Laser Immunotherapy: Concept, Possible Mechanism, Clinical Applications, and Recent Experimental Results

Laser immunotherapy (LIT) is an in situ autologous cancer vaccine (inCVAX) that induces a systemic immune responses through a local intervention. The effect of LIT depends on two major interactions: a selective photothermal interaction and an active immunological stimulation. The selective photothermal interaction can help release tumor antigens, which can stimulate specific antitumor immunity in the host. The elevated expression of heat-shock protein and the local application of immunoadjuvant further enhance the immune responses. The safety and effectiveness of LIT have been tested in preclinical studies and in preliminary clinical trials. Tumor samples from breast cancer patients treated by LIT were analyzed using histochemical methods. Preliminary results showed a change in T cells after LIT treatment, indicating strong induced immune responses. LIT may be proven to be a feasible treatment modality for metastatic cancers.