Abstract. Despite the development of novel multimodal treatment combinations in advanced oropharyngeal squamous cell carcinoma (OSCC), outcomes remain poor. The identification of specifically validated biomarkers is required to understand the underlying molecular mechanisms, to evaluate treatment efficiency and to develop novel therapeutic targets. The present study, therefore, examined the presence of aldehyde dehydrogenase family 1 member A1 (ALDH1A1) and high mobility group box 1 (HMGB1) expression in primary OSCC and analyzed the impact on survival time. In 59 patients with OSCC, the expression of ALDH1A1, p16 and HMGB1, and their clinicopathological data were analyzed. HMGB1 positivity was significantly increased in patients with T1-2 stage disease compared with T3-4 stage disease (P<0.001), whereas ALDH1A1 positivity was not. ALDH1A1 + tumors showed significantly lower differentiation than ALDH1A1 -tumors (P=0.018). Multivariate analysis showed that ALDH1A1 positivity (P=0.041) and nodal status (N2-3) (P=0.036) predicted a poor prognosis. In this patient cohort, ALDH1A1 and nodal status were identified as independent predictors of a shorter overall survival time. The study results, therefore, provide evidence of the prognostic value of ALDH1A1 as a marker for cancer stem cells and nodal status in OSCC patients.
IntroductionHead and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with an annual incidence of 500,000 new cases and 200,000 mortalities (1,2). Oropharyngeal squamous cell carcinoma (OSCC) is a subtype of HNSCC arising from the oropharynx, which includes anatomically the base-of-the tongue, the tonsils, the soft palate and the side and back wall of the throat. The incidence rates for cancer sites in the oropharynx, such as the tonsils and the base of the tongue, are associated with a rise in human papilloma virus (HPV) infections, but a decreased number of tobacco-and alcohol-related cancers (3). In recent decades, there have been a number of important advances in the standard treatment of HNSCC, including surgical innovations for early-stage tumor patients and novel multimodal treatment combinations for more advanced-stage tumors, such as surgery followed by adjuvant radiotherapy (RT) or chemoradiotherapy (CRT), or CRT alone (4). However, outcomes remain poor in advanced tumor stages due to frequent local and regional metastases, and resistance to therapy (5,6). Therefore, identification of specific validated biomarkers is required to understand the underlying molecular mechanisms, evaluate treatment efficiency and develop novel therapeutic targets.High mobility group box 1 (HMGB1) is a nuclear, non-histone, chromatin-binding protein (7) that has been implicated in the activities of various cell type, including enterocytes, cardiomyocytes, pituicytes, macrophages and monocytes (8-11). HMGB1 is defined as one of the damage-associated molecular pattern molecules that interact with a variety of pattern recognition receptors in the microenvironment of damaged or necrot...