A narrative review of radiation-related malignancy in the pelvis

: Radiation therapy is a central treatment modality for the management of various pelvic malignancies and prior data has supported a relationship between radiation exposure and the development of long-term treatment sequelae. One of the most consequential long-term side effects of radiation therapy is the risk of developing a secondary malignancy. With advancements in radiotherapy delivery and a better appreciation of underlying tumor biology, additional considerations are needed when assessing the risk of radiation-mediated malignancies. Also, several adjacent normal structures within the pelvis may be affected by radiation-mediated toxicity, driven in part by acute and chronic inflammation. Depending on treatment modality and primary tumor location, various steps can be taken in radiation planning to reduce the risk of these side effects, which may negatively affect the patient’s quality of life. As cancer survivorship continues to increase, it is important to understand both the treatment and biologic variables which influence the risk of developing secondary malignancies in order to minimize the risk for treatment side effects and the late effect of secondary malignancy. Herein, we will provide an overview of secondary malignancies in the context of receiving therapeutic radiation to the pelvis and will highlight biologic considerations that may influence this risk. in rare, and direct comparisons of SMN risk in anatomically similar tumors between pediatric and adult patients are not robust enough to make definitive conclusions.