Heads up: A Pain In The Neck

Heads up: A Pain In The Neck - What are cancers of the head and neck? You might imagine that there is a lot going on in that area, and you would be right.

Consultant clinical oncologist Dr John Low explains head and neck cancers as cancers that occur anywhere from the neck up.

“The cancers are categorised according to the areas of the head and neck from which the cancer cells arise.

“Treatment is challenging due to the complex anatomy and the vital physiological functions of this region.” he says.

The anatomical regions generally referred to are:

Oral cavity: This includes the lips, tongue, gums, the lining inside the cheeks and lips, the floor of the mouth (under the tongue) and the bony top of the mouth (the hard palate).

Pharynx: This is essentially the throat, which can be described as a hollow tube about 13cm long that starts behind the nose and leads to the oesophagus.

The pharynx is further divided into three parts:

• Nasopharynx – the upper part of the pharynx, behind the nose.

• Oropharynx – the middle part of the pharynx, including the soft palate, the base of the tongue and the tonsils.

• Hypopharynx – the lower part of the pharynx.

Larynx: Also called the voicebox, this is a short cartilaginous passageway below the pharynx in the neck. This is where the vocal cords are.

The epiglottis also lies in the larynx. It covers the larynx in order to prevent food from entering the air passages.

Nasal cavity and paranasal sinuses: The nasal cavity is essentially the nose, while the paranasal sinuses (of which there are four pairs) are small hollow spaces in the bones of the head surrounding the nose.

Salivary glands: There are four pairs of the major salivary glands: parotid, submandibular, sublingual and buccal, plus numerous other small glands.

Thyroid gland: This is a butterfly-shaped gland that lies in front of the windpipe, just below the larynx in the neck, and secretes hormones regulating growth and metabolism.

Risk factors

Whilst head and neck cancers are not as common as breast and lung cancers, nasopharyngeal cancer is of particular interest amongst these type of cancers.

“This is a cancer that’s endemic in the Chinese population. It is prevalent in Malaysia, Singapore, China and Vietnam. It is far less common in the West.

“It could be related to the unique dietary habits, specifically the preserved foods like salt-cured fish and meat.

“There is possibly some genetic link as studies have shown that when the same ethnic population migrates to the West, their risk for this cancer doesn’t decrease despite the absence of the same external risk factors,” says Dr Low.

The other recognised risk factors for head and neck cancers are:

• Alcohol and tobacco use – Their role as causal factors cannot be overstated. A 1988 study in the journal Cancer Research found that at least 75% of head and neck cancers are caused by tobacco and alcohol use.

• Infection with certain strains of human papillomavirus (HPV) is a risk factor for some types of head and neck cancers, particularly oropharyngeal cancers.

• Poor oral health and the habit of chewing betel quid have been suggested as causes of cancers of the oral cavity.

• Occupational exposure to wood dust, asbestos and synthetic fibres have been associated with nasopharyngeal cancer and cancer of the larynx.

• It has been observed that prior infection with the Epstein-Barr virus is a risk factor for nasopharyngeal cancer and cancer of the salivary glands.

• Genetic disposition, given that a person of Chinese ethnicity has a higher chance for nasopharyngeal cancer.

Signs and symptoms

Early symptoms of head and neck cancers can be vague and non-specific, and are often mistaken for symptoms of common ailments such as cold and flu.

“Many patients often dismiss these symptoms, and unfortunately, they progress to something more sinister,” says Dr Low.

Early symptoms include:

• A lump or a sore in any area of the head and neck that does not resolve.

• Difficulty or pain in swallowing.

• A change or hoarseness in the voice.

• An ulcer on the gums, tongue or lining of the mouth that fails to heal or any unusual pain or bleeding in the mouth.

• Chronic ringing or pain in the ears, or hearing impairment.

• Chronic sinus infections that do not respond to treatment with antibiotics or frequently blocked sinuses.

• Frequent nose bleeds.

• Pain in the eyes or visual impairment.

Following the initial consultation and thorough examination, further tests like nasolaryngoscopy, CT scans and other imaging studies might be required.

And depending on the findings, a tissue biopsy is usually needed to confirm the diagnosis.

Managing head and neck cancers is a complex and difficult task, given the site of the tumour.

It involves a multidisciplinary team of doctors from various specialties working together with rehabilitation units, speech therapists, dieticians and physiotherapists.

Managing head and neck cancers

The treatment plan for a patient depends on the type, location and the stage of the cancer.

In general, treatment for head and neck cancer, can include a combination of surgery, radiation therapy and chemotherapy.

According to Dr Low, treatment of head and neck cancers have progressed tremendously, especially with regards to radiotherapy.

“We can now fine-tune radiotherapy and deliver it precisely with tumour tracking and image guidance.

“This is called Intensity-Modulated Radiation Therapy (IMRT) and Image-Guided Radiation Therapy (IGRT).

“The radiation beams can be modulated to conform precisely to the shape, size and location of the cancer, hence maximally avoiding collateral damage to the surrounding healthy vital tissues or organs.

“We can adjust the dose of radiation in each of these beams.

“In addition, especially for patients with recurrent head and neck cancer, we can give Intraoperative Radiation Therapy (IORT).

“This involves delivering a concentrated dose of radiation to the tumour bed during surgery in a single treatment session. In this way, we can help reduce side effects and the need to return for repeated radiation treatments.”

Another advancement in the treatment of cancer is immunotherapy.

Recent studies have confirmed the effectiveness of a new class of medicine called checkpoint inhibitors. These have been proven to be effective in heavily pretreated patients with recurrent disease.

Checkpoint inhibitors remove the inhibitory signals from the cancers that evade our immune system. Once the inhibitory signals are removed, our immune system will be activated to attack the cancer from within.

It has long been known that radiation therapy can evoke the ascopal effect – a phenomenon where radiation treatment to the primary cancer can effect the shrinkage and disappearance of the metastatic cancer cells elsewhere in the body.

The likely cause of this phenomenon is the activation of the immune system after radiotherapy.

Radiation therapy from without, and the immune system from within, can work together to fight the cancer. This synergistic effect of radiotherapy and immunotherapy is very promising.

Dr Low advises that both patient and doctor should discuss and consider the recommended standard treatment options available.

“We are treating not just the cancer itself, but the patient as a whole in his own unique context.

“We have to consider the possible consequences and side effects of the various therapies, some of which may be permanent.” he says.

This is particularly pertinent in head and neck cancers. Surgery may sometimes be overwhelmingly disfiguring, and thereafter, challenges the patient’s confidence and identity.

It may also potentially leave the patient with permanent difficulty in chewing, swallowing, speech, and other vital head and neck functions, that would undermine the patient’s quality of life.

Patients who have received radiation therapy to the head and neck region may develop sores in the mouth with painful swallowing, changes in taste and a dry mouth. These side effects can be severely debilitating.

Dr Low concludes: “Though early symptoms can be non-specific and vague, always be vigilant and mindful.

“Head and neck cancers are highly curable, especially with early detection. Prompt diagnosis and timely treatment offer us an advantage in doing the best that we can for our patients.