Long-Term and Systemic Antitumor Effects of Laser Immunotherapy in an H22 Hepatoma Mouse Model

To evaluate the long-term and systemic antitumor effects of laser immunotherapy, combining photodynamic therapy (PDT) and glycated chitosan, in an H22 hepatoma model. Tumor inhibition, survival rate, and pathology were compared among control, PDT, and laser immunotherapy (PDT + glycated chitosan) groups (n=12). Mice cured by laser immunotherapy were rechallenged with H22 cells (10 6 and 5 × 10 6 ) to assess immune memory. Additionally, its effect on untreated tumors was investigated in a bilateral tumor model by treating only one side. Laser immunotherapy increased the cure rate from 25% (PDT alone) to 50%. Rechallenged mice exhibited delayed tumor onset, with 4 remaining tumor-free. Untreated tumors on the contralateral side also showed inhibition. Laser immunotherapy, integrating PDT and an immunoadjuvant, shows promise for cancer treatment, particularly for metastatic tumors.