Medullary thyroid cancer: A retrospective analysis of a cohort treated at a single tertiary care center between 1970 and 2005

Objective: To identify prognostic factors of clinical outcome and long-term survival in medullary thyroid cancer (MTC). Design: Retrospective case series of 51 consecutive patients ( mean age 46.9 years, 57% female) treated at a single tertiary university medical center from 1970 to 2005. Medical records were reviewed for demographic data, laboratory and clinical course, treatment, and long-term outcome. Main outcome: At presentation, 25 patients (49%) had local disease and 26 (51%) had metastatic disease ( three with distant metastases). RET mutations were identified in nine of 23 patients tested. The patients with hereditary disease were younger than the patients with sporadic disease ( p < 0.001) and had lower calcitonin levels at diagnosis ( p = 0.004) and more multicentric tumors ( p = 0.02). Initial surgery consisted of total thyroidectomy in 47 patients, with neck dissection in 26; 22 patients achieved long-term remission. The 5-, 10- and 15-year survival rates were 88%, 85%, and 77%, respectively. On univariate analysis, distant metastases during the course of the disease and elevated calcitonin levels postoperatively were significant prognostic factors of reduced survival ( p = 0.001 and 0.016, respectively). Lymph node involvement at initial surgery was associated with a lower remission rate ( p = 0.016) but had no impact on long-term survival ( p = 0.269). Conclusion: Patients with MTC have a generally favorable outcome, perhaps owing to recent advances in diagnosis and treatment. Although postoperative serum calcitonin level and distant metastases are the only determinants of long-term survival, the presence of cervical metastases is predictive of a higher risk of recurrent or persistent disease.