Laser immunotherapy: Novel modality to treat cancer through specific antitumor immune response

Treatment of metastatic cancer remains a great challenge and needs novel approaches. Combining a selective photothermal therapy with an active immunological stimulation, laser immunotherapy (LIT) was developed to induce systemic immune responses through local intervention. LIT consists of three major components: a near-infrared laser, a light-absorbing agent, and an immunological stimulant. Its effect relies on two major interactions: a selective photothermal interaction and an active immunological stimulation. The selective photothermal interaction can reduce the tumor burden and at the same time release the tumor antigens, which can induce specific antitumor immune response. The expression of heat shock protein and the application of immunoadjuvant further enhance the host immunity. It has been proved in pre-clinical studies that LIT could not only eradicate treated local tumors but also regress and eliminate untreated metastases at distant sites. Moreover, LIT is well tolerated and has shown to have many advantages for cancer treatment compared with other traditional modalities.