Hereditary medullary thyroid carcinoma in patients greater than 50 years old

Despite near complete penetrance and frequent early evaluation of medullary thyroid carcinoma (MTC) in multiple endocrine neoplasia 2 (MEN 2) variants, a significant minority of patients are evaluated later in life.

With the aim of characterizing the expression of hereditary MTC in an older cohort, MEN 2 patients from our institutional database who were evaluated after age 50 years were identified, and clinical data were reviewed.

Thirty-nine patients (36 MEN 2A, 3 FMTC, and no MEN 2B) who were evaluated after age 50 years were identified; they represented 9% of all MEN 2 patients who were enrolled in our program. Most of the patients (79%) had abnormal screening examinations, and the AJCC staging was significantly higher in this cohort compared with younger patients. Overall, 43% of the patients had normal calcitonin levels after operation. There were 3 observed MTC-related deaths, all from distant metastases; the overall survival rate was 86% at 5 years and 74% at 10 years. The distribution of RET mutations in this cohort was similar to younger patients.

These results suggest the presence of modifiers of MTC expression. Despite the tendency of older patients with hereditary MTC to have advanced stage disease at evaluation, they have high rates of biochemical cure, and the overall survival is excellent.