COX-2 expression in DCIS:: correlation with VEGF, HER-2/neu, prognostic molecular markers and clinicopathological features

Aims: There is considerable evidence that links COX-2 to the development of cancer. The aim of our study was to assess, by immunohistochemistry, COX-2 expression in ductal carcinoma in situ (DCIS) and its possible correlation with HER-2/neu, vascular endothelial growth factor (VEGF) expression and other common immunohistochemical parameters (p53, ER, PGR, Ki67). Methods and results: Tissue samples of 49 archival cases of DCIS without any invasive component were analysed for COX-2, HER-2/neu, VEGF, oestrogen and progesterone receptors, Ki67 and p53 by immunohistochemistry using specific antibodies. COX-2 expression was detected in 43 (87.8%) tissue samples, of which 12 (24.5%) were graded as weak, 22 (44.9%) as moderate and nine (8.4%) as high expression. Only six (12.2%) lesions were negative for COX-2 expression. VEGF expression was detected in 93.8% of samples; 66.7% of lesions were found to be positive for HER-2/neu expression. Furthermore, COX-2 expression was significantly correlated with VEGF expression (P = 0.003). A significant positive correlation was also observed between COX-2 and HER-2/neu expression (P < 0.0001). Conclusions: Our results suggest that COX-2 is highly expressed in DCIS and takes part in the molecular pathway implicated in progression of breast cancer and may provide a rationale for targeting COX-2 in preinvasive breast cancer therapy.