The Clinical Significance of Expression of Cyclooxygenase-2 in the Prognosis of the Papillary Thyroid Cancer

Kim, Hyung Rae; Si, Youn; Lee, Youn Soo; Kim, Jung Soo; Jeon, Hae Myung; Park, Woo Chan

Abstract

PURPOSE
It is well known that cyclooxygenase-2 (COX-2) is associated with carcinogenesis in many human cancers. In thyroid cancers, COX-2 expression in aging patients is known as a powerful prognostic factor of differentiated thyroid cancer. Therefore, in this study, we investigated the expression of COX-2 in cases of papillary thyroid cancer (PTC), as well as its association with other prognostic factors of thyroid cancer.
METHODS
A total of 213 cases of papillary thyroid cancer were enrolled in this study and their clinicopathological characteristics were investigated retrospectively by a review of medicalrecords. Immunohistochemical staining for COX-2 was performed in the malignant tissue of the cases and the resultsof were then evaluated to determine if they were associated with other prognostic factors.
RESULTS
The mean age of patients was 46 years (Range: 17~77 years old) and the tumor sizesranged from 0.1 to 5 cm (mean 1.2±0.9 cm). The pathological findings were as follows; thyroid capsule invasion in 101 patients (47%), lymph node metastasis in 76 patients (36%), multiplicity in 47 patients (22%), and bilaterality in 36 patients (17%). Positive results of immunohistochemical staining for COX-2 were noted in 131 patients (62%), however, the statistical analyses showed no significant association between COX-2 expression and other prognostic factors of papillary thyroid cancer.
CONCLUSION
No association of COX-2 expression and prognostic factors of papillary thyroid cancer were found in this study. However, a larger prospectivestudy with survival analyses would provide a better understanding of thesignificance of COX-2 expression in cases of papillary thyroid cancer.