ERβ as a Prognostic Factor for Colorectal Cancer Liver Metastasis

Estrogen plays an important role in the development of some cancers. However, previous studies on the influence of estrogen on colorectal cancer (CRC) have had conflicting conclusions, and there have been few reports on estrogens and liver metastasis. The aim of this study was to explore the prognostic impact of estrogens on CRC with liver metastasis. Eighty-six patients with CRC including 43 synchronous liver metastases were studied. Estrogen receptor β (ERβ) levels were assayed by immunohistochemistry in liver metastasis, CRC and adjacent normal tissues. Serum estrogen levels were measured by radioimmunoassay. The correlation between staining, clinicopathological parameters, and prognostic power were analyzed statistically. Significant differences were found in ERβ expression between liver metastasis (P = 0.012) and CRC (P = 0.002) compared to adjacent normal tissues. Serum estrogen levels in patients with liver metastases were significantly lower than those without liver metastasis (P = 0.012). The 1-, 2-, 3and 5-year survival rates were 80%, 40%, 33% and 22%, respectively for the 43 patients with liver metastasis; and 94%, 63%, 49% and 49%, respectively for patients with positive ERβ in liver metastasis tissues, and 68%, 21%, 21% and 10%, respectively for those with negative ERβ (log-rank; P = 0.018). Cox regression test showed that ER beta (P = 0.029) were detected as the independent prognostic factors for liver metastasis of colorectal cancer. In conclusion, the present study suggests that ERβ may be a prognostic factor for synchronous liver metastasis of colorectal cancer.