Purpose: To determine whether COX-2 expression is associated with clinicopathological parameters, including c-erb-B2 overexpression and angiogenesis, and the disease-free survival of patients with operable breast cancer.
Materials and methods: Paraffin-embedded tissue samples were selected from 205 patients surgically resected for breast cancer, between 1991 and 1997, and followed-up for at least 4 years. Samples were immunohistochemically stained with antibodies to COX-2, c-erb-B2 and CD34.
Results: COX-2 and c-erb-B2 expressions were detected in 118/205 (57.6%) and 58/205 (28.3%) patients, respectively. COX-2 expression was significantly higher in c-erb-B2 positive than c-erb-B2 negative tumors (75.9% vs. 49.7%, p-value 0.001). COX-2 expression was positively correlated with microvessel count (13.3+/-8.0 vs. 6.6+/-7.0, p-value 0.050), but not with other clinicopathological characteristics, including tumor size, involved axillary lymph nodes and estrogen or progesterone receptor status. Although COX-2 expression itself was not a prognostic marker, breast cancer patients with tumors that co-expressed both COX-2 and c-erb-B2 had a poorer 5-year disease-free survival rate than those that did not (60.2% vs. 78.3%, p-value 0.0527).
Conclusion: Our data suggest that COX-2 expression occurs frequently in c-erb-B2 positive breast cancer, and co-expression of COX-2 and c-erb-B2 may be a useful prognostic marker in patients with operable breast cancer.
Keywords: Angiogenesis; Breast neoplasm; Cyclooxygenase-2; c-erb-B2.