Expression of oestrogen receptor β and prognosis of colorectal cancer

BACKGROUND: Previous studies suggest that sex steroids influence colorectal cancer (CRC) carcinogenesis. The oestrogen receptor beta (ER beta) is the predominantly expressed ER in the colon and loss of ER beta in CRC has been associated with advanced cancer stages. METHODS: Information on vital status by the end of 2009 was obtained for 1262 CRC patients recruited between 2003 and 2007. The ER beta expression was immunohistochemically measured and associations of ER beta scores with overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS) were evaluated using Cox proportional hazard models adjusted for prognostic factors, such as tumour stage and second primary tumours. RESULTS: Of the 1101 tumour samples with successful measurement, 535 were ER beta negative (48.6%), 381 (34.6%) showed moderate and 185 (16.8%) showed high ER beta expression. Compared with high ER beta expression, lack of ER beta was associated with higher cancer stages as well as greater tumour extent. In multivariate analyses, ER beta negativity was associated with an increased hazard ratio for death (HR = 1.61, 95% CI 1.09-2.40, P = 0.02), death attributed to CRC (HR = 1.54, 95% CI 0.99-2.39, P = 0.06) as well as a poorer DFS (DFS HR = 1.64, 95% CI 1.23-3.36, P = 0.04). The associations were stronger in stage I-III patients (OS HR = 2.20, 95% CI 1.28-4.06, P = 0.007, DSS HR = 2.38, 95% CI 1.20-5.39, P = 0.02, respectively). CONCLUSIONS: Lack of ER beta expression is associated with advanced cancer stages and independently associated with poor survival. British Journal of Cancer (2012) 107, 831-839. doi: 10.1038/bjc.2012.323 www.bjcancer.com Published online 24 July 2012 (C) 2012 Cancer Research UK