Association Between Interleukin-6 and Head and Neck Squamous Cell Carcinoma: A Systematic Review

Interleukin-6 (IL-6) is a proinflammatory cytokine which plays an important role in several regulatory mechanisms of cancer. Moreover, experimental and clinical studies have reported that IL-6 targeted therapies might provide significant benefits for cancer treatment. The purpose of this systematic review is to evaluate IL-6 activity in patients with head and neck squamous cell carcinoma (HNSCC). A systematic review of the association between serum, saliva and tumor IL-6 and HNSCC was developed on PubMed/Medline in the publication range from January 1995 to January 2019. Our literature analysis demonstrated that overexpression and elevated serum and/or saliva IL-6 concentrations in patients with HNSCC are related to poor survival and oncological outcomes. Although there is a correlation between IL-6 concentrations and tumorigenicity, it is noteworthy that IL-6 targeted therapies are generally performed in vitro and in experimental studies. Therefore, prospective, randomized clinical trials are required that focus on IL-6 targeted therapies for the treatment of HNSCC.