Head And Neck Squamous Cell Carcinoma (HNSCC)

Head and Neck Squamous Cell Carcinoma (HNSCC) originates in the moist, mucosal linings of the head and neck, including the oral cavity, pharynx, larynx, and sinuses. These aggressive tumors develop from flat squamous epithelial cells that undergo uncontrolled proliferation due to genetic mutations in tumor suppressors like TP53, CDKN2A, and NOTCH1. Globally, HNSCC affects over 800,000 people annually, ranking as a leading cancer with high morbidity.?

Risk Factors and Causes

Major risks include tobacco use, heavy alcohol consumption, and human papillomavirus (HPV) infection, particularly HPV-16 in oropharyngeal cases. Betel nut chewing is prevalent in regions like India, while environmental factors like EBV contribute to nasopharyngeal variants. Genetic instability, epigenetic changes such as DNA hypermethylation, and field cancerization—where the entire mucosa is predisposed—drive progression from hyperplasia to invasive carcinoma.?

Progression and Symptoms

HNSCC advances through stages: hyperplasia, dysplasia, carcinoma in situ, and invasion, often involving chromosomal losses (e.g., 9p21) and amplifications (e.g., CCND1). Symptoms include persistent mouth sores, sore throat, hoarseness, dysphagia, ear pain, and neck lumps from lymph node spread. Metastasis to lungs worsens prognosis, with 5-year survival around 50%.?

Treatment Approaches

Standard care combines surgery, radiotherapy, and chemotherapy, with immunotherapy like pembrolizumab for advanced cases. Targeted therapies address EGFR overexpression. Early detection improves outcomes, though recurrence and resistance remain challenges in this heterogeneous disease.?