Long-term fatigue based on the EORTC QLQ-C30 up to five years after radiotherapy and its trajectories in men diagnosed with non-metastatic prostate cancer in the international REQUITE study

Background Fatigue is a common symptom in cancer patients associated with impaired quality of life (QoL). Little is known about long-term fatigue trajectories in prostate cancer (PCa) patients. Methods Using the European Organisation for Research and Treatment of Cancer Quality of Life Group Core Questionnaire (EORTC QLQ-C30), 1758 men treated with radiotherapy (2014–2016) for non-metastatic PCa prospectively reported fatigue up to five years later. Associations between pre-radiotherapy characteristics and clinically important fatigue (Score: ≥39/100) two years post-radiotherapy were investigated using logistic regression. Fatigue trajectories were explored using latent class growth analysis and multinomial regression. Results About 35% (608/1758) of patients experienced clinically important fatigue at least once from the start of radiotherapy up to five years later. Two years post-radiotherapy, 14% of patients reported fatigue, which was associated with pre-radiotherapy fatigue level (OR: 8.67), self-reported diabetes (OR: 1.94), BMI (OR: 1.07), and age (OR: 1.03). Long-term fatigue was strongly linked to pain, insomnia, pelvic symptoms, functional impairments, and reduced QoL. Four fatigue trajectories were identified, characterised by low (45%), moderate (42%), elevated and decreasing (8%), and (6%) increasing mean fatigue levels. Diabetes was associated with a 6 percentage point increase in the probability of experiencing an increasing fatigue trajectory. Conclusions The findings emphasise the need for early identification of PCa patients susceptible to long-term fatigue. PCa patients with elevated pre-radiotherapy fatigue levels and diabetes may require closer monitoring in risk-stratified aftercare programmes.