Factors affecting long-term survival of Taiwanese patients with medullary thyroid carcinoma

Background and Purpose: Long-term survival of patients with postoperative recurrence of medullary thyroid carcinoma (MTC) is not uncommon. This study assessed whether local or distant recurrence after operation is a significant factor affecting long-term in Taiwanese patients with MTC. The benefit of family screening for MTC patients on survival was also evaluated. Methods: A total of 54 patients with a diagnosis of MTC by pathology or cytology during the period from 1997 to 2000 were included in the study. Survival curves were compared between different groups according to age, gender, tumor size, metastasis, recurrence after surgical intervention, or diagnosis before and after the performance of family screening for MTC patients. Results:The 5-year survival rate using the Kaplan-Meier method was 84.1% (95% confidence interval, 73.9% to 94.2%), and the 10-year survival was 77.6% confidence interval, 64.9% to 90.3%). Patients with lymph node metastasis and distant metastasis before operation had significantly shorter survival. Surprisingly, recurrence was not associated with shorter survival. Patients diagnosed after the start of family screening in 1991 had fewer lymph node metastases before operation, and lived longer. Conclusions: Patients with lymph node or distant metastasis before operation had poor prognosis. However, local or distant recurrence after operation did not influence survival. Efforts to obtain early diagnosis and surgical intervention before tumor metastasis, such as family screening, resulted in improved survival.