To evaluate the relationship between estrogen receptor (ER) β expression and the clinicopathological characteristics and prognosis of colorectal cancer by Meta-analysis, and establish the evidence-based role of ER β in the diagnosis and treatment of colorectal cancer.

All the literature investigating ER β and colorectal cancer published in CNKI, Wangfang data, Cochrane Library, PubMed, SpringerLink, EBSCO, MEDLINE and other databases starting from the databases establishment to November 2019 were retrived. The relevant clinical data were extracted, and the literature quality was evaluated according to the Cochrane literature quality assessment manual. Meta analysis was conducted using Revman 5.3.

A total of 8 articles with 2 149 patients were included. The prognosis of patients with positive ER β expression was better (HR=0.74, 95% CI: 0.63-0.86, P=0.000 1). The expression of ER β was correlated with tumor invasion (OR=1.44, 95% CI: 1.15-1.80, P=0.002), while were not related to gender OR=1.17, 95% CI: 0.97-1.40, P=0.10), tumor differentiation (OR=0.96, 95% CI:0.78-1.20, P=0.74), lymph node metastasis (OR=0.90, 95% CI: 0.74-1.11, P=0.33), distant metastasis (OR=0.91, 95% CI: 0.67-1.23, P=0.55), the difference were not statistically significant.

ER βis an independent prognostic factor for colorectal cancer, and plays an important role in the prognosis prediction and therapeutic target for colorectal cancer.