Biobehavioral Correlates of Multidimensional Fatigue in Men with Prostate Cancer

The purpose of this thesis project was to 1) examine trajectories of multidimensional cancer-related fatigue (CRF) in men with prostate cancer during and after radiation treatment completion, and 2) identify biobehavioral correlates (demographic, clinical, co-occurring symptoms, and biologic [inflammatory cytokines]) for the different CRF dimensions. Data for this secondary analysis were obtained from a descriptive, longitudinal IRB-approved study investigating men with non-metastatic prostate cancer receiving radiation therapy (RT). Data were obtained from 68 participant medical records, self-report questionnaires, and blood samples. Data were collected at: baseline (T1), completion of RT (T2), 6 months (T3) and 2 years (T4) after completion of RT. Spearman Rank correlations between MFSI subscale scores and patient reported outcomes and biomarker values were computed for each time point. Most dimensions (general, physical, mental) of CRF worsened during treatment, except for emotional fatigue that improved from baseline to RT completion. After completion of RT, most dimensions of CRF improved, except for emotional fatigue which remained steady. Several biobehavioral correlates (marital status, prostate cancer risk score, anxiety, depression, pain, difficulty sleeping, and several inflammatory cytokines) were observed to be associated with different dimensions of CRF both during and post RT. Identified inflammatory cytokines were most significantly associated with the emotional and mental dimensions of CRF. The findings support that there may be unique correlates, including biologic correlates for the different dimensions of CRF.