Prognostic impact of ERβ and MMP7 expression on overall survival in colon cancer

Estrogen receptor beta (ERβ) is the most highly expressed protein in patients with colon cancer. Matrix metalloproteinase 7 (MMP7) is consistently expressed throughout cancer progression. We have previously shown that endocrine therapy can inhibit MMP7 expression in colon cancer cells. In this study, we aim to identify the prognostic effects and correlation of ERβ and MMP7 in the context of colon cancer. ERβ and MMP7 levels were assessed by immunohistochemistry in normal mucosa and tumoral tissues from 423 patients with stage I-III colon cancer. The Cox proportional hazards regression model was applied to analyze the lifetime data, including overall survival (OS) and cause-specific survival (CSS). The 5-year survival rate was significantly higher in patients with high expression of nuclear ERβ than in patients with low expression (84.3% vs. 63.9%, respectively, p < 0.05). High expression of MMP7 was related to decreased OS (72% vs. 90%, respectively, p = 0.008) and 5-year survival (86.6% vs. 88.8%, respectively, p = 0.005) compared to patients with low expression of MMP7. In the subset of patients with high expression levels of tumoral nuclear ERβ, high expression of MMP7 was related to OS and CSS among colon cancer patients with high expression of ERβ. In conclusion, our results suggest that low expression of ERβ was a risk factor in colon cancer, and high expression of MMP7 was an independent prognostic factor of ERβ-positive patients with colon cancer.