A. S. Moten1, H. Zhao2, A. I. Willis3 1Temple University Hospital,Department Of Surgery,Philadelphia, PA, USA 2Lewis Katz School Of Medicine At Temple University,Department Of Clinical Sciences, Section Of Biostatistics,Philadelphia, PA, USA 3Thomas Jefferson University,Department Of Surgery,Philadelphia, PA, USA
Introduction: The 2015 American Thyroid Association (ATA) Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer suggests that radioactive iodine (RAI) ablation is not routinely needed for treatment of patients with low-risk thyroid cancer. We sought to determine if disparities in the use of RAI ablation in low-risk thyroid cancer patients existed prior to publication of the ATA guidelines in order to identify patient groups who may be at risk of overtreatment with RAI after surgical treatment of low-risk thyroid cancer.
Methods: The Surveillance, Epidemiology and End Results (SEER) database was used to identify patients with papillary thyroid cancer diagnosed between 2011 and 2013. Low-risk thyroid cancer was defined as T1, N0 or M0 disease. Characteristics of patients with low-risk disease were compared to those who did not have low-risk disease. Odds of presenting with low-risk disease were determined. Among patients with low-risk disease, predictors of receiving RAI were determined. Chi-square analyses were used to compare categorical variables, two-sample t tests to compare mean age at diagnosis, and logistic regression to determine odds ratios. A p-value of ≤ 0.05 was used for all analyses to determine statistical significance.
Results: The study sample included 32,229 individuals, of which 17,286 (53.6%) had low-risk disease. Mean (SD) age at diagnosis was 50.0 (14.8) years; 24,815 (77.0%) were female; and 21,318 (66.2%) were white. Low-risk patients, compared to others, were older (mean age 51.3 versus 48.5 years; p-value < 0.001), more often female (81.6% versus 71.7%; p-value < 0.001), more often white (69.7% versus 62.0%; p-value < 0.001), and more often insured (87.6% versus 85.6%; p-value < 0.001). Nearly 25% of low-risk patients were treated with RAI. Predictors of overtreatment with RAI among low-risk patients included age less than 45 years (OR: 1.393; 95% CI: 1.250 – 1.552), age 45-64 years (OR: 1.275; 95% CI: 1.152 – 1.412), male sex (OR: 1.191; 95% CI: 1.086 – 1.305), Hispanic (OR: 1.236; 95% CI: 1.110 – 1.376) and Asian (OR: 1.306; 95% CI: 1.159 – 1.473) ethnicities, and more extensive lymph node removal surgery (OR: 1.243; 95% CI: 1.119 – 1.381). Among low-risk patients, no patient who received RAI died of their disease, and only 5 (0.04%) patients who did not receive RAI died of their disease. There was no survival benefit for patients who received RAI for low-risk disease compared to patients who did not receive RAI.
Conclusion: Patients with low-risk thyroid cancer were more likely to receive RAI after surgery when not indicated under ATA guidelines if they were younger, male, Hispanic or Asian, or underwent extensive lymph node surgery. Identification of groups at risk for overtreatment can help impact practice patterns and improve the effective utilization of healthcare resources.