolomics approach to identify serum metabolites biomarkers associated with thyroid cancer and tumor size.

Methods: Serum samples of 100 thyroid cancer patients (50 cases and 50 controls) diagnosed between 2010 and 2011, were extracted for metabolites and analyzed by reversed-phase liquid chromatography-mass spectrometry (LC-MS) based untargeted metabolomics. All the analysis were conducted in both positive and negative Electrospray ionization (ESI) modes. Multivariate and univariate data analysis tools are applied to identify metabolic differences among different sample groups and metabolites associated with the thyroid cancer cases.

Results: No significant metabolic difference through multivariate analysis were observed among different sample groups (small case, large cases and controls). One metabolite methylcytosine [M-H2O-H] was identified through univariate analysis in the ESI negative mode when comparing cases (small cases and large cases) and controls, which can be caused by environmental exposure.

Conclusions: There were no significant metabolic differences among different sample groups. One metabolite methylcytosine [M-H2O-H] of thyroid cancer was identified. Future research with a larger sample size and measurement of environmental chemicals in cancer patients are needed to uncover the association between environmental chemical exposure and thyroid cancer.

Keywords: Environmental Health Sciences, Thyroid cancer, Environmental Chemicals, Endocrine disrupting, Untargeted metabolomics, Biomarkers;


This is an Open Access Thesis.

Open Access

This Article is Open Access