Fatal differentiated thyroid cancer.

Thirty-five patients who died of differentiated thyroid cancer were analyzed for factors affecting survival. The neck was the most common initial site of recurrence (62.0%). The lung was the most common metastatic site (56.7%). Major sites associated with death were locoregional recurrence (neck and mediastinum: 48.6%) and bone metastases (22.9%). By univariate analysis, local tumor extension, type of initial surgery, and residual tumor and/or existence of distant metastases at the initial operation were significant factors affecting survival. Stepwise multivariate analysis revealed that invasion of the esophagus and/or carotid artery shortened survival and that multiple surgeries extended survival. Our results suggest that to improve survival in patients with differentiated thyroid cancer, better locoregional control, including multiple surgical resection, is necessary.