Expression of cyclooxygenase-2 in fine-needle aspirates from breast carcinoma and benign breast diseases.

Numerous studies have demonstrated that the levels of cyclooxygenase (COX), the enzyme that catalyzes the conversion of arachidonic acid to prostaglandin H(2), and of prostaglandins are higher in various tumors and cells during inflammation than in normal tissues. The aim of the present study was to analyze whether COX-2 isoform expression was noticeably higher in fine-needle aspirates (FNA) from breast carcinoma than in FNA from fibroadenoma and fibrocystic breast tissue. COX-2 expression was detected by immunocytochemical (IC) staining and was analyzed by microscopic scoring and computer gray-scale analysis. Evaluation of COX-2 IC positivity in FNA from three groups of patients (nine with breast carcinoma, nine with fibroadenoma, eight with fibrocystic breasts) revealed high COX-2 IC positivity in the majority of patients with breast carcinoma and low or absent COX-2 IC positivity in patients with fibrocystic breast changes. In addition, low or medium COX-2 IC positivity was found in the majority of patients with fibroadenoma, only three of these patients having high COX-2 IC positivity.