Clinical considerations for the treatment of secondary differentiated thyroid carcinoma in childhood cancer survivors

The incidence of differentiated thyroid carcinoma (DTC) has incr eased rapidly over the past several years. Thus far, the only conclusively established risk factor for developi ng DTC is exposure to ionizing radiation, especially when the exposure occurs in childhood. Since the number of chil dhood cancer survivors (CCS) is increasing due to improvements in treatment and supportive care, the number of patients who will develop DTC after surviving childhood cancer (secondary thyroid cancer) is also expected to rise. Currently, there are no recommendations for management of thyroid cancer specifically for patients who devel op DTC as a consequence of cancer therapy during childhood. Since complications or late effects from prior cancer treatment may elevate the risk of toxicity from DTC therapy, the medical history of CCS should be considered carefu lly in choosing DTC treatment. In this paper, we emphasize how the occurrence and treatment of the initial child hood malignancy affects the medical and psychosocial factors that will play a role in the diagnosis and treatment of a secondary DTC. We present considerations for clinicians to use in the management of patients with secondary DTC, based on the available evidence combined with experiencebased opinions of the authors.