<title>Effects of surgery, immunization, and laser immunotherapy on a non-immunogenic metastic tumor model</title>

Abstract

Traditional local cancer treatment modalities include surgery and radiation, which has the immediate tumor response due to tumor removal or radiation induced cell death. However, such therapeutic approaches usually do not result in eradiation of tumors, particularly when treating metastatic tumors. In fact, local treatment of primary tumors may stimulate the growth and spread of remote metastasis. Commonly used systemic therapies include chemotherapy and immunotherapy, which target the dividing cells or the immune systems. However, in addition to the severe side effects, chemotherapy often suppresses the immune systems, hence lessening the host's ability to fight the disease. Immunotherapy, on the other hand, aims at educating and stimulating immune systems using either general immune enhancements or antigen-oriented specific immune stimulation. However, so far, the traditional immunotherapy has yielded only limited success in treating cancer patients. A different approach is needed. To combine the advantages of both local therapies for acute and targeted treatment responses and the systemic therapies for stimulation of the immune systems, laser immunotherapy was proposed to use selective photothermal therapy as the local treatment modality and the adjuvant-assisted immunotherapy for systemic control. Laser immunotherapy has show positive results in treating metastatic tumors. In this study, we conducted a comparative study using surgery, freeze-thaw immunization and laser immunotherapy in the treatment of metastatic rat mammary tumors. Our results showed that removal of the primary tumors was unsuccessful at changing the course of tumor progression. The tumor cell lysate immunization delayed the emergence of metastases but did not provide immunity against the tumor challenge. Laser immunotherapy, on the other hand, resulted in regression and eradication.