Machens A, et al. - Researchers studied a cohort of patients with previously untreated medullary thyroid cancer (MTC) to determine the time to calcitonin normalization after initial surgery taking into account preoperative calcitonin level, nodal status and number of nodal metastases in Kaplan–Meier analyses. They included some 213 patients with node-negative and 182 with node-positive MTC in the study. Outcomes suggest typical normalization of calcitonin levels within 1 week; and within a fortnight in those with node-positive MTC and preoperative calcitonin levels of 500·1–1000 pg/ml. Calcitonin normalization takes longer time in correlation with node-positive MTC and preoperative calcitonin levels exceeding 1000 pg/ml, and with more than ten nodal metastases.