Progression of medullary thyroid carcinoma: assessment with calcitonin and carcinoembryonic antigen doubling times.
OBJECTIVE
The progression of medullary thyroid cancer is difficult to assess with imaging modalities; we studied the interest of calcitonin and carcinoembryonic antigen (CEA) doubling times and of Ki-67 labeling and mitotic index (MI).


METHODS
Fifty-five consecutive medullary thyroid carcinoma (MTC) patients with elevated calcitonin levels underwent repeated imaging studies in order to assess tumor burden and progression status. We looked for relationships between tumor burden and levels of calcitonin and CEA and between progression status according to the response evaluation criteria in solid tumors (RECIST) and calcitonin and CEA doubling times, and Ki-67 labeling and MI.


RESULTS
The calcitonin and CEA levels were correlated with tumor burden. Ten patients with calcitonin levels below 816 pg/ml had no imaged tumor foci. Among the 45 patients with imaged tumor foci, 19 had stable disease and 26 had progressive disease, according to the RECIST. The calcitonin and CEA doubling times were strongly related to disease progression, with very few overlaps: 94% of patients with doubling times shorter than 25 months had progressive disease and 86% of patients with doubling times longer than 24 months had stable disease. Ki-67 labeling and MI were not significantly associated with disease progression.


CONCLUSIONS
For MTC patients, the doubling times of both calcitonin and CEA are efficient tools for assessing tumor progression.
Laure Giraudet
Anne
A
Department of Nuclear Medicine and Endocrine Oncology, Institut Gustave Roussy and University Paris Sud, 94805 Villejuif Cédex, France.
Al Ghulzan
Abir
A
Aupérin
Anne
A
Leboulleux
Sophie
S
Chehboun
Ahmed
A
Troalen
Frédéric
F
Dromain
Clarisse
C
Lumbroso
Jean
J
Baudin
Eric
E
Schlumberger
Martin
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D002116:Calcitonin / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood*; D002277:Carcinoma / Q000097:blood*; D018450:Disease Progression; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000097:blood; D008297:Male; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000097:blood*; D013997:Time Factors
D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D019394:Ki-67 Antigen; D002116:Calcitonin