Recent findings from investigators at the Sidney Kimmel Cancer Center at Jefferson raise potential concerns regarding adverse effects associated with a therapeutic approach that has revolutionized the field of cancer treatment — cancer immunotherapy. The findings were recently published in the International Journal of Radiation Oncology + Biology + Physics.
In immunotherapy, clinicians harness the power of the patient’s own immune system to target and destroy tumor cells. This strategy has proven remarkably successful for many types of cancer and can be combined with more traditional treatments such as irradiation or chemotherapy. Novel treatments are often accompanied by unexpected adverse effects, however, and SKCC investigators Carey J. Myers and Bo Lu, MD, PhD, therefore asked whether immunotherapy combined with traditional radiation treatment might cause new adverse effects. Using a preclinical mouse model of lung cancer, they discovered that cancer immunotherapy resulted in increased infiltration of T cells from the immune system into irradiated lung and heart tissues, leading to higher mortality in the mice treated with the combination of immunotherapy and irradiation.
These findings are significant because they raise the possibility that cancer immunotherapy, while evincing great promise, can also render healthy tissue already damaged by irradiation susceptible to further damage by activated T cells. “Our study provides a reason for caution when clinical trials are developed to combine radiotherapy and immunotherapy — an issue that must be considered in the context of many types of cancer for which immunotherapeutic approaches are currently being developed,” said Lu, Professor of Radiation Oncology at Jefferson.
Lu also noted that the new research will encourage further investigations into the underlying genetic and molecular mechanisms of the T cell infiltration, as well as the development of biomarkers to monitor the process in patients undergoing immunotherapy in combination with radiotherapy or chemotherapy. With cancer immunotherapy emerging as an exciting new weapon in the war on cancer, this study emphasizes the importance of refining the technique to maximize therapeutic benefit while minimizing harmful adverse effects in patients.