Clinical FeaturesOncology

An Overview of Head & Neck Cancer

Written by Mr Paul Lennon, Consultant Otolaryngologist, Head and Neck Surgeon, St. James’s Hospital, Royal Victoria Eye and Ear, and Blackrock Clinic

Head and Neck cancer (HNC) is an umbrella term to describe a group of malignancies managed by physicians from a number of specialities who have subspecialised in the area. From a surgical point of view, these would usually be Otolaryngologists (ENT) and Maxillofacial (MaxFax) surgeons, but also a number of Plastic surgeons. Internationally, some Head and Neck surgeons initially train as general surgeons before subspecialising in Head and Neck cancer.

The terms mouth cancer and throat cancer are often used colloquially to describe such cancers. From an AJCC staging point of view Head and Neck cancer includes the following sites:

  • Oral cavity;
  • Nasopharynx;
  • HPV mediated oropharyngeal cancer;
  • HPV negative oropharynx;
  • Hypopharynx;
  • Larynx;
  • Major Salivary glands;
  • Nasal cavity and Paranasal sinuses
  • Unknown Primary tumours of the Head and Neck
  • Cutaneous Carcinoma of the Head and Neck*
  • Thyroid cancer –Thyroid cancers in Ireland are often managed by Head and Neck surgeons, and their respective MDTs, whilst a large number of patients are also managed by General surgeons.
  • Others- Sarcomas of the Head and Neck are usually managed in conjunction with the Sarcoma MDT, whilst a large number of lymphomas are diagnosed by Head and Neck Surgeons, and subsequently managed by Haematologist or Medical Oncologist.

* Cutaneous Carcinoma of the Head and Neck are extremely numerous and may be managed by a large number of physicians, from GPs, Dermatologists, General surgeons and the Head and Neck Surgeons listed above. In the main the smaller tumours are managed by simple excision. Larger malignancies that require, for example, neck dissection, parotidectomy, lateral temporal bone resection, rhinectomy, or complex reconstruction, and or adjuvant radiotherapy would often be discussed and managed by Head and Neck surgeons.


It is difficult to precisely estimate the number of Head and Neck Cancer diagnosed per year for a number of reasons. The complexity and diversity of tumours is a challenge from a data management point of view. It is also very difficult to put a number on the patients with cutaneous malignancies managed by Head and Neck MDTs. By examining data collected by the National Cancer Registry Ireland (NCRI), it can be estimated that approximately 940 patients were diagnosed with Cancers of the Mouth and Pharynx (C00-14), Larynx (C32) and Thyroid (C73) Nasal Cavity (C31) and Sinuses (C32) in 2017. As yet unpublished data suggests that this number will be over 1100 patients in 2019. This data suggested the number of Head and Neck Malignancies has increased 300% since 2001

This may be a slight overestimation patients managed by Head and Neck MDTs due to the inclusion of all Thyroid cancers, but it also does not include Sarcoma of the Head and Neck and other miscellaneous malignancies. However in reality it is likely an underestimation as from audit data from the St. James’s Head and Neck MDT suggests that 10% of the workload can be attributed to Cutaneous Malignancy. Therefore a number close to 1200 patients a year may be more accurate.

The increase in incidence is being driven in the main by an increased incidence of Thyroid cancer and HPV positive oropharyngeal cancer, with specific explanations for each which I will discuss later. Unfortunately we are also seeing a slight rise in number of tobacco driven Laryngeal cancer.

Upper Aerodigestive Tract cancers

The majority of the patients we treat are diagnosed with squamous cell carcinoma (SCC) of the upper aerodigestive tract. These patients are frequently men (~75%), and on average approximately 65 years of age. The major risk factors for SCC of the Head and Neck remain smoking and alcohol intake. Smoking increases a patients risk 5 fold, whilst excessive alcohol 3 fold. There is however a multiplier effect, with 15 times the risk seen in smokers who also drink heavily. Betel nut chewing is a major risk factor for oral cancers in India, where it is amongst the most common cancers diagnosed.

Signs and Symptoms

There are a number of “red flag” signs and symptoms that are recognised and warrant a referral to a Head and Neck cancer clinic. In general such a referral should be considered when the symptoms persists for more than 3 weeks, these include

  • Persistent unexplained hoarseness
  • An unexplained lump in the neck, of recent onset or a one changed over a period of 3 – 6 weeks.
  • Unexplained ulceration of the oral cavity or mass
  • Unexplained progressive dysphagia to solids, with/ without weight loss
  • An unexplained persistent swelling in the parotid or submandibular gland
  • An unexplained persistent sore throat especially in those with risk factors
  • Referred otalgia with normal examination/tympanogram, with any of the above symptoms
  • Unexplained persistent unilateral serous otitis media/ effusion in an adult
  • Unexplained new or rapidly enlarging Thyroid lump
  • Large or rapidly progressive skin lesion of the Head and Neck

A rapid access clinic has been established in the Royal Victoria Eye and Ear for such patients, with the view that the patients would be seen within two weeks.

Patients are usually seen in clinic, are examined, which usually includes a flexible nasopharyngeal laryngoscopy, and if appropriate a biopsy or FNA under local anaesthetic may be performed. Patients often require an EUA, or panendoscopy to establish a biopsy proven diagnosis of malignancy. Investigations often include CT, MRI and PET-CT in those with advanced malignancies. Patients are then discussed at MDT, where a management strategy is formulated. Radiotherapy and surgery are the mainstay of treatments for SCC of the Head and Neck. Chemotherapy is often used concurrently with radiotherapy, and in the non-curative setting. Up to 10% of our patients will have distant metastases of extremely advanced locally disease at their presentation.


The choice of radiotherapy or surgery depends on multiple factors, but some generalisations can be made. Tumours in the oral cavity are primarily treated with surgical excision, often with a neck dissection. Early vocal cord tumour can be excised by Laser, whilst patients presenting with T4 or recurrent disease in the larynx will require a laryngectomy. Curative radiotherapy, frequently combined with chemotherapy, can be employed with organ preservation as a goal or to decrease the morbidity associated with surgical excision, when survival outcomes are similar or superior to surgery. This included many laryngeal tumours, nasopharyngeal, hypopharyngeal and oropharyngeal tumours.

Radiotherapy is also often given in the adjuvant setting, post-surgical resection. Radiotherapy is usually given over a period of 6-7 weeks, and in general is well tolerated. Adverse effects such a dry mouth are common, but more severe side effects necessitating NG or PEG feeding is sometimes required. When radiotherapy is utilized in the curative setting, a PET-CT is undertaken 3-4 months after the end of treatment, to ensure a complete response. Salvage surgery may be required if there is residual disease.

The patients that undergo major surgical resections, and thus account for the majority of patients in hospital, fall into two broad categories- those undergoing an oral cavity or oropharyngeal resection often with a free flap reconstruction, or those undergoing a laryngectomy or pharyngolaryngectomy.

Patients undergoing either of these procedures will require extensive preoperative management and post-operative rehabilitation. A large number of allied health professionals are therefore crucial to the patients care. These include Speech and Language therapist, Dieticians, Physiotherapists, and social workers. Patients are also seen by restorative dentists, before both surgery and radiotherapy, and often in the post-operative setting. Clinical nurse specialist are also essential in the management of such patients, guiding them through what can be a daunting journey, and co-ordinating their complex care. A tracheostomy may be required temporarily, and therefore specialist nurses are invaluable in managing such patients. Patients can be admitted for a number of weeks, often including an ICU stay postoperatively. The rehabilitation of swallow and speech can be challenging depending on the extent of surgical excision, but even those post laryngectomy can re-establish intelligible speech.

Recent advances in the field include preoperative digital planning of resections requiring bony reconstruction. This allows the ablative and reconstructive surgeon to plan the surgery in advance, and exact guides to be made that allow both teams to operate concurrently. This shortens operative time, and has been shown to improve outcomes for the patients. Robotic surgery, specifically trans oral robotic surgery (TORS), allowed larger tumours in the oropharynx to be excised per-orum eliminating the need for lip split and mandibulotomy associated with traditional surgery. Studies show some promise, but again, it appears that the proven treatment modality of Radiotherapy is safer, and remains the standard of care. TORS is sure to find a place in our armamentarium, but it is unclear yet as to what that will be.

HPV mediated Oropharyngeal Cancer

The oropharynx is part of the throat at the back of the mouth.

It includes the tonsils, the soft palate, the posterior pharyngeal wall and the back or base of tongue ( this is part of the tongue that can’t be easily seen, and is much more like the tonsils than the muscular front or anterior two thirds of the tongue).

Traditionally, like most Head and Neck Cancers, the major risk factor for oropharyngeal cancer were cigarette smoking, excess alcohol consumption, advanced age and male gender. Although a link between Head and Neck Cancer and Human Papilloma Virus (HPV) has been known since the 1980s, it was only when rapidly increasing incidences in OPSCC were noted in patients without traditional risk factors in the 2000s, that HPV as a causative agent for OPSCC was more widely researched. A landmark paper by Ang et al. in 2010 demonstrated that HPV positive OPSCC who were nonsmokers had a vastly superior (93.5%) 3 year survival, compared to HPV negative OPSCC smokers (41.6% 3 year survival). Further studies corroborated these finding and a distinct carcinogenic pathway was identified.

This has cumulated in HPV mediated OPSCC being recognised as a separate entity in the 8th AJCC staging manual published in 2018.

An audit of Irish cancer centres from 2014-2018 demonstrated that 46% of OPSCC were HPV+ve. This is inline with many developed countries, although some studies have shown a much higher percentage. Audit data from St. James’s Hospital in 2020 revealed that 41 of 55 OPSCC patients (74.5%) were HPV positive.

Patients with oropharyngeal cancer typically present with unilateral symptoms, of persistent sore throat, for more than three weeks, with referred otalgia. A unilateral enlarged or ulcerated tonsil can often be seen. Patients with HPV+ve OPSCC often present with large cystic neck nodes, and relatively small primary tumours. In older staging systems, a patient with this clinical picture, for example T2N2bM0, would be classified as Stage IVa, and HPVve OPSCC would still be staged this way. However with the new AJCC staging, a patient with the same clinical picture, and HPV+ve, would be T2N1M0, and classified as Stage I.

Unfortunately, this has not meant that there has been a change in our standard of care in the management of HPV+ve OPSCC, which is generally either radiotherapy alone, or most often concomitant chemotherapy and radiotherapy. Although a number of studies have been carried out to examine the safety in deescalating these treatments, either through decreasing the dose of radiotherapy or substituting chemotherapy for a less toxic immunotherapy, these studies have thus far failed to demonstrate improved outcomes. Therefore, although HPV+ve patients may have a lower overall stage than their HPV-ve counterparts, they will, at present, receive the same treatment paradigms.

Thyroid Cancer

The incidence of thyroid cancer has increase 5 fold over the past 25 years in Ireland. This spectacular increase however is not an isolated finding, and pales in comparison to South Korea, where a 15 fold increase in incidence was seen and Thyroid cancer is now the most common cancer in women in the country, almost double the incidence of Breast cancer. These phenomena can be explained in the main by over-diagnosis. In South Korea a screening program was established, where a thyroid ultrasound was offered to patients. This led to a large number of nodule being discovered, investigated and thyroidectomies being performed. This led to the massive increase in number of Thyroid cancers.

This can be explained by a number of autopsy studies which demonstrated that up to a third of patients, with no prior history of thyroid disease, had a malignancy at post mortem. The authors of one study suggested that this may be as high as 100%, had the thyroids been dissected to extremely sizes. This implies that we may all have tiny thyroid cancers, that are subclinical and in the vast majority of times will likely remain so. This is supported by a number of studies that have successfully observed small biopsy proven thyroid cancers, with Ito in Japan accumulating over 1000 patients with up to 1cm tumours. Memorial Sloan Kettering in New York offer an active surveillance program for biopsy proved papillary thyroid cancers up to 1.5cms.

In Ireland, no screening program was established, but we have still seen a large increase in incidence, for similar reasons.

Thyroid nodules are often seen incidentally on imaging for other indications, such as MRI spines and CT chests. These are then investigated and for the same reasons as above, malignancies may be diagnosed. It can be challenging to establish whether a thyroid nodule is benign or malignant. Nodules are classified as 1-5 ( U or TiRads classification) on ultrasound to give an indication as to their likelihood of malignancy. An FNA will also give a 1-5 result (Thy system), with a Thy5 denoting malignancy. These investigations therefore need to be carefully considered, as it can be difficult to allay the fears of a patient with a thyroid nodule.

The vast majority of Thyroid cancers are well-differentiated malignancies, with the vast majority of these being papillary thyroid cancers, but also include follicular and hurtle cell cancers. In patients under 55 years of age, and with tumours less than 4cm in size, a thyroid lobectomy will be both diagnostic and curative in the main. Larger tumours, in older patients, or with adverse histological features may require total or completion thyroidectomy and adjuvant radioactive iodine.

Medullary thyroid cancer is a challenging and thankfully uncommon malignancy, that can be familial in origin and is associated with MEN2a and MEN2b. Children with these syndromes require a thyroidectomy at a very young age, to prevent the development of medullary thyroid cancer. Finally Anaplastic thyroid cancer is one of the most aggressive solid organ malignancies in humans, with a median survival measured in just a number of months. Patients usually present with inoperable tumours, but fortunately as few as 10 patients a years are diagnosed with these tumours in Ireland.

Date for your Diary:
The inaugural conference of the multi-disciplinary Irish Head and Neck Society (IHNS) is due to take place on Friday and Saturday, 6-7 May, 2022, at the Kilkenny Convention Centre, Lyrath Estate, Kilkenny, Ireland

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