Real-World Outcomes of Differentiated Thyroid Cancer in Oman: A Decade after ATA Guidelines

Abstract The aim of the study was to evaluate the application of the 2015 American Thyroid Association (ATA) guidelines for differentiated thyroid cancer (DTC) management in Oman and to identify predictors of excellent treatment response. This retrospective cohort study included DTC patients followed at Suhar Hospital, Oman, between January 2018 and June 2024. Data on demographics, histopathology, treatment modalities, and follow-up outcomes were extracted from electronic health records. Patients were stratified into low, intermediate, and high risk based on the ATA guidelines, and treatment responses were categorized as excellent, biochemical incomplete, structural incomplete, or indeterminate. Descriptive statistics summarized baseline characteristics and treatment patterns. Comparative analyses used t-tests for continuous variables and chi-squared tests for categorical variables. Logistic regression models identified predictors of excellent response, with odds ratios (ORs) and 95% confidence intervals (CIs) calculated. A total of 178 DTC patients were included, with a mean age at diagnosis of 38 years; 87.1% (n = 155) were females. The most common surgery was total thyroidectomy without neck dissection (56.7%, n = 101). The majority of patients (75.3%) were classified as low risk. Radioactive iodine (RAI) therapy was administered to 69.1% of patients, including 61% of low-risk cases. At a median follow-up duration of 48 months (interquartile range [IQR], 24–84; range, 6–204), 61.2% achieved an excellent response, with significant improvement in outcomes over time, including a decrease in positive thyroglobulin antibodies from 15.2 to 5.1% (p = 0.001) and an increase in no evidence of disease on neck ultrasound from 89.2 to 93.8% (p = 0.071). Multivariate analysis identified younger age (OR = 0.97; 95% CI: 0.94–0.99), receipt of RAI (OR = 3.54; 95% CI: 1.56–8.00), and low-risk ATA stratification (OR = 5.15; 95% CI: 1.61–16.53) as significant predictors of excellent response. This study highlights the frequent use of RAI in low-risk DTC patients in Oman, suggesting potential overtreatment. The identified predictors of excellent response can inform risk-adapted management strategies. Further research is needed to optimize DTC treatment in this population and align practices with international guidelines.