Lysyl oxidase-4-like protein (LOXL4) as a tumor marker and prognosis in advanced laryngeal cancer

Introduction: Lysyl oxidase-like 4 is an amine oxidase from the lysyl oxidase family that was previously shown to be overexpressed in head and neck cancer and upregulated in response to hypoxia. The possible role of lysyl oxidase-like 4 as a tumor marker in advanced stage larynx cancer was investigated. Objective: To investigate the expression of lysyl Oxidase-Like 4 protein in advanced stage laryngeal cancer and elucidate its possible role as a tumor marker, predictor of treatment response and prognosticator. Methods: Diagnostic specimens of 72 patients treated for stage III-IV laryngeal squamous cell carcinoma were evaluated for lysyl oxidase-like 4 expression by immunohistochemistry. Results: Lysyl oxidase-like 4 expression was correlated with advanced tumor stage (p = 0.041) and better differentiation (p = 0.025) but was independent of tumor diameter (p = 0.456). Response to induction chemotherapy or the need for salvage laryngectomy were not affected by lysyl oxidase-like 4 expression (p = 0.999, p = 0.070 respectively). Increased lysyl oxidase-like 4 expression was associated with better 2 year overall survival in both univariate (p = 0.036) and multivariate analyses (p = 0.014). Conclusion: Lysyl oxidase-like 4 expression emerges with advancing stages, is lost with worsening differentiation, and may have tumor suppressive properties in larynx cancer.