Endocrine Abstracts

Background: Distant metastasis rarely occurs in differentiated thyroid carcinoma (DTC), but represents most common cause of death in patients with DTC. Lung and bone are the most frequent sites of distant metastases. This study investigated long term outcomes of lung metastasis in DTC patients and its prognostic factors influencing disease progression and cancer specific survival (CSS).

Methods: A total of 134 DTC patients presenting with lung metastasis from 1994 to 2012 were retrospectively analysed. Factors predictive of the outcome were determined by Cox-proportional model.

Results: With a median follow up of 81 months after surgery, the 5- and 1-year CSSs were 80 and 66%, respectively. The predictors of disease progression were older age (≥45 years), ¹³¹I non-avidity and co-existing bone metastases other than lung. Similarly, older age (≥45 years), ¹³¹I non-avidity, co-existing bone metastases and follicular pathology was associated with CSS. Cox proportional hazard ratio for progression-free survival and disease-free survival showed that older age was the only independent predictive factor for poor prognosis.

Conclusions: Older age, additional bone metastases, ¹³¹I non-avidity and follicular histology were found to be significantly associated with poor clinical outcome. Therefore, strict surveillance should be tried in these patients.