Overexpression of cyclooxygenase-2 is associated with a favorable prognostic phenotype in breast carcinoma.
OBJECTIVE
Cyclooxygenase (COX) is the rate-limiting enzyme that catalyzes the conversion of arachidonic acid to prostaglandins. The purpose of the present study was to investigate the involvement of COX-2 protein in breast cancer biological behavior through its correlation with the well-known clinicopathological parameters and the expression of p53, c-erbB-2, topoisomerase IIalpha (topoIIalpha) and peroxisome proliferator-activated receptor (PPARgamma) proteins, as well as its effect on patients' survival.


METHODS
We performed immunohistochemistry to detect COX-2, estrogen receptor (ER), progesterone receptor (PR), p53, c-erbB-2, topoIIalpha and PPARgamma proteins in 175 cases of invasive breast carcinomas. The results were elaborated by statistic analysis.


RESULTS
Cytoplasmic expression of COX-2 was detected in 66.9% of breast carcinoma samples and was inversely correlated with both nuclear and histological grade (p < 0.0001 and p = 0.039, respectively), whereas its association with PR was found to be positive (p = 0.016). COX-2 expression was inversely correlated with topoIIalpha and p53 (p = 0.033 and p = 0.002, respectively), whereas its association with PPARgamma was parallel (p < 0.0001). In addition, c-erbB-2 of tumor cells was inversely correlated with COX-2 in stromal cells of the tumor (p = 0.011). Neither univariate nor multivariate analysis demonstrated any association between COX-2 expression and patient overall or disease-free survival.


CONCLUSIONS
The current data suggest that increased expression of COX-2 may be related to breast carcinomas with less aggressive phenotype. This suggestion is further supported by the positive correlation between COX-2 and PPARgamma, since the latter is considered to be indicative of a less malignant phenotype of tumor cells.
Nakopoulou
L
L
Department of Pathology, Medical School of Athens University, Athens, Greece. lnakopou@cc.uoa.gr
Mylona
E
E
Papadaki
I
I
Kapranou
A
A
Giannopoulou
I
I
Markaki
S
S
Keramopoulos
A
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000201:enzymology* / Q000473:pathology / Q000601:surgery; D018275:Carcinoma, Lobular / Q000201:enzymology* / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008875:Middle Aged; D047495:PPAR gamma / Q000378:metabolism
D014408:Biomarkers, Tumor; D047495:PPAR gamma; D051546:Cyclooxygenase 2