Advances of aptamers in esophageal cancer diagnosis, treatment and drug delivery.

Esophageal cancer (EC) is a common malignant tumor of the digestive tract with poor prognosis and high mortality. The early diagnosis of EC mainly depends on endoscopic diagnosis, which not only needs to bear certain economic pressure, but also needs patients to recognize the high risk factors of EC. Most EC patients are diagnosed at intermediate or late stages, often due to a lack of awareness regarding early symptoms and lifestyle-related risk factors. However, the discovery of aptamers and the development of nanocarriers bring great benefits to the diagnosis, treatment, and targeted drug delivery of EC. Aptamers or peptide aptamers as biosensors or therapeutic agents for the diagnosis or treatment of EC, aptamer-drug conjugates and aptamer-functionalized drug nanocarriers for targeted drug delivery in esophageal cancer are reviewed in this paper. In addition, we expect investigators to pay special attention to improving aptamer permeability and stability to accelerate aptamer clinical transformation. In conclusion, leveraging the high target specificity of well-selected aptamers may bring new breakthroughs in the diagnosis, treatment and drug delivery of EC.