Interleukin‐18 (IL‐18) is equally expressed in inflammatory breast cancer and noninflammatory locally advanced breast cancer: A possible association with chemotherapy response

Aim Inflammatory breast cancer (IBC) is the most aggressive form of locally advanced breast cancer. The signs of inflammation such as hyperemia and hyperthermia might suggest the possible participation of inflammatory mediators. This study investigates stromal and tumor expression of nuclear factor-kappa B (NF-κB) and interleukin-18 (IL-18) in samples obtained from IBC and noninflammatory locally advanced breast cancer (LABC) and the influence of these markers on patients' prognosis. Methods Demographic data, tumor molecular characteristics and overall survival in both groups were also assessed. Furthermore, in this study, we evaluated the expression of IL-18 and p50 nuclear fraction of NF-κB by immunohistochemistry in specimens from IBC and LABC (T4b). Results We observed that 24.6% of women were diagnosed with IBC up to age 40. In addition, the patients with IBC showed a lower overall survival when compared to LABC. In regard to molecular markers, ER+, C-erbB2− or triple negative IBC patients showed a significantly reduced overall survival. In addition, a higher IL-18 immunostaining in stroma of IBC and LABC was observed in comparison with tumor cells, but stromal immunoexpression was similar between IBC and LABC. Besides, IL-18 positivity seemed be related with a better clinical response to neoadjuvant chemotherapy. However, NF-κB expression was identical in both groups. Conclusion The IL-18 is present in tumor stroma of IBC and LABC and seems to be associated with the complete response to neoadjuvant chemotherapy.