Clinically relevant fatigue in recurrence-free prostate cancer survivors

Background: Little is known about the prevalence and associations of clinically relevant fatigue (CRF) in recurrence-free prostate cancer survivors. Patients and methods: Four hundred and sixteen recurrence-free prostate cancer survivors who were > 1 year post-radiotherapy or radical prostatectomy were surveyed. The prevalence of CRF (defined as Brief Fatigue Inventory >3) was determined and compared with a noncancer control group. Other measures included the Hospital Anxiety and Depression Scale, International Prostate Symptom Score, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire. Relationships between these factors and CRF were explored in univariate and multivariate analyses. Results: Analyzable data were obtained from 91% (377/416) of patients. The prevalence of CRF was 29% (108/377) versus 16% (10/63) in the controls (P = 0.031). CRF was more common in post-radiotherapy than in post-prostatectomy 33% (79/240) versus 22% (29/133), P = 0.024. However, when other factors (current depression, anxiety, urinary symptoms, medical comorbidities, pain and insomnia) were controlled for, previous treatment did not predict CRF. Current depression [Hospital Anxiety and Depression Scale >= 8 was by far the strongest association [odds ratio 9.9, 95% confidence interval 4.2-23.5)]. Conclusions: Almost one-third of recurrence-free prostate cancer survivors report CRF. Depression, anxiety, urinary symptoms, pain and insomnia measured at outcome are more strongly associated than type of cancer treatment previously received.