Adjuvant radioactive iodine therapy is associated with improved survival for patients with intermediate-risk papillary thyroid cancer

Abstract

Context: Papillary thyroid cancer (PTC) is the most common endocrine malignancy. The long-term prognosis is generally excellent. Due to a paucity of data, debate exists regarding the benefit of adjuvant radioactive iodine therapy (RAI) for intermediate-risk patients. Objective: The objective of the study was to examine the impact of RAI on overall survival in intermediate-risk PTC patients. Design/Setting: Adult patients with intermediate-risk PTC who underwent total thyroidectomy with/without RAI in the National Cancer Database, 1998-2006, participated in the study. Patients: Intermediate-risk patients, as defined by American Thyroid Association risk and American Joint Commission on Cancer disease stage T3, N0, M0or Mx, and T1-3, N1, M0, orMxwere included in the study. Patients with aggressive variants and multiple primaries were excluded. Main Outcome Measures: Overall survival (OS) for patients treated with and without RAI using univariate and multivariate regression analyses was measured. Results: A total of 21 870 patients were included; 15 418 (70.5%) received RAI and 6452 (29.5%) did not. Mean follow-up was 6 years, with the longest follow-up of 14 years. In an unadjusted analysis, RAI was associated with improved OS in all patients (P