Amongst all the cancers, head and neck cancers (HNC) are probably one of the most challenging cancers to treat and the most distressing to patients since as a site, the head and neck comprises the most intricate anatomy and governs critical physiologic functions.

The areas of functional responsibility encompassed within this dense region are vision, hearing, balance, olfaction, taste, swallowing, voice, endocrine, proximity to central nervous system and most importantly, facial expressions.

Though on the surface they are seemingly closely-connected, they are most diverse and heterogeneous in terms of tumour biology, behaviour, function and outcome.

Treatment goals are balanced between cure, improved survival outcomes, and ability to tolerate treatment (due to comorbid illness), and of paramount importance is the preservation of organ function if possible. Needless to say, the possible disfigurement (cosmetic outcome) with the attended psycho-social impact of a visualised scar just adds to the overall complexity of treatment planning.

Epidemiological data suggests that the incidence of HNC constitutes for 12% of all malignancies in the world, and is the fifth most common cancer type and cause for cancer-related deaths worldwide.

According to the Singapore Cancer Registry, the most common head and neck cancer is nasopharyngeal carcinoma (NPC), which features as the eighth most common cancer amongst Singaporeans.¹

AETIOLOGY

Squamous cell carcinomas (SCC) of the upper aero-digestive tract predominate and are related to tobacco (cigarettes and smokeless tobacco) and alcohol consumption. Other histological forms are salivary gland tumours, skin cancers and sarcomas.

Established viral infections postulated to play a role in carcinogenesis are Epstein Barr Virus (EBV) in NPC, and increasingly evident is the association between Human Papilloma Virus (HPV) and oropharyngeal carcinoma (which is linked to sexual practices). HPV-positive cancer patients tend to be in contrast to the typical HNC patient – they are young, non-smokers and probably non-drinkers. Patients who are positive for HPV usually carry a better prognosis.²

Additional aetiological factors include chronic trauma from sharp teeth and illfitting dentures for oral cavity SCC.

Past medical history of head and neck radiation therapy (RT) is important to note and is a potential risk factor for second primary, relevant in Singapore for patients treated for NPC many decades ago.^3,4

‘Field cancerisation’ occurs due to the wide area of exposure to tobacco and alcohol, and can predispose to second primary as well.

Monitoring pre-malignant conditions like lichen planus, submucosal fibrosis, leaukoplakia and erythroplakia is crucial.

Family history plays a role in the detection of thyroid cancers and NPC. Research indicates that genetic components and mutations specific to Asians can impact prognosis of tongue SCC, and provides invaluable information for future targeted therapy.^{5, 6}

Head and Neck Cancers and Common Symptoms

Note: Common symptoms for all sub-sites are bleeding and blood-stained secretions/discharge.

EXAMINATION

The complete head and neck evaluation entails detailed history- taking with special attention to personal history (exposure of risk factors), general examination, and thorough local examination.

At times, specialists are so focused on scoping the dysphonic, dysphagic patient that examination of the oral cavity is cursory and lesions afflicting the soft palate, floor of mouth, and ventral tongue can be potentially missed!

A high degree of suspicion is essential since HNCs are notorious for masquerading under the blanket of benign symptoms.

Common clinical scenarios:
a. Non-healing oral ulcer – Oral cavity Ca.
b. A young patient with asymmetric tonsils – Tonsillar Ca.
c. Blocked ear unilateral tinnitus, and/or neck lump – NPC.
d. Chronic cough and hoarseness in a smoker – Laryngeal Ca.
e. Recurrent aspiration pneumonia – Hypopharyngeal Ca.
f. Globus-like symptoms in an anaemic lady – Post cricoid Ca.
g. Chronic skin lesion ulcer or pigmented lesion – sun-exposed area – basal cell carcinoma (BCC), SCC, or malignant melanoma.
h. Unexplained blood-stained discharge – ear, nose, oral cavity and pharynx – common denominator for most HNCs.

Patients are likely to present to the local GP during the first symptom, possibly during the initial stages. Early referral and intervention by the specialist is critical and can save the patient from locally advanced disease and possibly distant metastasis.

Early Identification
Recent advances suggest that given the propensity for NPC to metastasise and consequently poorer prognosis, early identification of aggressive NPC with biomarkers can be treated more aggressively.⁷

It is good practice to emphasise early follow-up visits when lesions persist. Assiduous work-up is indicated for all suspicious lesions. It is unacceptable to delay diagnosis further on account of prolonged follow-up visits to review ordered results.

Investigation
Investigations usually include local excisional or incisional biopsy, fine-needle aspiration cytology (FNAC) of the neck lump, MRI/CT-scanning of the primary site and CT chest abdomen and pelvis, and PET scans for staging and pre-treatment planning.

MANAGEMENT

As the disease progresses, management goals can swing from attempted cure to palliation. Decisions are collectively taken by a multidisciplinary team at Tumour Board Meetings. The importance of early referral warrants reiteration. The histology type, site, depth of invasion (adjacent bone or soft tissues), lymph node involvement (LN), stage, presence of previous treatment in the form of RT/surgery and anticipated response to treatment will dictate the choice of treatment to the primary site and neck if involved.

Early Stages I and II

Typically, early stages I and II usually employ single modality treatment [surgery, chemo-radiation therapy (CRT) or RT], as opposed to advanced stage requiring multimodality management. In the event that there is failure post-RT, salvage option could possibly be through surgery. Post-surgery impaired wound healing is not uncommon and can be recalcitrant; and vacuum assisted closed drain system is leading to improved outcomes.⁸

The treatment truly begins at surgery and doesn’t usually end with it. The HN surgeon plays a pivotal role at every step, during initial evaluation, diagnosis, treatment planning, and last but not least, management of relapse or recurrence.

Minimally Invasive Surgery

Noteworthy to mention is the evolution of minimally invasive surgery in the form of Transoral Robotic Surgery (TORS), specifically for resections of oropharyngeal neoplasms and selective supraglottic lesions as a favoured option over CRT.^{9, 10}

Improved outcomes are possible because of reliable oncological resection enabled by wristed instruments and superior endoscopic magnified visualisation. This eliminates the need for an external incision which results in reduction in morbidity, recovery time, and hospital stay.

The downside is the economic affordability. The service of robotic surgery for HNCs is available through the SingHealth Duke-NUS Head and Neck Centre at the Singapore General Hospital (SGH).

Multidisciplinary Care

In the evolution of HNC management, a salient landmark is multidisciplinary teamwork (MDT). The head and neck surgical- oncological team, reconstructive team, radiologists, pathologists, radiation and medical oncologists, palliative team, and finally the allied health team (dietitian, speech therapists, psychologist, physiotherapist) have collectively formed a plexus to render customised cancer care service specific to every patient.

The different specialists may have differing opinions, but are united by a common outlook and a desire to work in the best interest of the patients and improve quality of life.

GPs can call for appointments through the GP Appointment Hotline at 6436 8288.

By: Assoc Prof N Gopalakrishna Iyer, Head, SingHealth Duke-NUS Head & Neck Centre; Senior Consultant, Division of Surgical Oncology, National Cancer Centre Singapore
Dr Mahalakshmi Rangabashyam, Service Registrar, Division of Surgical Oncology, National Cancer Centre Singapore  

Assoc Prof N Gopalakrishna Iyer heads the SingHealth Duke-NUS Head & Neck Centre, and is a head and neck surgeon in National Cancer Centre Singapore and Singapore General Hospital. He has extensive experience in the surgical management of head and neck cancers, as well as surgery for benign diseases in the head and neck (including thyroid, salivary gland and skin lesions).

He is actively involved in research and leads a number of research programmes that aim to determine prognostic factors in oral cancers, identifying the cause of head and neck cancers in young people and development of novel therapeutic strategies in treating these cancers.

Dr Mahalakshmi Rangabashyam S is a Service Registrar in the SingHealth Duke-NUS Head & Neck Centre, and the Division of Surgical Oncology at the National Cancer Centre Singapore. She did her post-graduate training in Otolaryngology in India. Her area of interests are in sleep, otology and head and neck cancer.

BIBLIOGRAPHY