20th June 2023

Head and Neck Cancers

Overview

Head and neck cancers are typically squamous cell tumours that arise in the oral cavity, pharynx, larynx, paranasal sinuses, and nasal cavity.

Risk Factors

The main risk factor for head and neck tumours is smoking. Alcohol has also been implicated as a causative factor; the effects of alcohol and tobacco may be synergistic. Cancers of oral cavity are associated with smoking, alcohol, betel chewing practice, dietary habits, poor dental hygiene, and certain infections. Some head and neck cancers are related to occupational risk factors. Cancers in the larynx may be associated with asbestos and solvents. Nasal cavity and ethmoid sinus adenocarcinomas have been linked to occupations associated with wood dust, such as the furniture industry, sawmill work, and carpentry. Human papillomavirus infection (HPV), most commonly HPV-16, plays a role in the development of certain head and neck cancers, particularly those in the oropharynx. HPV positive tumours appear to have a better prognosis than HPV negative tumours.

Diagnosis and Management

Presentation depends on the location of the primary tumour and the extent of the disease. Common presenting features by location in head and neck cancers are listed below.

A general medical evaluation should be performed, including a thorough head and neck examination and clearly document the location and extent of the primary tumour and any clinically positive lymph nodes. Almost all patients should undergo contrast-enhanced computed tomography (CT) and/or MRI to further define the extent of local–regional disease. CXR, CT Chest and PET-CT are considered for distant metastasis.
Most head and neck malignant neoplasms (90%) arise from the surface epithelium and are squamous cell carcinoma (SCC) or one of its variants, including lymphoepithelioma, spindle cell carcinoma, verrucous carcinoma, and undifferentiated carcinoma and the remaining cases include lymphomas and a wide variety of other malignant and benign neoplasms. Generally, the management of head and neck tumours depends largely on the stage of the tumour which is determined by TNM staging. In the head and neck regions, lymph nodes are organised into levels. Level I includes the submental and submandibular areas; levels II to IV include the internal jugular vein lymph nodes; level V includes the posterior triangle. Generally, which lymph node levels are involved is predictive of the primary site. For example, lip, oral cavity, and facial skin tumours typically spread to levels I and II initially; larynx and pharynx cancers have a predilection for spreading to levels II and III.
Generally, early head and neck cancer is managed with single-modality therapy, surgery, or radiotherapy. The determinants of choice between the two are complex and multifactorial. The mainstay of treatment for locoregionally advanced head and neck squamous cell carcinoma is either surgery followed by adjuvant radiation therapy or definitive concurrent chemoradiation, reserving surgery as salvage therapy, referred to as the organ-preservation approach. Head and neck cancer treatment requires a multidisciplinary approach with medical, surgical, and radiation oncology, pathology, radiology, and supportive services including physical and occupational therapy, speech and swallow therapy, and nutrition.

Nasopharynx

Nasopharyngeal carcinomas (NPC) are common in South-East Asia and male to female ratio is 3:1. The most common site of origin for NPC is the lateral wall of the nasopharynx, especially the fossa of Rosenmüller, followed by the superior posterior wall. Viral infection (e.g. Epstein-Barr virus), genetic predisposition and environmental factors are associated with the incidence of NPC. Unilateral deafness is the most common local symptom, followed by epistaxis and nasal obstruction. Cranial nerve involvement is common in NPC and 5th nerve involvement is frequent owing to the tumour in or around the foramen ovale. Tumour in the cavernous sinus can lead to diplopia secondary to compression of the III, IV, or VI nerves. The posterior cranial nerves (IX to XII) can be involved by direct parapharyngeal spread or compression by retropharyngeal lymph nodes. The majority of patients have a metastatic neck node at presentation (70%). Radiation therapy is the treatment of choice. Neck dissection is usually only indicated for radiotherapy failures. Concurrent chemoradiotherapy with induction or subsequent chemotherapy improved survival. Stage of the disease is the most important prognostic factor in terms of survival and other prognostic features include cranial nerve palsies, involvement of skull base, advanced age, male sex, and involvement of the lymph nodes in the supraclavicular fossa.

Oropharynx

The commonest sites for malignancies within the oropharynx are the tonsil and tongue base. Initial presenting symptoms of oropharyngeal cancers are often vague and non-specific; consequently, the majority of patients who present often have locally advanced disease at the time of diagnosis. Human papillomavirus (HPV) is a prognostic marker and tumour HPV positivity is associated with substantially higher cure rates and improved survival. As with all head and neck tumours, management decisions should be made in a multidisciplinary meeting depending on the stage of the disease and the patient’s factors. Surgery and radiotherapy produce similar cure rates. As excision of the base of the tongue generally causes greater disability and because of the high risk for bilateral lymphatic involvement, radiotherapy, or chemoradiotherapy, is usually the treatment of choice.

Larynx

Male and female ratio for cancers of the larynx is 5:1. Hoarseness is the most common presenting symptom and other symptoms include dysphagia, irritation, and coughing. Airway compromise in the form of stridor, which can result from circumferential extension of subglottic carcinomas, needs urgent referral to an ENT team. Early-stage disease is generally managed with surgery or radiotherapy depending on the site of the tumour and morbidity. Induction chemotherapy may select patients with advanced carcinoma suitable for full-course radiotherapy to save the larynx. Voice rehabilitation and psychosocial support are essential for the patient who was treated surgically, particularly total laryngectomy and permanent tracheostomy.