ABSTRACT
Biliary tract cancer has insidious onset and high degree of malignancy, and radical resection is often impossible when it is diagnosed.Conversion therapy can achieve tumor downgrading, so that patients who were initially unresectable have a chance to achieve R0 resection.However, due to the high heterogeneity and complex immune microenvironment of biliary tract cancer, conversion therapy is still in the stage of active exploration.As a new type of conversion therapy, combination of targeted therapy and immunotherapy is of great significance to effectively improve the efficiency of conversion therapy.Further exploration of combination mechanism and improvement of immune microenvironment are expected to become the future direction of combination of targeted therapy and immunotherapy.