Prognostic variables and calcitonin in medullary thyroid cancer.
OBJECTIVE
Medullary thyroid cancer (MTC) is a nonepithelial, neuroendocrine tumor with a more aggressive clinical behavior than differentiated thyroid cancer. The purpose of the study was to review a single institution's experience with MCT since 1969.


METHODS
Retrospective cohort study.


METHODS
A retrospective review of 30 patients treated for MTC at a tertiary care referral center between 1969 and 2000. There were 17 female and 13 male patients, median age at presentation was 38 years, and median follow-up for survivors was 12.4 years.


RESULTS
Seventy percent of patients had sporadic MTC, 6.7% had familial MTC, 16.7% had multiple endocrine neoplasia syndrome type IIA, and 6.7% had multiple endocrine neoplasia syndrome type IIB. The cumulative overall survival rates at 5, 10, and 20 years were 97%, 88%, and 84%, respectively; disease-free survival rates were 97%, 74%, and 29%, respectively. Advanced tumor stage (P = .014) and multiple endocrine neoplasia syndrome type IIB predicted decreased disease-specific survival. Variables affecting disease-free survival were post-thyroidectomy calcitonin level (P = .001), vascular invasion (P = .005), perineural invasion (P = .010), extrathyroidal extension (P < .001), and the presence of nodal metastases (P = .001). Locoregional control rates were 83% at 5 years and 70% at 10 years. Vascular invasion (P = .004), extrathyroidal extension (P = .008), and post-thyroidectomy basal calcitonin level (P = .003) predicted locoregional failure. Many patients in the series experienced prolonged survival despite elevated calcitonin levels.


CONCLUSIONS
Long-term disease-free survival is uncommon in MTC, but the study data indicate that the majority of patients with MTC live for prolonged periods, despite biochemical evidence of persistent disease. Adverse pathological features such as extrathyroidal extension and vascular and perineural invasion were predictors of disease recurrence. The use of serum markers in the follow-up of patients with MTC must be interpreted within the clinical context.
Clark
Jonathan R
JR
Department of Otolaryngology-Head and Neck Surgery, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario, Canada.
Fridman
Tauba R
TR
Odell
Michael J
MJ
Brierley
James
J
Walfish
Paul G
PG
Freeman
Jeremy L
JL
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D002116:Calcitonin / Q000378:metabolism*; D002272:Carcinoembryonic Antigen / Q000032:analysis / Q000378:metabolism*; D018276:Carcinoma, Medullary / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D002648:Child; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000453:epidemiology; D009367:Neoplasm Staging; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012737:Sex Factors; D016019:Survival Analysis; D013964:Thyroid Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D013965:Thyroidectomy / Q000379:methods; D016896:Treatment Outcome
D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D002116:Calcitonin