Cancer immunoedition modified by low-level ionizing radiation

International Conference on Medical Physics

August 03-05, 2015 Birmingham, UK

Marek K Janiak

Posters-Accepted Abstracts: J Nucl Med Radiat Ther

Abstract :

The cancer immunoediting hypothesis, put forward at the beginning of the 21st century by Robert Schreiber and his coworkers, assumes that the immune system not only protects the host against the development of primary cancers, but also contributes to tumor progression. In fact, in the course of three consecutive phases of cancer immunoediting called elimination, equilibrium, and escape, tumor cells progressively become invisible or resistant to elimination by the immune system. Thus, the long-debated cancer immuno surveillance theory has now been incorporated as an integral part of the general concept of cancer immunoedition. During the recent twenty or so years experimental evidence has also accumulated indicating that exposures to low-level ionizing radiation (LLR, i.e., <0.1 Gy absorbed within a short time and < 0.1 mGy/min. dose rate during a protracted exposure) attenuate the development and growth of both primary and metastatic neoplasms, the effect being often associated with stimulation of anti-cancer immunity. In the present review, the LLR-induced modifications of various functions of the immune system pertinent to tumor development will be tracked and commented in relation to different phases of the cancer immunoediting process. This will likely update a basis for employment of exposures to LLR (alone or as an adjuvant to conventional therapeutic modalities) aimed at targeting the equilibrium and escape phases of cancer immunoediting in order to restore the efficacy of anti-tumor functions of the immune system, the most potent natural guardian against neoplasia.