Stimulated monocyte IL-6 secretion predicts survival of patients with head and neck squamous cell carcinoma

<p>Abstract</p> <p>Background</p> <p>This study was performed in order to determine whether monocyte <it>in vitro </it>function is associated with presence, stage and prognosis of head and neck squamous cell carcinoma (HNSCC) disease.</p> <p>Methods</p> <p>Prospective study describing outcome, after at least five years observation, of patients treated for HNSCC disease in relation to their monocyte function. Sixty-five patients with newly diagnosed HNSCC and eighteen control patients were studied. Monocyte responsiveness was assessed by measuring levels of monocyte <it>in vitro </it>interleukin (IL)-6 and monocyte chemotactic peptide (MCP)-1 secretion after 24 hours of endotoxin stimulation in cultures supplied either with 20% autologous serum (AS) or serum free medium (SFM). Survival, and if relevant, cause of death, was determined at least 5 years following primary diagnosis.</p> <p>Results</p> <p>All patients, as a group, had higher <it>in vitro </it>monocyte responsiveness in terms of IL-6 (AS) (<it>t </it>= 2.03; <it>p </it>< 0.05) and MCP-1 (SFM) (<it>t </it>= 2.49; <it>p </it>< 0.05) compared to controls. Increased <it>in vitro </it>monocyte IL-6 endotoxin responsiveness under the SFM condition was associated with decreased survival rate (Hazard ratio (HR) = 2.27; Confidence interval (CI) = 1.05–4.88; <it>p </it>< 0.05). The predictive value of monocyte responsiveness, as measured by IL-6, was also retained when adjusted for age, gender and disease stage of patients (HR = 2.67; CI = 1.03–6.92; <it>p </it>< 0.05). With respect to MCP-1, low endotoxin-stimulated responsiveness (AS), analysed by Kaplan-Meier method, predicted decreased survival (χ = 4.0; <it>p </it>< 0.05).</p> <p>Conclusion</p> <p>In HNSCC patients, changed monocyte <it>in vitro </it>response to endotoxin, as measured by increased IL-6 (SFM) and decreased MCP-1 (AS) responsiveness, are negative prognostic factors.</p