Survival advantage of chemoradiotherapy in anaplastic thyroid carcinoma: Propensity score matched analysis with multiple subgroups

BACKGROUND: We compared overall survival (OS) between radiation therapy (RT) and chemoradiotherapy (CRT) in patients with anaplastic thyroid carcinoma (ATC) using a large database. METHODS: The National Cancer Data Base was queried for ATC patients diagnosed between 2004 and 2013 who received RT or CRT. Groups were balanced by propensity score matching (PSM) on nine relevant variables. OS was also examined in five paired subgroups given known patient heterogeneity. RESULTS: Of 858 total patients, 575 received CRT and 283 received RT. CRT was associated with decreased risk of death (hazard ratio [HR] 0.66, P < .001), 1-year OS 25.5% vs 14.3%. A survival advantage to CRT was seen using PSM cohorts (HR 0.75, P = .006). Those receiving definitive surgery saw the greatest benefit to CRT over RT (HR 0.65, P = .009), 1-year OS 39.6% vs 20.4%. CONCLUSIONS: CRT is associated with decreased risk of death in ATC; the magnitude of CRT vs RT benefit varied by subgroup.