Multimodal treatment based on thyroidectomy improves survival in patients with metastatic anaplastic thyroid carcinoma: a SEER analysis from 1998 to 2015.

Background: The aim of this retrospective study was to evaluate multimodal treatments consisting of surgery, radiotherapy (RT) and chemotherapy (CT) in metastatic anaplastic thyroid carcinoma (ATC) patients using the Surveillance, Epidemiology, and End Results (SEER) database.

Methods: Patients with a histopathologic diagnosis of ATC between 1998 and 2015 were included. The endpoint of this study was overall survival (OS). The prognostic significance in terms of OS was analyzed by univariate and multivariate analyses.

Results: A total of 433 metastatic ATC patients were identified. The median OS was two months, with a 1-year OS rate of 6.9%. In the multivariate analysis, the factors significantly correlated with OS were age [<68 . ≥68 years old, P=0.032, hazard ratio (HR) =1.252], tumor size (<7 . ≥7 cm, P=0.004, HR =1.418; <7 cm . unknown, P=0.005, HR =1.424), surgery at the primary site (none/unknown . less than thyroidectomy, P<0.001, HR =0.623; none/unknown . thyroidectomy, P=0.001, HR =0.616), use of RT (P<0.001, HR =0.562) and use of CT (P<0.001, HR =0.621). In the subgroup analysis, the combination of thyroidectomy, RT and CT demonstrated the best OS outcome when compared with other therapeutic modalities.

Conclusions: Surgery, RT and CT were all strong prognostic factors for improved OS in metastatic ATC patients. In addition, treatment approaches consisting of thyroidectomy were beneficial compared with nonsurgical treatment. However, given the limited benefit of only a few months in the clinic, we suggest that thyroidectomy in combination with RT and CT should be delivered in selected patients with caution for better management of metastatic ATC.