Gharib_2025_Discov.Oncol_16_2046

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) significantly impairs critical functions such as speech, swallowing, and breathing, often resulting in disfigurement and a substantial decline in quality of life. Despite advances in treatment, the 5-year survival rate remains approximately 60-65%. This study aimed to assess the impact of induction chemoradiotherapy on organ preservation in HNSCC and to explore the potential role of DPP7 as a diagnostic and prognostic biomarker. METHODS: A total of 104 patients with locally advanced, non-metastatic HNSCC were enrolled in the study. Induction chemotherapy comprising three cycles of docetaxel, cisplatin, and fluorouracil (TPF) was followed by concurrent chemoradiotherapy. DPP7 expression was analyzed in HNSCC tissues using quantitative reverse transcription PCR (qRT-PCR) and in patient serum through enzyme-linked immunosorbent assay (ELISA). RESULTS: Induction chemotherapy achieved a complete response (CR) rate of 16.4% and a partial response (PR) rate of 36.5%. Following radiotherapy, the CR rate increased to 59.1%, with 15.9% of patients achieving substantial partial responses. DPP7 expression was significantly elevated in HNSCC tissues and serum compared to normal controls (p < 0.0001). High DPP7 levels correlated with adverse clinical characteristics, including advanced age, female sex, poor tumor differentiation, and higher clinical stage (all p < 0.0001). DPP7 expression increased significantly with worsening response (p < 0.0001) in both tissue and serum, from lowest in CR to highest in progressive disease (PD). Multivariate analysis identified DPP7 as an independent prognostic biomarker, and its strong presence in serum highlights its potential for non-invasive risk stratification. Elevated expression was significantly associated with reduced overall and disease-free survival (p < 0.005). CONCLUSION: This study suggests that patients with HNSCC can achieve favorable response and organ preservation rates through induction chemoradiotherapy. Furthermore, DPP7 appears to be a potential biomarker of clinical interest; its expression increased significantly with worsening response (p < 0.0001) in both tissue and serum. Elevated DPP7 levels in tissue and serum correlate with adverse clinical features and reduced survival outcomes. These findings highlight the potential of clinical relevance of DPP7; further validation in larger, independent cohorts is recommended to confirm its prognostic and diagnostic effectiveness.