Clinical Outcomes of Differentiated Thyroid Cancer Patients with Local Recurrence or Distant Metastasis Detected in Old Age

Background: Differentiated thyroid carcinoma (DTC) shows a very good prognosis, but older patients have a higher recurrence rate and those show poor prognosis than younger patients. The aim of this study was to determine the clinical outcomes of thyroid cancer patients who experienced recurrence in old age according to the treatment strategy used. Methods: This retrospective observational cohort study was conducted at Asan Medical Center, Seoul, Korea. Among DTC patients with no evidence of disease after initial treatment, we enrolled 86 patients who experienced recurrence at an age >65 years from 1994 to 2012. Sixty-nine patients had local recurrence and 17 patients showed distant metastasis. Results: The mean age of patients at recurrence was 72 years. Patients were followed up for a median of 4.1 years after recurrence. Sixty-three of the 69 patients with local recurrence received adrlitional treatment, while the other six received conservative care. The cancer-specific mortality rate was 15.5% in the local recurrence group. Airway problems were the main cause of death in patients who did not receive further treatment for local recurrence. Among the 17 patients with distant metastasis, 10 underwent specific treatment for metastasis and seven received only supportive management. Seven of those 17 patients died, and the cancer-specific mortality rate was 35% in the distant metastasis group. Conclusion: The overall cancer-specific mortality rate was 20% in DTC patients in whom recurrence was first detected at an age >65 years. Mortality due to uncontrolled local disease occurred frequently in patients who did not receive definitive management for recurrence.