Determinants of remission in a case series of medullary thyroid carcinoma

We aimed to present the clinical results of patients with medullary carcinoma under follow-up in our center and to determine parameters affecting remission and lymph node metastases.

A retrospective analysis was performed of the medical records of 27 patients with MTC who were followed up between 2004 and 2020.

The mean age at diagnosis was 47.7 ± 14 years. The mean follow-up was 7.29 ± 4.9 years. Metastatic neck lymphadenopathy was detected in eight (29.6%) patients; none had distant metastasis at the time of diagnosis. The median tumor diameter was 1.50 (range: 0.4–6) cm. The median postoperative calcitonin level was 3.3 (range, 0.5–871) ng/L. Relapse occurred in 2 (range, 1–14) years after the first surgery in three (11.1%) patients. In the last visit, 7 (25.9%) patients had a structural incomplete response, and three (11.1%) patients had a biochemical incomplete response. Seventeen (59.3%) patients were in remission, no patients died of MTC or any other cause. Elevated postoperative calcitonin level was a significant prognostic parameter for remission (p = 0.12) and lymph node metastasis (p < 0.001).

Elevated postoperative calcitonin level and perithyroid soft tissue invasion were significant prognostic parameters for remission and lymph node metastasis. Postoperative calcitonin level and calcitonin doubling time should be considered for prognostic and survival risk assessments.