From Immune Microenvironment to Targeted Precision Therapy: New Strategies for Treatment of Pancreatic Cancer

Pancreatic cancer is a highly lethal malignancy that is usually diagnosed at an advanced stage because of its absence of early symptoms and lack of effective screening tools. Although existing treatments (e.g., surgery, chemotherapy, and radiotherapy) can provide temporary relief, the therapeutic effect of pancreatic cancer remains limited, with major issues related to drug resistance and recurrence. In recent years, immunotherapy and targeted therapy have provided renewed hope to the treatment of pancreatic cancer. The immune microenvironment of pancreatic cancer is complex and strongly immunosuppressive. Immune cells such as tumor-associated macrophages and regulatory T cells can weaken the antitumor function of the immune system by secreting inhibitory factors, thereby enabling the tumor to evade immune surveillance. Meanwhile, immune escape is exacerbated by the infiltration of hypo-immune cells and the role of tumor-associated fibroblasts in the tumor microenvironment of pancreatic cancer. In response to these immune escape mechanisms, combining immunotherapy with targeted therapy has emerged as a focal point of current research. This review compiles the characteristics of the immune microenvironment in pancreatic cancer based on current literature, aiming to provide a basis and insights for related drug development.