Who May Benefit From Radioactive Iodine Ablation of Intermediate-Risk Papillary Thyroid Cancer?
Posted: Thursday, August 6, 2020
A subset of patients with intermediate-risk papillary thyroid cancer who are male, older than age 45, and have a tumor larger than 20 mm may benefit from radioactive iodine ablation of the thyroid. A group led by Tao Wei, MD, of Sichuan University in Chengdu, China, published their findings in PLOS One.
“Radioactive iodine ablation decision-making should be considered on an individual basis rather than ‘one size fits all’ in intermediate-risk papillary thyroid cancer patients,” concluded the authors.
The group utilized the Surveillance, Epidemiology, and End Results database to retrospectively analyze outcomes for 23,107 patients with intermediate-risk papillary thyroid cancer who had undergone primary thyroidectomy with or without radioactive iodine ablation. Researchers analyzed the disease-specific survival rate and overall survival in patients with and without iodine ablation. They then used a subgroup analysis to understand which patients seemed to benefit most from treatment. Among this cohort, 70.2% had undergone radioactive iodine ablation, whereas 29.8% did not. Patients who were young, had multifocal lesions, extrathyroidal extension, and regional lymph node metastasis were more likely to receive the therapy.
Radioactive iodine ablation was found to significantly improve disease-specific survival compared with no ablation among the entire cohort when adjusting for clinicopathologic characteristics (hazard ratio = 0.65). On subgroup analysis, ablation was associated with improved disease-specific survival when compared with no ablation in male patients alone (hazard ratio = 0.47), those older than age 45 (hazard ratio = 0.34), and those with tumors larger than 20 mm (hazard ratio = 0.58). This association was not seen in other subgroups, including patients with multifocality or lymph node metastasis. Overall survival was significantly improved by radioactive iodine ablation among most clinicopathologic features, excluding only patients younger than 45, those who had no lymph node metastasis, or who underwent near total thyroidectomy/subtotal thyroidectomy.
Disclosure: The authors reported no conflicts of interest.