Association between age and disease specific mortality in medullary thyroid cancer

Background: The aim of this study was to evaluate the association between age and disease specific mortality (DSM) among adults diagnosed with medullary thyroid cancer (MTC). Method: Surveillance, Epidemiology, and End Results (SEER-18) was used to analyze adult MTC patients stratified by age (18–64, 65–79, ≥80 years). Associations between patient demographics, tumor size, nodal status, metastatic disease, and extent of surgery on DSM was assessed with multivariable Cox regression. Results: Among 1457 patients with MTC, 1008 (69.2%) were younger adults, 371 (25.5%) older adults, and 78 (5.4%) were super-elderly. A significantly higher proportion of older adults and super-elderly had less than the recommended operation for MTC. On multivariable analysis, older adults and super-elderly were 2.9 and 6.7 times more likely to have an increased DSM (HR:2.91, 95% CI: 1.83–4.63; p < 0.001 and HR: 6.70, 95%CI: 3.69–12.20; p < 0.001). Extent of surgery or lymphadenectomy did not affect DSM. Conclusions: Increased age is an independent predictor of DSM in patients with MTC.