COX2 expression in prognosis and in prediction to endocrine therapy in early breast cancer patients

Nes, J.G.H. van; Kruijf, E.M. de; Faratian, D.; Velde, C.J.H. van de; Putter, H.; Falconer, C.; ... ; Bartlett, J.M.S. (2011)

Article / Letter to editor

In breast cancer, the prognostic impact of COX2 expression varies widely between studies. We examined the prognostic value of COX2 expression in a large cohort of breast cancer patients treated with primary surgery between 1985 and 1994 and explained the variable results of COX2 expression found in the literature. A tissue microarray was constructed of available tumour material, and ER, PgR, HER2, Ki67 and COX2 were examined by immunohistochemistry. Median follow-up was 19 years. Fifty-five percent (n = 369/677) of patients received no systemic treatment. COX2 was scored using a weighted histoscore. Analysis of COX2 expression in two groups based on the median (148; below vs. above) showed an increased hazard ratio (HR) of 1.35 (95% CI 1.05-1.75, P = 0.021) for disease-free survival (DFS) and of 1.39 (95% CI 1.03-1.82, P = 0.016) for overall survival (OS). However, COX2 did not remain independent in multivariate analysis. In patients with hormone receptor positive tumours, COX2 expression had a negative influence on outcome (low vs. high: DFS: HR 1.37, 95% CI 1.07-1.76, P = 0.013). This effect disappeared when endocrine therapy was administered (low vs. high: DFS: HR 0.93, 95% CI 0.51-1.70, P = 0.811) while it remained statistically significant when endocrine therapy was omitted (low vs. high: DFS: HR 1.48, 95% CI 1.12-1.94, P = 0.005). Our results show that COX2 plays a role in hormonal pathways. Our results can explain the results found in previously published studies.

• All authors: Nes, J.G.H. van; Kruijf, E.M. de; Faratian, D.; Velde, C.J.H. van de; Putter, H.; Falconer, C.; Smit, V.T.H.B.M.; Kay, C.; Vijver, M.J. van de; Kuppen, P.J.K.; Bartlett, J.M.S.
• Date: 2011-02-28
• Volume: 125
• Issue: 3
• Pages: 671 - 85
• DOI: doi:10.1007/s10549-010-0854-7