Assessment and predictors of fatigue in men with prostate cancer receiving radiotherapy and androgen deprivation therapy.

Introduction: Fatigue is a commonly reported symptom in men receiving radiation therapy and androgen deprivation therapy (ADT) for prostate cancer. Despite this, the complex mechanisms remain unclear. This study aims to investigate factors which correlate with development of fatigue.

Methods: Twenty-seven men with high-risk prostate cancer undergoing radiation therapy and 18 months of ADT were assessed for fatigue, haemoglobin (Hb), testosterone, magnetic resonance imaging (MRI) fat fraction (FF) and apparent diffusion coefficient (ADC), at baseline and at intervals after radiotherapy. Changes from baseline were analysed using paired t-tests. Linear time trends were assessed using linear mixed effect models.

Results: Overall, mean fatigue score increased from baseline to the 18-month time interval (difference 4.5, P = 0.0114). The mean value for Hb significantly decreased (P < 0.001) from baseline to 18 months. The mean value for testosterone significantly decreased (P < 0.001) from baseline to 12 months, and remained low. Mean for MRI FF showed a significant increase (P < 0.001) from baseline to 6 months. MRI ADC showed a non-significant decrease from baseline to 6 months (P = 0.4416).

Conclusion: Radiotherapy and ADT resulted in a significant increase in fatigue scores. Statistically significant changes were noted in Hb, testosterone and MRI FF and ADC, however, none were shown to have a strong association with worsening fatigue. Further investigation in a larger cohort is required to assess the interaction between fatigue and possible biological factors.