Chronic, self-reported fatigue in adult immunotherapy patients and healthy controls: No association with...

This study examined whether cardiopulmonary exercise test (CPET) performance parameters are associated with chronic cancer-related fatigue in patients receiving immunotherapy checkpoint inhibitors (ICI) and healthy controls. Also, the differences in energy expenditure of steady-state cycling and gross efficiency were assessed during submaximal cycling efforts. This study involved patients (n = 19, 48 ± 13 years) receiving PD-1, PD-L1 checkpoint inhibitors and controls of similar age (n = 21, 49 ± 17 years). During the first visit, data on medical history, previous physical activity records, and CPET to voluntary exhaustion were collected. The second visit involved body composition assessment, the MFI-20 fatigue questionnaire, and 30-min steady-state cycling at 90% gas exchange threshold. There were no significant differences observed between the groups in age, stature, BMI, or resting blood pressure. Peak V̇O₂ was 33% lower, and the group under ICI treatment had lower cycling efficiency (22.49% vs. 20.07%, p = 0.031), compared to controls. All self-reported fatigue items derived from MFI-20 were significantly higher in the ICI group compared to controls (p = 0.001). The regression analysis found no association between the self-reported general fatigue and data collected during CPET. Patients under ICI treatment reported higher levels of chronic fatigue, lower peak V̇O₂, and reduced cycling efficiency. Interestingly, variables collected during CPET did not explain self-reported chronic fatigue, underlying the complexity of this phenomenon.