The abscopal effect of radiation therapy

• Published in: Future oncology (London, England) Vol. 17; no. 13; pp. 1683 - 1694
• Main Authors: Craig, Daniel J, Nanavaty, Nisha S, Devanaboyina, Monika, Stanbery, Laura, Hamouda, Danae, Edelman, Gerald, Dworkin, Lance, Nemunaitis, John J
• Format: Journal Article
• Language: English
• Published: England Future Medicine Ltd 01.05.2021
• Subjects: abscopal effect; autologous tumor vaccine; immunotherapy; radiation therapy/radiotherapy; vaccines; radiation therapy/radiotherapy; autologous tumor vaccine; abscopal effect; vaccines; immunotherapy
• ISSN: 1479-6694; 1744-8301
• DOI: 10.2217/fon-2020-0994

Radiation therapy (RT) in some cases results in a systemic anticancer response known as the abscopal effect. Multiple hypotheses support the role of immune activation initiated by RT-induced DNA damage. Optimal radiation dose is necessary to promote the cGAS-STING pathway in response to radiation and initiate an IFN-1 signaling cascade that promotes the maturation and migration of dendritic cells to facilitate antigen presentation and stimulation of cytotoxic T cells. T cells then exert a targeted response throughout the body at areas not subjected to RT. These effects are further augmented through the use of immunotherapeutic drugs resulting in increased T-cell activity. Tumor-infiltrating lymphocyte presence and TREX1, KPNA2 and p53 signal expression are being explored as prognostic biomarkers. Radiation therapy works by damaging DNA, which causes cells to die. Typically, radiation therapy is used to directly affect cancer cell growth at the directed site. However, reports of cell death outside of the targeted sites have been reported. Why this occurs is not fully understood, and the mechanism is under investigation. This article reviews the current literature and proposes future directions for research.