The influence of polymorphisms in cytokine genes on pain and response to palliative radiotherapy in multiple myeloma patients: prospective observational study

Abstract

**Objectives:** The aim of this study was to assess the impact of polymorphisms in cytokine genes on pain severity and pain treatment with palliative radiotherapy. **Methods:** 81 patients were enrolled. Pain severity and dose of analgesics were evaluated prior to radiotherapy and at 4, 12 and 24 weeks following treatment. The study analysed 12 gene polymorphisms of 6 cytokines (IL-6, IL-10, TNFα, IL-1α, IL-1β, IL-1RA) involved in the pathogenesis of pain syndrome. **Results:** Association between severe pain and patients' variables and genotype groups of each cytokine gene studied were analysed. Karnofsky index ≥ 60 % and IL1RN rs2234677 polymorphism GG genotype were found to have significant impact on severe pain prior to radiation. Patients with IL-1α encoding gene IL1A rs1800587 CC genotype and patients with IL-1β encoding gene IL1B rs1143634 CC genotype had significantly better response to radiotherapy. Patients with IL-1RA encoding gene IL1RN rs315952 CC genotype had a faster response to radiation. **Conclusions:** Findings of this study emphasize the importance of gene polymorphisms which encode inflammatory interleukins in the severity of pain and response to palliative radiotherapy. Regional research ethical committee number BE-2-39 ClinicalTrials.gov registration number NCT02024815.