The effect of interleukin-33 expression on prognosis in patients with nasopharyngeal carcinoma.

Introduction: Interleukin-33 (IL-33) is a newly defined inflammatory cytokine that is a member of the interleukin-1 (IL-1) gene family. This cytokine is expressed in structural cells, such as the vascular endothelium, bronchial epithelial cells, keratinocytes, epithelial cells of the stomach, and fibroblastic reticular cells of lymphoid tissues. Several studies suggest that IL-33 plays a role in head-and-neck cancer. The aim of this study was to retrospectively examine IL-33 expression in nasopharyngeal carcinoma (NPC) and to evaluate its relationship between clinicopathological characteristics and prognosis.

Methods: In this monocentric, retrospective analysis, the data of 43 cases diagnosed with primary NPC and 20 cases with normal nasopharyngeal tissue (diagnosed between 2014 and 2020) were evaluated regarding the relationship between the immunohistochemically analyzed IL-33 expression status and corresponding clinicopathological parameters.

Results: The mean age was 56.9 years. The majority (67.4%) of the patients had an early tumor stage (T1-T2). IL-33 expression was positive in 56% of the cases. The five-year overall survival rate was 77% for all patients, 90% for the patients with positive IL-33 expression, and 55% for those without IL-33 expression (p = 0.008, univariate analysis). In multivariate analysis, IL-33 expression was shown to be the only independent prognostic marker for nasopharyngeal carcinoma (p = 0.014).

Conclusion: This retrospective study showed that IL-33 expression could be considered an independent factor affecting positively prognosis in NPC.