Immunohistochemical expression of cyclooxygenase 2 in follicular carcinomas of the thyroid.
BACKGROUND
Cyclooxygenase 2 (COX-2) has been shown to be up-regulated and/or overexpressed in a variety of human neoplasms. However, limited data exist on the role of COX-2 in follicular carcinomas of the thyroid. Studies in this area are potentially significant, since therapeutic agents that inhibit COX-2 are currently available and could play a role in treatment.


METHODS
A retrospective clinicopathologic review with COX-2 immunohistochemical staining of 34 follicular carcinomas and 7 follicular adenomas with incomplete capsular penetration was performed.


RESULTS
The study included 41 patients (25 women; mean age, 50.9 years). All patients underwent gross total resection of the neoplasm. Fifteen carcinoma patients received adjuvant radiotherapy. Seven patients with follicular carcinomas developed recurrent disease: 3 patients were alive (mean follow-up, 10.1 years) and 4 patients died of metastatic disease (mean follow-up, 3.5 years). All remaining patients were disease free (mean follow-up, 5.9 years). Only 1 follicular adenoma with incomplete capsular penetration recurred (patient alive at 9 years). The remaining patients were disease free (mean follow-up, 4.9 years). The COX-2 staining was positive in 11 tumors (9 of 34 follicular carcinomas, 2 of 7 follicular adenomas with incomplete capsular penetration). A greater percentage of recurrences (36% COX-2 positive vs 13% COX-2 negative) and fatal tumors (18% COX-2 positive vs 7% COX-2 negative) occurred in patients who had COX-2-positive staining neoplasms.


CONCLUSIONS
Only a few follicular carcinomas (26%) and follicular adenomas with incomplete capsular penetration (29%) express COX-2 by immunohistochemical analysis. The data suggest that such expression of COX-2 may correlate with increased tumor recurrence and death; however, studies with larger numbers of patients will be needed to establish this.
Haynik
Denise M
DM
Department of Anatomic Pathology, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Prayson
Richard A
RA
D018263:Adenocarcinoma, Follicular / Q000201:enzymology* / Q000401:mortality / Q000556:secondary; D000236:Adenoma / Q000201:enzymology / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000201:enzymology* / Q000401:mortality / Q000473:pathology; D013965:Thyroidectomy
D014408:Biomarkers, Tumor; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human