Long-Term Outcome After Surgery for Medullary Thyroid Carcinoma: A Single-Center Experience.

Background: Medullary thyroid carcinoma (MTC) is a rare C cells-derived tumor, with a hardly predictable long-term prognosis. This study was aimed to evaluate the predictive factors of cure and survival after surgery for MTC in a monocentric series.

Methods: A retrospective analysis of the long-term outcomes was assessed in 255 MTC patients operated between 1980 and 2015 at Padua University hospital.

Results: Sporadic MTC occurred in 65.1% and hereditary MTC in 34.9% of patients. At a median follow-up of 93 months (range 7-430), the cure rate was 56.8%. The overall 10-year survival was 84.4%, and MTC-related death rate was 15.3%. Patients who died because of MTC had a median age of 61 years (range 21-84) and were at stages III-IV in all cases; deaths occurred in 18% of sporadic MTC, 6% of MEN2a and 66.7% of MEN2b patients. None of the patients at stages I-II died because of the disease, but 17.7% had persistent/recurrent disease. Based on univariate analysis, age, gender, genetic variant, extent and year of surgery, tumor size, lymph-nodal metastases and tumor stage significantly affected cure and survival rates. At multivariate analysis, only patient- and tumor-related features (age, lymph-nodal status and stage) remained significant independent prognostic factors.

Conclusions: Radical surgery is the only chance of definitive cure in MTC, but it is possible only at early stage; in advanced stages, even extensive surgery could not grant cure and prolonged survival. Stage, nodal metastases and age remain the main predictive factors for cure and survival.