This Protocol Focuses on the Factors That Influence Survival, the Development of Complications and the Quality of Life Based on the Treatment Received in the Group of Patients Suffering From Malignant Lesions of the Head and Neck

Head and neck cancers (HNCs) comprise a heterogeneous group of malignancies arising from the mucosal epithelium of the upper aerodigestive tract, including the oral cavity, pharynx (nasopharynx, oropharynx, and hypopharynx), and larynx. These tumors are predominantly squamous cell carcinomas (HNSCC), although salivary gland malignancies and other histologic subtypes such as neuroendocrine tumors or sarcomas are also included in this anatomical classification. Globally, HNCs account for nearly 900,000 new cases and over 400,000 deaths annually, representing a significant burden in both high- and low-income countries.

Over the past decades, improvements in diagnostic imaging (e.g., PET/CT, MRI), surgical techniques (including transoral robotic surgery \[TORS\] and transoral laser microsurgery \[TLM\]), radiotherapy modalities (e.g., intensity-modulated radiotherapy \[IMRT\]), and systemic therapies (platinum-based chemotherapy, targeted agents such as cetuximab, and, more recently, immune checkpoint inhibitors like nivolumab and pembrolizumab) have reshaped the therapeutic landscape. Nevertheless, survival outcomes remain highly variable and largely dependent on tumor site, T and N classification, extranodal extension (ENE), perineural and lymphovascular invasion, margin status, HPV status (particularly in oropharyngeal carcinomas), and patient-related factors such as age, performance status, and comorbidities.

For early-stage tumors (Stage I-II), single-modality treatment-typically surgery or radiotherapy-achieves excellent oncologic outcomes with 5-year overall survival (OS) rates ranging from 70% to 90%. In contrast, patients with locally advanced disease (Stage III-IVB), particularly with hypopharyngeal or advanced laryngeal tumors, face significantly worse prognoses, with 5-year OS rates often below 40%, despite aggressive multimodality treatment. A notable exception is HPV-positive oropharyngeal squamous cell carcinoma (OPSCC), which exhibits favorable biology and enhanced responsiveness to chemoradiation, leading to OS rates exceeding 80-90%, even in advanced stages.

Treatment planning must balance oncologic control with functional preservation. While surgical resection (with or without microvascular reconstruction) remains a mainstay for many subsites, organ-preservation protocols based on concurrent chemoradiotherapy are often preferred for tumors of the oropharynx, hypopharynx, and larynx, particularly in functionally critical areas. However, definitive chemoradiation is associated with substantial acute and late toxicities, including mucositis, dysphagia, xerostomia, aspiration, and long-term dependence on feeding tubes or tracheostomy, which may severely impact health-related quality of life (HRQoL).

In this context, robust comparative analyses of different treatment modalities-taking into account tumor subsite, stage, treatment-related morbidity, complications (e.g., graded by the Clavien-Dindo classification), and validated patient-reported outcome measures such as the EORTC QLQ-H\&N35 and the FACT-H\&N-are critical for guiding evidence-based, patient-centered care. Understanding the oncologic efficacy, complication profile, and quality of life outcomes across treatment strategies is essential to inform multidisciplinary decision-making and optimize long-term survivorship.

• Incidence and Severity of Treatment-Related Complications Classified by Clavien-Dindo Scale [Срок оценки: 5 years]