Cyclooxygenase-2 expression in thyroid neoplasms.
OBJECTIVE
Previous studies have demonstrated that cyclooxygenase-2 (COX-2) plays a role in carcinogenesis and carcinoma development. In this study, we investigated its expression in thyroid neoplasms in order to elucidate its role.


RESULTS
COX-2 expression was studied immunohistochemically in 20 anaplastic (undifferentiated) carcinomas, 49 papillary carcinomas, 22 follicular carcinomas and 15 follicular adenomas. Positive staining was only occasionally seen in normal follicles or stromal cells. COX-2 over-expression was found in only 20.0% of follicular adenomas and 40.9% of follicular carcinomas. In papillary carcinomas, the incidence (81.3%) was significantly higher (P < 0.0001) than in follicular carcinomas, although COX-2 expression was reduced in cases with old age (P = 0.0190), large size (P = 0.0028), advanced stage (P = 0.0225), satellite tumours (P = 0.0363), and the presence of solid, scirrhous or trabecular growth patterns (P = 0.0018). Undifferentiated carcinomas less frequently over-expressed COX-2 (P = 0.0004), with an incidence of 40.0%.


CONCLUSIONS
These results indicate that the up-regulation of COX-2 may contribute predominantly in the early phase of papillary carcinoma progression, whereas it plays a more adjuvant role in follicular carcinoma progression.
Ito
Y
Y
Kuma Hospital, Chuo-ku, Kobe, Japan. ito01@kuma-h.or.jp
Yoshida
H
H
Nakano
K
K
Takamura
Y
Y
Miya
A
A
Kobayashi
K
K
Yokozawa
T
T
Matsuzuka
F
F
Matsuura
N
N
Kuma
K
K
Miyauchi
A
A
D002277:Carcinoma / Q000201:enzymology* / Q000556:secondary; D051546:Cyclooxygenase 2; D006801:Humans; D007124:Immunoenzyme Techniques; D007527:Isoenzymes / Q000378:metabolism*; D008565:Membrane Proteins; D008875:Middle Aged; D009367:Neoplasm Staging; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000201:enzymology* / Q000473:pathology; D015854:Up-Regulation
D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases