Abstract # 1780 Deconstructing cancer-related fatigue: A role for motivational deficits

Abstract

Cancer-related fatigue is a common, debilitating condition which is proposed to be associated with inflammatory mechanisms. The objective of our ongoing project is to objectively assess incentive motivation in cancer-related fatigue and its association with inflammation. Patients recruited at MD Anderson Cancer Center were tested for incentive motivation using a validated computerized task, the Effort Expenditure for Rewards Task (EEfRT). A blood sample was obtained on the same day. In a preliminary sample of 29 subjects, 15 patients with high fatigue and 14 patients with low fatigue were identified. Compared to low fatigued patients, patients with high fatigue showed an increased willingness to exert effort, reflected in overall higher percentage of high effort choices on the EEfRT (43% vs. 25%, p = .03). Whereas low fatigued patients were sensitive to changes in reward value, reflected in more high effort choices when rewards for high effort were increased (low vs. medium reward: 14% vs. 24%, p = .03; medium vs. high reward: 24% vs. 36%, p = .01), patients with high fatigue did not show this sensitivity (low vs. medium: 38% vs. 44%, p = .07; medium vs. high: 44 vs. 51%, p = .27). In conclusion, patients with high fatigue overall make high effort choices, regardless of the outcome-value of the invested effort. Markers of inflammation assessed in serum will be determined at completion of the study.