Early diagnosis of esophageal cancer is essential for improving both the effectiveness of esophageal cancer treatment and the prognosis of patients.As a new technology for esophageal cancer early diagnosis,narrow-band imaging (NBI) enables surgeon to clearly observe the mucosa and submucosal blood vessels changes in early esophageal cancer.It has initially shown excellent application value in the early diagnosis.In particular it has obvious advantages to the ordinary white light endoscopy which is currently used in esophageal cancer early diagnosis.If combined with Lugol iodine staining,magnifying endoscopy and other diagnostic methods in clinical,NBI will have a better value in early diagnosis of esophageal.

Environmental pollution is closely linked to the occurrence and development of cancer. Chemical carcinogens are the most important environmental factors causing cancer in humans. Among them, persistent organic pollutants (POPs) are characterized by their widespread distribution, persistence, and bioaccumulation. Research on the carcinogenic effects of POPs has received considerable attention in recent years. This article reviewed the internal exposure, association with cancer risk, and potential carcinogenic mechanisms of five typical classes of POPs in the environment, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), per- and poly-fluoroalkyl substances (PFAS), brominated flame retardants (BFRs), and short-chain chlorinated paraffins (SCCPs). These five types of POPs have distinct carcinogenic mechanisms, including interfering with cell proliferation cycle, altering epigenetic inheritance, promoting oxidative stress, altering energy metabolism, and affecting immune function. The development of cancer is the result of interaction between intrinsic genetic factors and external environmental factors. In addition to focusing on how environmental POPs affect the genetic material of organisms, it is also important to consider their effects on the tumor microenvironment, including tumor immunity and angiogenesis. Understanding these effects is crucial for guiding future efforts in pollution control and precision medicine in cancer treatment.