Similar stage-dependent survival and outcome in sporadic and hereditary medullary thyroid carcinoma.

Raue, Friedhelm; Bruckner, Thomas; Frank-Raue, Karin

CONTEXT Long-term data are scarce on large cohorts with sporadic (sMTC) and hereditary medullary thyroid carcinoma (hMTC). OBJECTIVES To compare long-term disease-specific survival (DSS) and outcomes between sMTC and hMTC groups. DESIGN Retrospective analysis. SETTING German tertiary referral center. PATIENTS 673 patients with MTC that underwent surgery from January 1974 to July 2019. INTERVENTION None (observational study). MAIN OUTCOME MEASURE Differences between sMTC and hMTC in long-term, stage-dependent survival and outcomes. RESULTS Surgery was performed at median ages of 49 years for sMTC (n=477, 44% male) and 29 years for hMTC (n=196, 43% male; p<0.0001). The mean follow-up times were 9.2±8.0 (sMTC) and 14.6±10.3 years (hMTC). Age and tumor stage at diagnosis were significantly different between the two groups (p<0.0001). The sMTC and hMTC groups had different overall DSS (log rank, p=0.0183), but similar stage-dependent DSS (log rank, p=0.1242 to 0.8981). In a multivariate analysis, sMTC and hMTC did not differ in DSS (HR=1.56, 95%CI=0.94-2.57), but in both groups, a worse DSS was significantly associated with age at diagnosis (HR=1.04, 95%CI=1.02-1.05), male sex (HR=0.49, 95%CI=0.32-0.76), and stages III and IV at diagnosis (HR=20.00, 95%CI=2.74-145.91 and HR=97.47, 95%CI=13.07-726.67, respectively). The groups had significantly different (p<0.0001) outcomes (i.e., cured, minimal residual disease, structural detectable disease, and death), but similar stage-dependent outcomes (p=0.9449 to 0.0511), except for stage III (p=0.0489). CONCLUSION Patients with sMTC and hMTC had different ages of onset, but similar stagedependent DSS and outcomes after the MTC diagnosis. This finding suggested that tumor behavior was similar in sMTC and hMTC. PRÉCIS This observational study of 673 patients with sporadic (n=477) and hereditary MTC (n=196) revealed similar disease-specific survival rates and outcomes, which suggested similar tumor behavior.