Head and neck cancer: a comprehensive review of epidemiology, global burden and advances in radiotherapy.

Abstract

Head and neck cancer (HNC), a heterogeneous group of malignancies that arising from the mucosal surfaces of the Upper Aerodigestive Tract (UADT), is a major health concern worldwide. By 2050, the number of cancer cases worldwide is expected to reach 35 million, with nearly half of all new cases and deaths occurring in Asia. In India, HNC is particularly prevalent accounting for about 30% of the global burden, with lip and oral cavity cancers (OCC) make up 10.17% of all cases, highlighting a serious public health crisis. A comparative analysis of GLOBOCAN 2022 data reveals a significant variation in HNC burden; India's overall Age-Standardized Incidence Rate (ASIR) for lip and OCC is 9.8, which is considerably higher than the Asian average of 3.2 and the global average of 4.1. Indian males facing a particularly high burden (ASIR: 14.7) compared to females (ASIR: 4.9). While India leads in sites such as the larynx and hypopharynx, it maintains a notably lower burden of nasopharyngeal cancer (ASIR: 0.4) compared to the rest of Asia (ASIR: 1.9). High Mortality-to-Incidence Ratio (MIR) persist across all sub-sites, with tobacco, alcohol, and Human Papillomavirus (HPV) being the main risk factors. This review critically analyses HNC literature by integrating historical perspectives with recent progress in radiation therapy (RT). This includes Three- Dimensional Conformal Radiation Therapy (3DCRT), Intensity- Modulated Radiation Therapy (IMRT), Image Guided Radiation Therapy (IGRT), Volumetric Modulated Arc Therapy (VMAT), and new methods like Stereotactic Radiosurgery (SRS), Stereotactic Radiotherapy (SRT), Stereotactic Body Radiation Therapy (SBRT), Tomotherapy, Proton therapy (PT) and Adaptive Radiotherapy (ART). Radiotherapy remains a cornerstone of treatment, with its success relying on precise technology and accurate treatment delivery. By analysing epidemiology, risk factors, and evolving clinical approaches, this work creates a clear framework for current management and highlights future directions to improve patient quality of life and treatment results.