Effect of obesity on sexual functioning among gynecologic cancer patients receiving radiotherapy

Background: Both obesity and sexual dysfunction are common in gynecologic cancer patients. We aimed to examine the effect of obesity on sexual functioning in gynecologic cancer patients receiving radiotherapy and explore the difference by obesity measures. Methods: In this secondary analysis of a prospective observational study, obesity was measured by body mass index (BMI) and body fat percentage (BFP). BFP was estimated using the Clinica Universidad de Navarra-Body Adiposity Estimator. Sexual functioning and physical and emotional well-being were assessed pre-radiotherapy by Female Sexual Function Index and Functional Assessment of Cancer Therapy-General. Sexual functioning was reassessed at six months post-radiotherapy. We used generalized linear models to examine the effect of obesity on sexual functioning and mediation analysis to identify the indirect effect of obesity on sexual functioning through physical and emotional well-being. Results: The 54 eligible gynecologic cancer (24 cervical and 30 endometrial) patients were Black (48.1%), in a married/domestic partnership (51.9%), and had a history of prior treatment (59.3%). Patients without obesity reported slightly worse sexual functioning than those with obesity pre-radiotherapy (BMI-based obesity p = 0.012, BFP-based obesity p = 0.033), but regardless of obesity, patients showed extremely poor sexual functioning, which continued post-radiotherapy. After adjusting for cancer type and history of prior treatment, we found no association between obesity and sexual functioning pre-radiotherapy. However, BFP-based obesity had a negative effect on the changes in sexual functioning from pre- to post-radiotherapy (p = 0.013) while BMI-based obesity had no effect. The effect of obesity on sexual functioning was mediated by neither physical nor emotional well-being. Conclusions: Obesity, when measured by BFP, was associated with delayed recovery of sexual functioning in women with gynecologic cancer after radiotherapy. Further work with rigorous measurement of obesity could help provide definitive evidence of the association between obesity and sexual functioning in this population.