Objective: To assess the impact of body mass index (BMI) on radiotherapy toxicities in endometrial cancer patients.
Methods: This was a retrospective cohort study of women diagnosed with endometrial cancer between January 2006 and December 2014 at the Royal Cornwall Hospital Trust. Women who received radiotherapy as part of their treatment, including external beam radiotherapy (EBRT) and/or vaginal brachytherapy were included. Radiation-related toxicities were graded according to the Radiation Therapy Oncology Group (RTOG) guidelines. Toxicity outcomes were compared across BMI groups-non-obese (BMI <30 kg/m2) and obese (BMI ≥30 kg/m2)-according to radiotherapy treatment received (EBRT, brachytherapy or a combination).
Results: Of a total of 159 women who received radiotherapy, 110 were eligible for inclusion in the study. Sixty-three women had a BMI <30 kg/m2 and 47 women were obese. Obese women had poorer Eastern Cooperative Oncology Group performance status (P = 0.021) and more comorbidities (P < 0.001) compared to the non-obese group. Total (any) toxicity rates were 60.3, 72.7 and 52.0% for EBRT and brachytherapy (N = 63), single-mode EBRT (N = 22) and brachytherapy (N = 25), respectively. BMI was not associated with the incidence of acute and late radiation toxicities in the different radiotherapy groups, and there were no differences in individual complications between the BMI groups.
Conclusion: When comparing obese to non-obese women, obesity does not negatively impact the incidence of radiation toxicities in endometrial cancer. However, toxicities remain an important challenge as they are common and negatively influence the quality of life (QoL) of survivors. Future studies need to further explore the role of BMI and possible interventions to improve toxicities and QoL.
Keywords: Endometrial cancer; Obesity; Radiation; Toxicity.