Survival and Analysis for Mixed Medullary-Follicular Thyroid Carcinoma: based on SEER database
Abstract PurposeDue to lack of proper diagnostic tools, we aimed to establish a nomogram for Mixed Medullary-Follicular Thyroid (MMFTC) and comparison with AJCC staging in prognosis. MethodsData regarding 203 patients with MMFTC (ICD-O-3 codes 8346, 8347) between 2000 and 2016 from The Surveillance, Epidemiology, and End Results (SEER) database. X-tile program was used to evaluate the optimal cut-off values for continuous variables. Univariate and multivariate regression analyses were performed with the Cox proportional hazards regression model to analyze the independent factors related to prognosis. Construct cancer-specific survival (CSS) and overall survival (OS) were analyzed. The resulting values were compared with the nomogram and the American Joint Committee on Cancer (AJCC) staging using C-index, verification curve, internal validation and decision curve analysis (DCA).ResultsThe CSS nomogram presented the prognostic factors including year of diagnosis (p = 0.045), tumor size (p = 0.003), extrathyroidal extension (p = 0.009) and pN stage (p = 0.008), while the OS nomogram showed the prognosis factors including year of diagnosis (p = 0.011), age at diagnosis (p = 0.010), tumor size (p = 0.013), extrathyroidal extension (p = 0.008), pT2 stage (p = 0.021) and Radioactive implants or Radioisotopes (p = 0.031).The C-index, verification curve, internal validation and DCA for these nomograms showed better performance in comparisons with the AJCC staging.ConclusionThe more appropriate and efficient therapeutic strategies were showed by the two nomograms for clinical prediction of OS and CSS in MMFTC.