Context: Pain, depression, and fatigue are common symptoms in cancer populations. They often coexist and have been suggested as a specific symptom cluster. Systemic inflammation (SI) may be a possible common mechanism.
Objective: This study examined whether pain, depression, and fatigue exist as a symptom cluster in advanced cancer patients with cachexia and might be related to the presence of SI.
Methods: Secondary data analysis was undertaken of two clinical trials in patients with cancer cachexia (n = 654). Pain, depression, and fatigue were assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30. Plasma C-reactive protein (CRP) was measured as a marker of SI in a subgroup (n = 436). Multivariate analysis and a series of regression analyses were undertaken relating pain, depression, fatigue, and CRP.
Results: Pain, depression, and fatigue clustered, with between two and four times as many patients having all three symptoms as would be expected if the symptoms only coexist by chance (P < 0.001). CRP was not related to the symptom cluster. There was a strong relationship between the pattern of symptoms and physical functioning (P < 0.001).
Conclusion: Pain, depression, and fatigue is an identifiable symptom cluster in a cohort of cachexic cancer patients and is associated with reduced physical functioning.