Preoperative calcitonin levels are predictive of tumor size and postoperative calcitonin normalization in medullary thyroid carcinoma. Groupe d'Etudes des Tumeurs a Calcitonine (GETC) - Cohen, R; Campos, J M; Salaun, C; Heshmati, H M; Kraimps, J L; Proye, C; Sarfati, E; Henry, J F; Niccoli-Sire, P; Modigliani, E (J Clin Endocrinol Metab, 2000)