Galectins in Esophageal Cancer: Current Knowledge and Future Perspectives

SIMPLE SUMMARY: The overall 5-year survival rate of esophageal cancer patients is poor. Galectins are glycan-binding proteins known to contribute to tumor initiation and progression. To get insight in the expression and potential function of galectins in esophageal cancer we performed a literature review. We found that galectins have been mainly studied in the context of esophageal squamous cell carcinoma and that galectin-1, -3, and -9 expression are most frequently reported. More research is required to provide better insights in the diagnostic, prognostic, and predictive value of galectins in esophageal cancer as well as their functional role in tumor progression ABSTRACT: Esophageal cancer is a disease with poor overall survival. Despite advancements in therapeutic options, the treatment outcome of esophageal cancer patients remains dismal with an overall 5-year survival rate of approximately 20 percent. To improve treatment efficacy and patient survival, efforts are being made to identify the factors that underlie disease progression and that contribute to poor therapeutic responses. It has become clear that some of these factors reside in the tumor micro-environment. In particular, the tumor vasculature and the tumor immune micro-environment have been implicated in esophageal cancer progression and treatment response. Interestingly, galectins represent a family of glycan-binding proteins that has been linked to both tumor angiogenesis and tumor immunosuppression. Indeed, in several cancer types, galectins have been identified as diagnostic and/or prognostic markers. However, the role of galectins in esophageal cancer is still poorly understood. Here, we summarize the current literature with regard to the expression and potential functions of galectins in esophageal cancer. In addition, we highlight the gaps in the current knowledge and we propose directions for future research in order to reveal whether galectins contribute to esophageal cancer progression and provide opportunities to improve the treatment and survival of esophageal cancer patients.