Radiation therapy was first attempted as a treatment for cancer in 1896. Since then, it has become a common modality, and the survival rate among diagnosed patients has increased drastically. While radiation can prolong life expectancy, it can be deleterious to the patients’ health. Exercise has consistently demonstrated improvement in anthropometric, cardiometabolic, and functional capacities of cancer survivors, but data concerning the effect of radiation on exercise outcomes are limited.

PURPOSE: To evaluate the effect of radiation therapy on exercise outcomes in cancer survivors.

METHODS: Patients participated in a 10-week exercise intervention involving aerobic, resistance, and flexibility training. There were 59 patients who had never used radiation (NR), 63 who had complete radiotherapy (HR), 18 currently undergoing treatment (CR),and 17 who failed to report their status. We analyzed differences among the three radiation exposure groups (NR, HR, and CR) in baseline characteristics, exercise adherence, and improvement in several parameters of health and function using chi-square and multivariate tests; post-hoc analyses tested specific group differences.

RESULTS: There were no baseline differences between groups in age, health history, body composition, cardiovascular parameters, fatigue, insomnia, or depression. Patients in the NR group performed better on the five times sit-to-stand test than HR patients (p=0.013) and better on sit-and-reach (p=0.037) and functional reach (p=0.059) than CR patients. There were no differences in program completion based on use of radiation (p=0.404). Although there were no baseline differences in the six-minute walk (p=0.987), CR patients improved more than HR patients (p=0.038) and NR patients (p=0.051). There were no baseline differences in systolic blood pressure (p=0.957) but CR patients experienced greater reductions than patients in the HR group (p=0.011) and NR group (p=0.035).

CONCLUSION: Exercise may be an effective way to mitigate some of the health consequences associated with radiation therapy. In our sample, exercise improved blood pressure and six minute walk more in patients who were currently undergoing treatment; however, our low retention rate may create potential bias and fail to accurately characterize expected results.