The Role of Inflammation in the Pain, Fatigue, and Sleep Disturbance Symptom Cluster in Advanced Cancer

Abstract

<div class="section"> <a class="named-anchor" id="S1"> <!-- named anchor --> </a> <h5 class="section-title" id="d3190652e143">Context</h5> <p id="P1">Symptom researchers have proposed a model of inflammatory cytokine activity and dysregulation in cancer to explain co-occurring symptoms including pain, fatigue, and sleep disturbance. </p> </div><div class="section"> <a class="named-anchor" id="S2"> <!-- named anchor --> </a> <h5 class="section-title" id="d3190652e148">Objectives</h5> <p id="P2">We tested the hypothesis that psychological stress accentuates inflammation, and that stress and inflammation contribute to one's experience of the pain, fatigue, sleep disturbance symptom cluster (symptom cluster severity, symptom cluster distress) and its impact (symptom cluster interference with daily life, quality of life). </p> </div><div class="section"> <a class="named-anchor" id="S3"> <!-- named anchor --> </a> <h5 class="section-title" id="d3190652e153">Methods</h5> <p id="P3">We used baseline data from a symptom cluster management trial. Adult participants (N=158) receiving chemotherapy for advanced cancer reported pain, fatigue and sleep disturbance upon enrollment. Prior to intervention, participants completed measures of demographics, perceived stress, symptom cluster severity, symptom cluster distress, symptom cluster interference with daily life, and quality of life (QoL), and provided a blood sample for 4 inflammatory biomarkers (IL-1β, IL-6, TNF-α, CRP). </p> </div><div class="section"> <a class="named-anchor" id="S4"> <!-- named anchor --> </a> <h5 class="section-title" id="d3190652e158">Results</h5> <p id="P4">Stress was not directly related to any inflammatory biomarker. Stress and TNF-α were positively related to symptom cluster distress, although not symptom cluster severity. TNF-α was indirectly related to symptom cluster interference with daily life, through its effect on symptom cluster distress. Stress was positively associated with symptom cluster interference with daily life, and inversely with QoL. Stress also had indirect effects on symptom cluster interference with daily life, through its effect on symptom cluster distress. </p> </div><div class="section"> <a class="named-anchor" id="S5"> <!-- named anchor --> </a> <h5 class="section-title" id="d3190652e163">Conclusion</h5> <p id="P5">The proposed inflammatory model of symptoms was partially supported. Investigators should test interventions that target stress as a contributing factor in co-occurring pain, fatigue, and sleep disturbance, and explore other factors that may influence inflammatory biomarker levels within the context of an advanced cancer diagnosis and treatment. </p> </div>