Combined radiation and chemotherapy versus monotherapy for anaplastic thyroid cancer: A SEER retrospective analysis

The effect of combined radiation and chemotherapy (combination therapy) versus monotherapy on anaplastic thyroid carcinoma (ATC) has not yet been clear.

We identified 516 ATC patients during 2010-2015 from the Surveillance, Epidemiology and End Results (SEER) database and evaluated their survival outcome using the Kaplan-Meier method, Cox regression analysis and propensity score matching (PSM) technique.

The median overall survival (OS) among the entire cohort was 3 months (95 % confidence interval [CI], 2.58-3.42 months), and the 6- and 12-month OS rates were 29 % (95 % CI, 25.01%-32.88 %) and 13 % (95 % CI, 10.60%-16.58 %), respectively. Multivariable analysis demonstrated that ATC patients not receiving radiotherapy or chemotherapy were unquestionably associated with worse OS (hazard ratio [HR] 3.000, 95 % CI, 2.390-3.764) and cancer-specific survival (CSS) (HR = 3.107, 95 % CI, 2.388-4.043), compared with those receiving combination therapy. However, combination therapy did not predict better prognosis compared with monotherapy (all P > 0.05). After PSM, the median OS and CSS were also not significantly improved in patients undergoing chemoradiotherapy versus chemotherapy alone (OS, P = 0.382; CSS, P = 0.420) or radiotherapy alone (OS, P = 0.065; CSS, P = 0.251).

Combination therapy, compared to monotherapy, does not have the expected improvement in survival beyond the benefits achievable with each single-modality treatment, necessitating further prospective research to tailor its treatment management.