Introduction-Aim: Cyclooxygenase (COX) is the rate limiting enzyme that catalyzes the conversion of arachidonic acid to prostaglandins. The inducible form, COX-2, is known to be overexpressed in breast cancer. Moreover, Peroxisome Proliferation-activated receptors γ (PPARγ) are nuclear receptors, the activation of which has been related to a less malignant phenotype in various carcinomas. In the present study, we examined the expression of COX-2 in invasive breast carcinomas and its correlation with the classic clinicopathological prameters, the disease-free and overall survival of the patient and the biological markers topoIIa, c-erbB-2, p53 and PPARγ.

Materials and Methods: We applied immunohistochemistry on paraffin-embedded sections of 175 invasive breast carcinomas in order to detect the proteins COX-2, ER/PR, topoIIa, c-erbB-2, p53 and PPARγ proteins. The results were elaborated by statistical analysis. Results: COX-2 was inversely correlated with histological and nuclear grade (p=0.039 and p<0.0001 respectively) and positively with PR and ER (p=0.016 and p=0.076 respectively). COX-2 was also inversely associated with topoIIα (p=0.033) and p53 (p=0.002) and positively correlated with PPARγ (p<0.0001), whereas inverse was found the correlation between COX-2 of tumor stromal cells and c-erbB- 2. No correlation between COX-2 and patients' survival was found.

Conclusions: According to our results COX-2 is associated with a favourable prognostic phenotype, through its inverse correlation with the histological and nuclear grade, topoIIα, c-erbB-2, p53 and the parallel correlation with ER/PR and PPARγ. However, as far as the patients' survival is concerned, no prognostic value of COX-2 was found in the present study.

Key words: Cyclooxygenase-2 (COX-2), PPARγ, immunohistochemistry, breast cancer.

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