Evaluation of Survival and Postoperative Radiation Among Patients with Advanced Medullary Thyroid Carcinoma: An Analysis of the National Cancer Database.

BACKGROUND: This study compared survival between patients who had medullary thyroid cancer (MTC) treated with surgery alone and patients who underwent surgery and radiation (SRT). METHODS: Patients from the National Cancer Database (NCDB) with a diagnosis of stage 3 or 4 MTC, lymph node disease, and no distant metastases between 2008 and 2016 were studied. Kaplan-Meier analyses and log-rank statistics were used to estimate and compare overall survival between patients treated with surgery alone and those treated with SRT. Mutlivariable Cox proportional hazards models and propensity-matching were used to adjust for confounding and selection bias. RESULTS: Among 1370 patients, 1112 (81%) received surgery alone, and 258 (19%) received SRT. The hazard ratio for mortality in the SRT group was 1.784 (95% confidence interval [CI] 1.313-2.43) after multivariable adjustment for confounding variables. Furthermore, SRT remained associated with a higher mortality rate (p < 0.008) after propensity-matching in an effort to adjust for selection bias. CONCLUSIONS: This analysis of NCDB patients showed that SRT is associated with a significantly higher mortality rate among patients treated for stage 3 or 4 IV MTC with positive lymph node disease. Although this observation can be attributed to unmeasured confounders or selection bias, the cause for the profound survival differences deserves prospective evaluation, especially as adjuvant therapies for this disease continue to evolve.

Significant racial differences in the incidence and behavior of the follicular variant of papillary thyroid carcinoma.

BACKGROUND: Increased detection of papillary thyroid cancer (PTC) has led to overtreatment of the largely indolent follicular variant (fvPTC). To guide management of non-aggressive lesions, we investigated whether race predicts PTC variant and tumor behavior. METHODS: Analysis of 258 973 patients from the National Cancer Database diagnosed with PTC in 2004-2014. Clinical and tumor information was compared by race. Multivariate logistic regression was used to predict fvPTC, extrathyroidal extension (ETE), and lymph node metastasis (LNM) of fvPTC. RESULTS: Blacks had the highest fvPTC rate (40% vs white 30%, Hispanic 26%, Asian 25%, P < .001). Blacks had higher odds of fvPTC (aOR = 1.33, 95% CI: 1.28-1.37) and lower odds of ETE than whites (aOR = 0.90, 95% CI: 0.82-0.99) (P < .001). Hispanics and Asians had lower odds of fvPTC (aOR = 0.89, 95% CI: 0.86-0.92 and aOR = 0.81, 95% CI: 0.79-0.84) and higher odds of LNM and ETE than whites (P < .001). CONCLUSIONS: Racial disparities in fvPTC incidence and behavior should be considered to optimize diagnosis and treatment planning.