Plasma Interleukin-6 Levels in Relation to the Severity of Pain in Cancer Patients: A Case-control Study from a Tertiary Care Centre in North East India

Abstract

Introduction: With increased levels of ferritin, C-Reactive Protein (CRP), and the proinflammatory cytokine Intrleukin-6 (IL-6) frequently seen in cancer patients, inflammation is acknowledged as a critical component in the context of cancer. For medical professionals, managing pain in cancer patients, whether from the illness or its treatment, remains a constant struggle. Aim: To compare the markers of inflammation between controls and cancer patients with pain and to correlate the degree of pain and IL-6 levels in this group of patients. Materials and Methods: The present case-control study was conducted from January 2022 to December 2022 on 45 age-matched controls and 40 cancer patients with varied levels of pain who were included in the Palliative Care Unit of a State Cancer Hospital, Guwahati, Assam, India. The intensity of pain was measured using a Numerical Rating Scale (NRS). Blood samples were taken to assess the levels of IL-6, ferritin, and CRP. The data were analysed statistically using one-way Analysis of Variance (ANOVA) and linear regression, and were presented as mean±Standard Deviation (SD). Results: Compared to controls, cancer patients had significantly higher levels of IL-6, CRP, and ferritin (p-value <0.001). Spearman’s correlation analysis revealed a positive link between pain intensity and IL-6 (p-value<0.001, r-value=0.516) and between pain and CRP (p-value=0.002, r-value=0.474) was found using Spearman’s correlation analysis. Conclusion: The study results suggest a possible role for IL-6 in cancer-related pain by indicating a clear correlation between elevated IL-6 levels and the severity of pain experienced by cancer patients. This lays the foundation for investigating IL-6 antagonists as potential painkillers for cancer patients.