Insular carcinomas of the thyroid exhibit poor prognosis and long-term survival in comparison to follicular and papillary T4 carcinomas.
BACKGROUND
Insular thyroid carcinoma was described as a tumor with aggressive behavior, and patients usually present themselves with an advanced tumor stage. Whether the insular component is an independent factor for poor prognosis remains unclear. Therefore, in the present study, we compared the survival of patients with advanced insular, follicular, and papillary thyroid cancer.


METHODS
The clinical behavior of tumors in three groups of patients with T4 thyroid carcinoma--8 patients with insular, 11 patients with follicular, and 21 patients with papillary thyroid carcinomas--was compared. Disease-free survival and disease-specific death were analyzed statistically. Cox regression analysis was used to evaluate the influence of histotype and other prognostic factors.


RESULTS
At 3 years, survival was 37.5% (mean 26 months) among patients with insular thyroid carcinoma, 80% (mean 59 months) among those with follicular, and 89% (mean 126 months) among those with papillary thyroid carcinomas (p = 0.007). Disease-free survival in patients without initial distant metastasis was worst in patients with insular thyroid carcinoma (20%) compared to those with follicular (75%) and those with papillary thyroid carcinomas (71%).


CONCLUSIONS
Patients with advanced insular thyroid carcinoma have a poorer outcome in comparison to patients with similar advanced stage who have follicular or papillary thyroid carcinoma.
Agha
Ayman
A
Department of Surgery, University of Regensburg Medical Center, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany. ayman.agha@klinik.uni-regensburg.de
Glockzin
Gabriel
G
Woenckhaus
Matthias
M
Dietmaier
Wolfgang
W
Iesalnieks
Igors
I
Schlitt
Hans J
HJ
D018263:Adenocarcinoma, Follicular / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D000231:Adenocarcinoma, Papillary / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000473:pathology; D013964:Thyroid Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D013965:Thyroidectomy