Head and neck cancer covers a large group of cancers that arise in this region of the body. They have a similar appearance down the microscope (they are virtually all squamous carcinomas) and have many similarities in their mode of behaviour and spread. The commonest site of origin is the larynx, followed by the oral cavity (the mouth)
Although the incidence is falling in the UK, the incidence is still high world wide and the environmental factors that predispose are the main reason for this large geographical variation in incidence.
The most important risk factor is smoking, which dramatically increases the risk of head and neck cancer. If smoking is combined with alcohol, the risk increases further.
Various other environmental factors that have been associated with a higher incidence of head and neck cancer are exposure to chromium and nickel dusts and various leather workers and wood workers have rarely been found to have a higher incidence of cancers of the nose or nasal sinuses.
Nasopharynx cancer, which is a slightly unusual subtype of the squamous carcinomas of this region, is related in its incidence to exposure to salty fish in the diet and Epstein-Barr virus infection. It is more common in the Far East.
Squamous head and neck cancer is more common in males.
More recently, cancers of the oropharynx (the tonsil, back of the tongue, and the palate) have been linked to Human Papilloma Virus infection.
Chewing Paan or Beetle Nut, increases the risk of cancer of the tongue, inner cheek and the gums.
The title head and neck cancer refers to a large group of cancers that arise in this region of the body, have a similar appearance down the microscope (they are all squamous carcinomas) and have many similarities in their behaviour and spread.
The commonest site of origin is the larynx, followed by the oral cavity (the mouth) and this is followed by the throat (pharynx – divided in to the postnasal space or nasopharynx, the oropharynx and the lowest region, called the hypopharynx, which inferiorly leads into the oesophagus). Carcinoma of the lip is the least common type.
In the UK, there were about 7500 cases of head and neck cancer in 2004.
Symptoms & diagnosis: Head and neck cancer
The symptoms of cancers of the head and neck depend on where they arise.
- A lump in the neck that does not go down after antibiotics
- A lump in the mouth or back of the throat
- An ulcer in the mouth that does not heal
- A loose tooth
- A tooth socket that does not heal after the tooth has been removed
- Dentures that do not fit properly when they used to fit well.
- Pain on swallowing that does not get better
- Pain in the ear that does not get better
- Repeated nose bleeds
- A chronically blocked nose
- Double vision
- Severe headaches
- Swelling of the cheek
- Swelling of the front of the face
- A change in the quality of the voice
The difficulty is that many of the above symptoms can be caused by problems totally unrelated to cancer. Suspicion is raised if things do not improve.
Tests that are run to define the diagnosis include an endoscopy, when a thin flexible camera is put into the upper part of the throat, via the nose. This allows the doctor to look directly at the inside of the head and neck.
Blood tests and scans of the head and neck are often done. The scans may be all or any of a CT scan, an MRI Scan or and Ultrasound of the neck. The scans help to check where the tumour is and if it has spread.
The diagnosis of head and neck cancer can only be confirmed if, a sample of the lump is removed and then examined under the microscope to look at the cells very closely.
The ‘stage’ of the cancer defines whether the tumour is localised to the organ, whether it has invaded nearby structures, whether it has spread to the local lymph nodes or whether it has spread to other parts of the body. The treating oncologist needs to know the stage to decide the most suitable treatment.
The information needed to decide the stage is gathered from both clinical examination and scanning. An examination under anaesthetic is often done to obtain the most accurate stage, and to get a biopsy.
The stage is usually classified using a system called the ‘TNM Staging System’, where T stands for tumour, N for ‘nodes’ (ie lymph nodes), and M for ‘metastases’ (ie whether other organs are involved). Each letter is followed by a number that defines the extent of the cancer eg T2N1M0.
The diagnosis is confirmed by taking a sample of the lump or suspicious region, and having this examined under a microscope by a specialist. The biopsy may be taken in the out patient clinic, but usually a full examination of the area is undertaken whilst the patient is under anaesthetic. This allows a much more thorough examination to be done. The biopsy can be taken during this procedure. Other tests that are done include a CT scan and an MRI scan.
Treatment & outcomes: Head and neck cancer
The treatment of head and neck cancer depends on where it is and if or where it has spread to. If the tumour has not spread to other parts of the body it may be possible to cure.
The available treatments for cure are surgery, radiotherapy and chemotherapy. The treatment chosen has to have, a good chance of working, whilst having as little effect on the quality of life after treatment. This is often a difficult balance because some of the surgery needed to cure the tumour may remove an important part for example the voice box or part of the tongue. This has effects on speech and swallowing. The advantage of radiotherapy is that it can destroy the tumour whilst leaving the organ in place so patients are, for example, still able to speak and swallow. However, if the tumour is too large or invades bone or cartilage, radiotherapy does not work so well and surgery may be the only chance of cure.
In general, therefore, if the tumour can be removed by an operation without affecting the patient too much, then an operation is recommended. If the operation will significantly affect the patient’s function, then radiotherapy is recommended. If, however the tumour is advanced, then an operation is the only choice and the after effects are accepted but minimised as much as possible.
Radiotherapy can be given after surgery to minimise the chances of the tumour returning.
It is now known that radiotherapy is more effective if chemotherapy is given at the same time. This adds to the side effects and is not suitable for all patients but usually improves the results of treatment.
Recent research also suggests that the effect of radiotherapy can be improved if a drug called Cetuximab is given at the same time as the radiotherapy. It is given intravenously weekly during the treatment, with the first treatment being given the week before the radiotherapy starts. Currently, it is generally used if Chemotherapy cannot be given safely.
Radiotherapy of the head and neck has a lot of side effects, most of which subside completely 2 to 3 months after the end of the radiotherapy. Some effects may be permanent. One of these is a dry mouth, which occurs if the salivary glands receive a high dose of treatment. However, some specialist centres are able to use a type of radiotherapy called ‘intensity modulated radiotherapy’ (IMRT) which can keep the dose to normal tissues low whist still treating the tumour to a high dose. This can avoid the problem of a permanent dry mouth for a lot of patients. IMRT may also allow a technically better treatment of the tumour than standard radiotherapy methods.
The treatment of head and neck cancer should be done in specialist centres. This is because the surgery is often complex and requires not only skilled surgeons but also well organised aftercare and rehabilitation. The radiotherapy treatment is also complex and, when combined with chemotherapy, is a tough treatment for patients and so needs specialist expertise.
What happens if the treatment is not successful?
If the cancer relapses after radical radiotherapy, salvage surgery is often an option.
If there is a relapses in the neck nodes, but the main tumour is controlled, then cure is possible by an operation on the neck. If the tumour returns after an operation and radiotherapy has not been given, then it may be possible to aim for cure with radiotherapy.
If the tumour has spread to other parts of the body, then the aim of treatment is to maintain and maximise the quality of life. This may involve chemotherapy, given intravenously.
Screening for head and neck cancer is not routinely performed as the disease is, overall, rare.