Association between cancer-related fatigue and other symptoms in breast cancer patients.

Abstract

e20526 Background: Cancer-related fatigue (CRF) is one of the most prevalent side effects of cancer treatment and has a detrimental effect on a patient’s normal functioning and quality of life. At present, the underlying pathophysiology of CRF is poorly understood, as it is complex phenomenon involving the interaction of many factors. The relative contributions of the disease itself, different cancer therapies, and comorbid conditions (e.g., sleep disorders, nausea) remain unclear. Therefore, it is important to understand the association between them in order to develop better strategies for the prevention and treatment of CRF. Methods: The purpose of these secondary analyses was to examine the association between post-treatment fatigue with disturbed sleep (on a 0–10 scale), delayed nausea (on a 1–7 scale), age, and baseline fatigue. Analyses were performed on 541 breast cancer patients (mean age 54, 100% female) who completed a four-day diary assessing nausea and sleep following initial chemotherapy. Fatigue as its worst during the prior week (0 = no fatigue to 10 = fatigue as bad as you can imagine) was assessed both prior to chemotherapy and on Day 4. To determine associations between variables, Pearson’s correlation analysis and linear regression were performed. Results: Post-treatment CRF was significantly associated with baseline fatigue (r = 0.40, p < 0.0001), disturbed sleep (r = 0.45, p < 0.0001), delayed nausea (r = 0.37, p < 0.0001), and age (r = -0.22, p < 0.0001). Linear regression showed that a one unit increase in baseline fatigue, disturbed sleep, and delayed nausea was associated with increase in post-treatment CRF by 0.29, 0.37, and 0.42, respectively, all p’s < 0.0001. In addition, every ten years of increased age was associated with a decrease in post-treatment CRF by 0.33 (p < 0.0013). Conclusions: Post-treatment fatigue was found to be significantly correlated with baseline fatigue, disturbed sleep, and delayed nausea while negatively correlated with age in patients with breast cancer. These results demonstrate the importance of further research to better understand the underlying psychological and biological mechanisms for CRF in order to develop effective treatments. Supported by NCI grant CA37420.