Postoperative calcitonin levels may be a strong prognostic biomarker for long-term disease-free survival in medullary thyroid carcinoma (MTC), according to a new study published in the journal Thyroid. This is important because it may help define follow-up strategies for patients with the disease.

Levels of calcitonin are widely used for the diagnosis and prognosis of MTC. However, the role of undetectable postoperative calcitonin levels in long-term disease outcomes is not clear. 

In order to explore the relevance of postoperative calcitonin levels as a prognostic marker for long-term disease status in MTC, a team of researchers led by Ana Luiza Maia, MD, PhD, conducted a retrospective cohort study for which they collected data from 334 patients with the disease who were surgically treated. 


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The researchers divided the patients into 2 groups: those who had undetectable levels of calcitonin following the operation and those who had detectable levels. 

They found that 3 to 6 months after the operation, 141 patients (42.2% of all patients) had undetectable levels of postoperative calcitonin. After a median follow-up of 7.7 years, the majority (90.1%) of these patients (127 of 141) were disease-free, while 9.9% (14 out of 141) had persistent biochemical disease with stable calcitonin levels. No patient who had undetectable levels of postoperative calcitonin died of the disease.

Among patients who had detectable postoperative calcitonin, 136 (70.5%) had lymph node metastasis, and 63 (32.6%) had distant metastasis. Only 18 patients (9.2% of all patients with detectable postoperative calcitonin levels) achieved disease-free status. Less than a third of them (26.6%) had biochemical disease and 31.6% had persistent structural disease. A total of 63 of these patients (32.6%) died of disease-related events. 

The researchers identified undetectable postoperative calcitonin levels as an independent prognostic variable for disease-free status in MTC.

Reference

Duval MADS, Ferreira CV, Marmitt L, et al. An undetectable postoperative calcitonin level is associated with long-term disease-free survival in medullary thyroid carcinoma: results of a retrospective cohort study. Thyroid. Published online October 12, 2022. doi:10.1089/thy.2022.0295