A Scoping Review of Clinical Features and Mechanisms of Orofacial Pain and Headache in Patients with Head and Neck Cancer

Background: Orofacial pain (OFP) and headache are common and disabling conditions in people with head and neck cancer (HNC), although their clinical characteristics and underlying pain mechanisms remain poorly studied, leading to worse diagnosis and, thus, management. Therefore, this review aims to synthesize the literature regarding clinical features, pain descriptors, mechanisms, and assessment tools of OFP and/or headache in adults with HNC. Methods: A scoping review was conducted following the Arksey and O’Malley framework and reported using PRISMA-ScR guidelines. We searched PubMed, Embase, Scopus, and Web of Science. Quantitative and qualitative original studies were included. Data were charted and summarized using narrative synthesis. Results: Of 3647 records initially retrieved, 32 studies met the inclusion criteria. Most studies were observational and heterogeneous in design, population, and pain assessment methods. OFP was highly prevalent, with neuropathic descriptors (e.g., burning, electric shocks, tingling) reported in 13.1% to 64.5% of patients, although heterogeneity in study design and tools used to assess this potential pain mechanism was high. Pain was frequently localized at the tumor site, although pain in other regions beyond the head and neck was also reported. Pain intensity was generally moderate, although varied across studies. OFP and headache in HNC patients were often neuropathic in nature and contributed significantly to disability and reduced quality of life. Most articles lacked mechanistic classifications of pain, although some suggested that central sensitization may be involved in some patients. Conclusions: Orofacial pain and headache are prevalent, under-characterized symptoms in HNC patients. There is an urgent need for standardized assessments using validated tools to improve phenotyping and inform targeted treatment strategies.