Date of Award

January 2015

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Yawei Zhang



Objective: Thyroid cancer incidence has increased substantially in the United States. Previous studies of the relationship between cigarette smoking and thyroid cancer have yielded conflicting results.

Methods: In order further clarify the association between cigarette smoking and risk of thyroid cancer, we analyzed data from a population-based case-control study in Connecticut in 2010-2011 including 462 histologically confirmed incident thyroid cancer cases and 498 population-based controls. Multivariate unconditional logistic regression models were used to estimate the associations between cigarette smoking and risk of thyroid cancer adjusting for potential confounders.

Results: Our data showed a decreased risk of well-differentiated thyroid carcinoma among microcarcinomas (tumor size less than or equal to 1cm) by current smoker (OR=0.30, 95%CI 0.13, 0.70), lowest intensity category (OR=0.33, 95%CI 0.15- 0.74) as well as longest duration category (OR=0.18, 95%CI 0.07-0.47). No significant associations were found between these smoking predictors and macrocarcinomas (tumor size larger than 1cm).

Conclusions: Our study findings are consistent with a number of several previous epidemiologic studies indicating that cigarette smoking is associated with a decreased risk of thyroid cancer. The research highlights the significance of distinguishing between microcarcinomas and macrocarcinomas in future research on etiology of thyroid cancer.


This is an Open Access Thesis.