A study of recurrence and death from papillary thyroid cancer with 27 years of median follow-up

BackgroundAlthough recurrence and death can occur in patients with papillary thyroid cancer (PTC) several years after being diagnosed, the necessary duration of follow-up for these patients remains unclear.MethodsThis was a single-institution, retrospective review of 269 patients with PTC. Cox proportional hazards model and Kaplan-Meier curves were used to identify risk factors for recurrence and death. Risk predictors included age, sex, radiation exposure history, extent of operation, radioactive iodine treatment, follicular variant of PTC (FVPTC), extrathyroidal invasion, multifocality, TNM status, and stage.ResultsMedian follow-up was 27 years. Of 269 patients, 180 (66%) were female, and 196 (73%) were ≤45 years of age. Recurrence and cancer-specific death rates were 28% and 9%, respectively. Time to recurrence (±SD) was 8.1 (± 8.3) years and to cancer-specific death was 9.0 (± 11.0) years; however, 11% of recurrences and 17% of deaths occurred after 20 years. Risk factors for recurrence were older age, FVPTC, T4 tumors, cervical lymph node involvement, metastases, and stage ≥ 4a. Predictors of death from PTC were older age, metastases, and stage ≥ 3.ConclusionBoth recurrences and death from PTC can occur more than 30 years after being treated, thus lifelong follow-up of patients with PTC is necessary.