The Current and Future Promises of Combination Radiation and Immunotherapy for Genitourinary Cancers

SIMPLE SUMMARY: Contemporary immunotherapy agents have recently been approved for use in genitourinary malignancies. Combining immunotherapy with radiotherapy may have a synergistic effect in treating bladder and prostate cancer. This article reviews the available data on combination immunotherapy and radiotherapy in the treatment of prostate and bladder cancer. ABSTRACT: As the indications for the use of immunotherapy in genitourinary malignancies expand, its role in combination with standard or conventional therapies has become the subject of contemporary studies. Radiotherapy has multiple immunomodulating effects on anti-tumor immune response, which highlights potential synergistic role with immunotherapy agents. We sought to review the body of published data studying the combination of immunotherapy and radiotherapy as well as the rationale for combination therapy. Trial information and primary articles were obtained using the following terms “immunotherapy”, “radiotherapy”, “prostate cancer”, and “bladder cancer.” All articles and trials were screened to ensure they included combination radiotherapy and immunotherapy. The effects of radiation on the immune system, including both immunogenic and immunosuppressive effects, have been reported. There is a potential for combinatorial or synergistic effects between radiation therapy and immunotherapy in treating bladder and prostate cancers. However, results from ongoing and future clinical trials are needed to best integrate immunotherapy into current standard of care treatments for GU cancers.