Banerjee M, et al. - In this population-based study, researchers intended to ascertain treated recurrent or persistent thyroid cancer, identify correlates of poor treatment-free survival, and define prognostic groups for treatment-free survival. In 9,273 subjects from the Surveillance, Epidemiology, and End Results Program–Medicare, they assessed treatment-free survival with a diagnosis of differentiated thyroid cancer between 1998 and 2012. Data reported that stage, tumor size, and receipt of radioactive iodine were the most crucial factors for predicting treatment-free survival. For treatment-free survival, five prognostic groups were identified with a prediction accuracy of 88.7%. They suggested that understanding treatment-free survival has implications for the care and long-term surveillance of patients with differentiated thyroid cancer.