Nutritional Factors Associated With Thyroid Cancer and Nodules Using the Integrated Cancer Repository for Cancer Research (Icare2)
Purpose: The American Cancer Society’s most recent estimates for thyroid cancer in the United States for 2018 are approximately 53,990 new cases of thyroid cancer (40,900 in women, and 13,090 in men) and approximately 2,060 deaths from thyroid cancer (1,100 women and 960 men).
The lifetime risk of thyroid cancer in the US has tripled in the past three decades in large part due to the increased detection from increased use of thyroid ultrasound. Dietary habits can be important modifiable risk factors for different types of cancer, but the association between dietary factors and thyroid cancer has not been well studied. The goals of this capstone were to: 1) review the literature for the association between dietary factors and thyroid cancer, 2) describe demographic and behavioral characteristics of patients with thyroid nodules and cancer in a hospital-based registry, and 3) conduct a case-control study comparing dietary habits of patients with thyroid cancer or thyroid nodules to a control (cancer-free) population.
Methods: A case-control study was conducted using data from the iCARE2 database; a data and bioinformatics registry managed by the Fred & Pamela Buffett Cancer Center (FPBCC) that includes cancer patients, individuals at high risk for cancer (thyroid nodules in the case of thyroid cancer), and healthy non-cancer controls. We evaluated persons with thyroid cancer or thyroid nodules that enrolled between February 2008 and March 2018. A total of 368 thyroid cancer cases and 475 thyroid nodule cases were identified from the Thyroid Tumor and Cancer Collaborative Registry (TTC), and 223 controls were identified from the Great Plains Health Informatics Database (GPHID). Descriptive statistics (frequencies, percentages, medians, means, and standard deviation) were used to describe the demographics and socioeconomic factors for thyroid cancer cases, thyroid nodules cases, and controls. Two sample t-test was used to compare continuous variables and the Chi-square test was used to compare categorical variables. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for each dietary consumption factor using single variable logistic regression. Multivariable logistic regression model was used to assess confounding and create a final model. The covariates included in the final model were dietary consumption frequency (Yes or No), age at enrollment, gender, education, current BMI and drinking status. P-value
Implications: Deli meat, high sugar/low fiber cereals and mayonnaise were risk factors for thyroid cancer. Fried pork, grilled poultry, fish (grilled, BBQ, or fried) and fried eggs were protective factors for thyroid cancer. Smoking and alcohol assumption did not impact the association between dietary habits and thyroid cancer.