Estrogen receptor beta (ERβ) in esophageal cancer - a systematic review and meta-analysis

Background: Esophageal cancer is the eighth most common cause of cancer-related deaths worldwide. There are two main histological subtypes of esophageal cancer: adenocarcinoma and squamous cell carcinoma. Among the factors associated with the development of esophageal cancer, estrogen receptor beta (ER beta) has been found to have a clinical significance. Aim: To investigate the relationship between ER beta expression and esophageal cancer. Methods: English Medical literature searches were conducted for ER beta expression in patients with esophageal cancer versus healthy controls. Searches were performed up to August 31, 2023, using MEDLINE, PubMed, Embase and Google Scholar. Meta-analysis was performed by using Comprehensive meta-analysis software (Version 4, Biostat Inc., Englewood, NJ, USA). Pooled odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated. Heterogeneity was evaluated using Cochrane Q-test, and it was considered present if the Q-test P value was less than 0.10. I2 statistic was used to measure the proportion of inconsistency in individual studies, with I-2 > 50% representing heterogeneity. We also calculated a potential publication bias. Results: Ten studies representing 11 substudies were selected according to the inclusion criteria. The odds ratio of ER beta expression in fixed effect analysis was 0.448, 95% CI: 0.237 to 0.846, 55.2% lower in esophageal cancer than in normal mucosa. Heterogeneity and inconsistency were low, and no publication bias was demonstrated. Conclusion: This meta-analysis showed that ER beta expression is lower in esophageal cancer biopsy specimens than in healthy controls, this finding may have a significant effect on survival and can lead to new therapeutic avenues.