Radiotherapy induced secondary malignancies

– Radiation therapy is an integral part of oncology treatments, and almost half of the patients receive radiation as a curative or palliative treatment. Thanks to modern oncology strategies survival period is getting longer, how-ever, approx. one-fifth of patients also experiences the development of second tumor. According to recent studies, oncological treatment itself may be associated with the development of a secondary tumor. It is estimated that 5-8% of such cases may be due to radiotherapy. It is a major challenge to understand the effects of radiotherapy on accidentally surviving tumor cells, healthy tissues surrounding the tumor, low-dose areas, and non-irradiated tissues, where abscopic effects may occur and may be collectively responsible for the so-called radio carcinogenesis. Recently, a number of studies address the tumor-inducing effects of radiation therapy. This review is intended to summarize our knowledge of the subject in terms of pathogenesis, radiogenomics, and radiophysical and radiobiological aspects, as well as prevention and screening options.

Radiation therapy represents a double-edged sword: on the one hand it can be effectively used in the curative treatment of cancer, on the other hand, however, it can potentially induce a secondary tumor that occurs years later. Based on the above considerations only maximally optimized and personalized radiation therapy can be justified in the future.