What is Oral and Oropharyngeal Cancer?

According to Cancer Research UK, 1 in 55 men and 1 in 108 women will be diagnosed with oral cancer at some point in their life. Each year, there are about 8,500 new cases of oral and oropharyngeal cancer in the UK. About 70% of these cancers are linked to Human Papilloma Virus (HPV), a common virus that, for most people, causes no harm. Some cases of oral and oropharyngeal cancer could be prevented.

What is oral and oropharyngeal cancer?

Oral and oropharyngeal cancer is cancer that is within the mouth and/or the oropharynx. The oropharynx is the part of the throat that is just behind the mouth. It includes cancers that are found in the tonsils and at the back of the tongue. Sometimes oral cancer is called mouth cancer and oropharyngeal cancer is described as a type of throat cancer.

The medical term for your mouth is the ‘oral cavity’, and so mouth cancer can start anywhere in the mouth including:

• Gums (gingiva).
• Lips.
• The buccal mucosa (the inside lining of the lips and cheeks).
• Front two-thirds of the tongue.
• The hard palate (roof of the mouth).
• The floor of the mouth.
• The retromolar trigone (the area behind your wisdom teeth).

The medical term for your throat is the pharynx.

It is divided into three distinct parts:

• Oropharynx.
• Nasopharynx.
• Laryngopharynx.

Oropharyngeal cancers start in the oropharynx.

This area includes:

• The back one-third of the tongue.
• The soft palate (the soft area towards the back of the mouth).
• The tonsils and the tonsillar pillars (the two ridges in front and behind the tonsils).
• The back wall of the throat.

Oral and oropharyngeal cancers are often grouped together because they can begin in the same types of cells. Also, there are similar tests and treatments for both kinds of cancer which is another reason they are often grouped. Throat cancers are not just oropharyngeal cancers, and this is why it is better to be specific when referring to a type of cancer.

What are the signs and symptoms of oral and oropharyngeal cancer?

The signs and symptoms of oral and oropharyngeal cancer include:

• Pain in the mouth.
• Ulcers that won’t heal.
• Swelling in the mouth or throat.
• White or red patches in the throat or mouth.
• Speech difficulties.
• Difficulties swallowing.
• A lump felt in the neck or under the chin.
• Bad breath.
• Weight loss.

The symptoms above are also fairly common symptoms for other conditions that are not related to cancer. If you have one or more of the symptoms above, you are far more likely to have another condition rather than oral and/or oropharyngeal cancer. However, people should see their doctor if they have ulcers that won’t heal, discomfort or pain that won’t go away, or any unusual or persistent symptoms.

The most common symptoms from the list that people with oral and oropharyngeal cancer complain of are ulcers that won’t heal and pain or discomfort that does not go away.

White or red patches

White or red patches in the mouth or throat are not always a sign of cancer. In most cases, they are not anything to worry about. Most often, they are a sign of oral thrush which is a common fungal infection.

However, abnormal-looking patches can be a sign of pre-cancerous or cancerous changes. Red patches in the mouth are called erythroplakia and white patches are called leukoplakia. Although they are not cancer themselves, they could turn into cancer if they are left untreated.

Speech difficulties

Oral and oropharyngeal cancer can affect the voice. A person’s voice may sound husky, quieter, more nasal or just different in some other way. Some people may find that they slur their words or have difficulties pronouncing certain sounds.

Difficulty swallowing

Oral cancer can cause a burning sensation or pain when someone is chewing and swallowing food. Other people report that it feels like food is getting stuck in their throat. This can also be caused by a narrowing of the oesophagus (the food pipe).

A lump in the neck or under the chin

Lumps in the neck are usually caused by enlarged lymph nodes. Enlarged lymph nodes are not often a sign of cancer. Indeed, if you are run down or have the flu, for example, you may find that your lymph nodes are enlarged as they are fighting off infection. However, persistently enlarged lymph nodes in your neck can be a sign of oral and oropharyngeal cancer. Lumps caused by cancer typically do not go away and continue to grow.

Lumps that disappear, even if they return and disappear again, are unlikely to be cancer and are more likely a reactive lymph node. Hot, painful and red lumps are typically signs of infection rather than a type of cancer.

Bad breath

Bad breath is quite a common ailment and shouldn’t be something that most people are worried about. However, if someone does have oral and/or oropharyngeal cancer, they may suffer from worse bad breath more regularly.

Weight loss

Weight loss is a common side effect of many types of cancer. Oral and oropharyngeal cancers often make it difficult for someone to eat and swallow food which may mean that they lose weight. Extreme unexpected weight loss (i.e., if you are not dieting) is a sign that someone’s cancer is advanced.

Other signs of oral and oropharyngeal cancer

There are other signs and symptoms of this type of cancer too.

These include:

• Lumps in the throat or mouth.
• A thickening or lump on the lip.
• Unusual numbness in the mouth.
• Unusual bleeding from the mouth.
• Wobbly teeth with no obvious cause.
• A stiff jaw.
• A persistent sore throat.
• Persistent ear pain.

What causes oral and oropharyngeal cancer?

In some cases, it is unclear what has caused oral and oropharyngeal cancer to develop. These types of cancer can start in different parts of the mouth and oropharynx when abnormal cells begin to grow and multiply uncontrollably.

According to the NHS, the leading causes of oral cancer in the UK are tobacco and alcohol. Both tobacco products and alcohol are known carcinogens, which means that they contain chemicals that damage the DNA within cells. This damaged DNA is what can cause cancer to develop as the abnormal cells multiply rapidly and become out of control.

Scientists still do not know the exact trigger for the DNA changes that result in oropharyngeal cancers, or why not everyone who smokes or drinks alcohol goes on to develop it. However, it is clear that both smoking and drinking alcohol are clear risk factors for developing oral and oropharyngeal cancers. Let’s take a look at the risk factors in more detail.

What are the risk factors of oral and oropharyngeal cancer?

We have mentioned that smoking and drinking alcohol increases a person’s risk of developing oral and oropharyngeal cancer. However, there are other risk factors for the disease too.

These include:

• Smokeless tobacco use such as chewing tobacco or snuff.
• Betel nuts.
• Poor diet.
• Human Papilloma Virus (HPV).
• Poor immune system.
• Family history.
• Mouth conditions and oral hygiene.
• Previous cancers.
• Sunbeds and sunlight exposure.
• Lack of physical activity.
• Certain blood pressure drugs.

Smokeless tobacco

Many people wrongly believe that smokeless tobacco is safer to use than smoking it. However, this is not correct. Smokeless tobacco includes things like chewing tobacco and snuff – tobacco in a powdered form that is snorted.

Betel nuts

Betel nuts are the seeds from the betel palm tree and they are mildly addictive. Many communities in South Asia use betel nuts including those from India, Pakistan, Bangladesh and Sri Lanka.

Betel nuts work in a similar way to coffee in that they are a slightly addictive stimulant. However, they are carcinogenic and increase the risk of mouth cancer. Many people in South Asia or those of South Asian origin also chew betel nuts with added tobacco. This increases the risks further. This tradition means that the rates of mouth cancer in these ethnic groups are often higher than in other ethnic groups or in the British population as a whole.

Poor diet

Most people are aware that a good diet is the main way of keeping in optimum health. A poor diet increases a person’s risk of developing many cancers, and that includes oral and oropharyngeal cancers too. Diets that are low in fruit and vegetables are thought to contribute to the incidence of these cancers as a lack of vitamins and minerals is a contributory factor.

Human Papilloma Virus

HPV is a virus that infects cells in the linings of our body cavities as well as the skin. It is thought that about 80% of people will have caught the virus at some point in their lifetime. For the majority of these people, the virus does not cause any harm and it resolves by itself. However, this virus can cause changes in the cells in the mouth and throat. It is these changes that can later develop into cancer in the future.

HPV spreads through skin-to-skin contact, usually during sex. There are many kinds of HPV and each one has a number. The number of the type of HPV that causes most oral and oropharyngeal cancers is HPV 16. Around 25% of oral and oropharyngeal cancers are thought to have been caused by HPV. This link is much stronger for cancers originating in the oropharynx than in the mouth.

Those who have HPV-positive oral and oropharyngeal cancers tend to be younger and do not usually smoke or drink alcohol, only rarely. That being said, HPV-positive oropharyngeal cancers tend to have a more positive outlook than those that are HPV-negative.

Poor immune system

The body’s immune system is what fights infection in the body. For someone with a poor or weakened immune system, their chance of getting cancer increases.

There are many reasons why someone’s immune system may be weakened. It can be due to illness or medications that control illnesses such as immunosuppressant medications. This includes those with HIV/AIDs (these people also have higher rates of HPV infection) and those who take immunosuppressants after having had an organ transplant.

Family history

According to Cancer Research UK, there is a slight increase in a person’s risk of developing oral and oropharyngeal cancer if a very close relative such as a sibling or parent has had head or neck cancer. No one really knows why this is and further research is needed.

Mouth conditions and oral hygiene

The cells that line the mouth such as in the buccal mucosa, for example, can undergo changes. These can develop into white or red patches and, in some cases, these can go on to develop into cancer over a period of several years. These conditions are often labelled as being ‘pre-cancerous’.

As for oral hygiene, cancer can be linked to persistent wounds and so there is a very small chance that a person’s oral hygiene can contribute to their risk of developing oral and oropharyngeal cancer. For example, if a jagged tooth causes a persistent sore in a person’s mouth, this can increase the risk of the sore or ulcer turning into cancer further down the line. This is why practising good oral hygiene is considered to be an essential part of everyone’s daily routine.

Previous cancer

For those who have had a previous cancer either in their mouth or elsewhere in their head and neck, unfortunately, this means that they are at an increased risk of developing a second cancer in the same area.

The risk of developing oral and oropharyngeal cancers is also increased for those who have had other types of cancers including:

• Squamous cell cancer of the cervix.
• Oesophageal squamous cell cancer.
• Lung cancer.

Sunbeds and sunlight exposure

Most people are aware that too much ultraviolet (UV) radiation from sunbeds or from the sun itself increases a person’s risk of developing skin cancer. Skin cancers of the head and neck are common because these areas are exposed most often to the sun’s rays. This means that skin cancer can develop on the lip and is therefore considered a type of oral cancer.

Lack of physical activity

Of course, a lack of physical activity does not mean that a person is guaranteed to develop cancer of any kind. However, being inactive generally does increase a person’s risk, and research suggests that those who are not very physically active are much more likely to go on to develop oral and oropharyngeal cancer. No one knows why this is and more research is needed.

Blood pressure medications

A blood pressure drug called hydrochlorothiazide is known to increase a person’s sensitivity to sunlight. This, in turn, can cause a person to develop skin cancer of the lip (amongst other places).

Can oral and oropharyngeal cancer be prevented?

Preventing oral and oropharyngeal cancer is multifactorial. Essentially, to prevent one’s risk of developing the disease, a person must address the risk factors.

This can be achieved by:

• Not smoking (or stopping).
• Not using other tobacco products or Betel Nuts.
• Practising safe sex to avoid HPV infection.
• Eating a healthy diet with plenty of fruits and vegetables.
• Maintaining good oral hygiene and visiting a dentist regularly.
• Keeping physically active.
• Reducing exposure to harmful UV rays by wearing sunscreen, wearing a hat, staying in the shade and not using sunbeds.
• Being extra vigilant for changes if you’ve previously had cancer, particularly squamous cell cancer of the cervix or oesophagus, or lung cancer.

Of course, not all cases of oral and oropharyngeal cancers can be prevented. However, lowering one’s personal risk of developing the disease is always a good idea. By addressing the risk factors for this kind of cancer, you also reduce your risk of developing other kinds of cancers too (such as lung, bowel, breast and other cancers).

What are the types, stages and grades of oral and oropharyngeal cancer?

There are several types of oral and oropharyngeal cancers. Most (over 90%) start in squamous cells and are therefore called squamous cell carcinoma (SCC).

Other types of oral and oropharyngeal cancers include:

• Adenoid cystic tumours.
• Salivary gland tumours.
• Lymphoma.
• Melanoma.
• Basal cell carcinoma.

There are four stages used to describe oral and oropharyngeal cancers. However, cancers in the mouth are staged differently from oropharyngeal cancers.

Oral cancer staging

Mouth cancer is staged both clinically and pathologically. Clinical staging happens before any surgery takes place and this is used to determine a treatment plan. Clinical staging is sometimes written as cTNM. Pathological staging is what happens after surgery where the results of surgery are analysed in combination with other tests. Pathological staging is sometimes written as pTNM.

• Stage 0 or Carcinoma in Situ (CIS)
  – This means that the oral cancer is at a very early stage, and it is sometimes called ‘pre-cancer’. Cancer cells are present; however, they are all contained within the lining of the mouth and have not spread. If the cancer cells are not treated, then there is a very high risk that they will develop into an invasive cancer.
• Stage 1
  – This is the earliest of the stages of invasive cancer. In practice, it means that the cancer in the mouth is less than 2cm in size and less than 5mm deep. It also has not spread to any tissues, lymph nodes or elsewhere.
• Stage 2
  – Stage 2 oral cancer can mean either the cancer is 2cm or smaller and it is deeper than 5mm but less than 10mm, or it is larger than 2cm but smaller than 4cm, and it is less than 10mm in depth. This stage also means that it has not spread elsewhere.
• Stage 3
  Stage 3 oral cancer can mean any one of the following:
  – The cancer is bigger than 2cm, less than 4cm, and more than 10mm deep, and it hasn’t spread elsewhere.
  – The cancer is larger than 4cm, but no deeper than 10mm, and has not spread elsewhere.
  – The cancer is of any size but a lymph node on the same side also contains cancer cells and is less than 3cm in width.
• Stage 4
  Stage 4 is the most advanced stage of oral cancer. It is subdivided into Stages 4a, 4b and 4c.
  – Stage 4a
  This can mean that the cancer has grown into the surrounding structures and is not just within the mouth. It might also have spread to a lymph node which is smaller than 3cm.
  It can also mean that the cancer isn’t of any particular size but it has spread into at least one lymph node in the neck, on either side. The lymph nodes affected measure between 3cm and 6cm.
  – Stage 4b
  Stage 4b can mean several things. It can mean that the cancer has spread to surrounding areas such as the base of the skull, behind the jaw, or around the carotid arteries. It can mean that a cancer-containing lymph node measures more than 6cm. It can also mean that the cancer has spread to the area surrounding a lymph node.
  – Stage 4c
  Stage 4c oral cancer means that the cancer has spread further and includes other parts of the body such as the bones or lungs.

Oral cancer grades

Oral cancer is also graded. The grade defines how different the cancer cells appear when compared with other cells and also indicates how the cancer may behave and how it will respond to certain treatments.

1. Grade 1 oral cancer

Low Grade. The cancer cells resemble typical mouth cells.

2. Grade 2 oral cancer

Intermediate Grade. The cancer cells look a little different to typical mouth cells.

3. Grade 3 oral cancer

High Grade. The cells look abnormal and do not resemble typical mouth cells.

Oropharyngeal cancer staging

As mentioned, staging oropharyngeal cancer is somewhat different to staging oral cancer. Clinical and pathological staging are still used but the number staging and grading work slightly differently.

• Stage 1
  – Stage 1 oropharyngeal cancer means that the cancer is less than 4cm in size. The lymph nodes on the same side of the neck may also contain some cancer cells but none of the nodes is more than 6cm.
• Stage 2
  Stage 2 oropharyngeal cancer means either:
  – The cancer measures 4cm or less and there are cancer cells in the lymph nodes on the other side of the neck to where the cancer is located or that both sides of the neck’s lymph nodes are affected.
  – The cancer is bigger than 4cm in size, or it has spread into the epiglottis (the flap at the top of the larynx), and the lymph nodes contain cancer (but are less than 6cm in size).
• Stage 3
  Stage 3 oropharyngeal cancer means either:
  – No matter the cancer size, the lymph nodes contain cancer and one or more are bigger than 6cm.
  – The cancer has spread locally into nearby areas such as the jawbone, larynx, or extrinsic muscles that connect the jawbone and the tongue. It may have spread to the lymph nodes too.
• Stage 4
  – Stage 4 oropharyngeal cancer means that the cancer is at its most advanced stage and has spread elsewhere in the body such as the bones or the lungs.

Can oral and oropharyngeal cancer be detected early?

Most oral and oropharyngeal cancers are diagnosed when a person spots changes in their mouth or shows one of the signs or symptoms listed above and has further testing.

There is no typical screening for oral and oropharyngeal cancers. However, early changes may also be spotted by your dentist and, as such, it is important to attend regular dental check-ups. Sometimes, dentists use special dyes to identify problem areas in the mouth and these can highlight changes which can be monitored or tested. However, there is no definitive early detection test for these types of cancers.

How is oral and oropharyngeal cancer diagnosed?

For most people, their first port of call when they experience symptoms of mouth cancer is usually their GP. Also, sometimes changes are picked up by a dentist. The GP will usually examine the inside of the mouth as well as look at the back of your throat. They will then refer you to the hospital to see a specialist.

In England, Wales and Northern Ireland, there are guidelines as to when GPs should refer a patient to the hospital.

These include:

• A neck lump that’s unexplained and persistent.
• Mouth ulcers that do not go away after three weeks.

They also should consider referrals if someone has a lump on their lip or in the mouth that doesn’t go away or red/red and white patches inside the mouth if these are not thought to be due to oral thrush.

In Scotland, the guidelines are slightly different.

GPs or dentists should refer patients to a specialist if they have one of the following:

• A lump in the neck that can’t be explained.
• A swelling or ulceration in the mouth or on the lip.
• Red/red and white patches in the mouth that are not thought to be due to oral thrush.
• A persistently painful or sore throat.
• Unexplained painful swallowing.
• A hoarse voice that is unexplained.

In England, there is a two-week target time for hospitals to see suspected cancer patients. Although the time limit does not exist in other parts of the UK, hospitals always endeavour to see patients who have symptoms of cancer as quickly as possible.

Once a patient is referred to a specialist, they may undergo several tests to determine if their symptoms are oral or oropharyngeal cancer.

These tests include:

• Biopsies.
• Blood tests.
• Lymph node testing.
• CT scan.
• MRI scan.
• X-rays.
• Barium swallow.
• PET-CT scan.

Biopsies

A biopsy is where a sample of the affected tissue is taken and analysed under a microscope. This will give clear results as to whether the tissue contains cancer cells. There are different kinds of biopsies depending on the location of the suspected cancer. You may have a nasendoscopy, a panendoscopy, or an incisional biopsy.

A nasendoscopy looks at the inside of the mouth, the pharynx (the throat) and the larynx (voice box). A panedoscopy looks at the upper airway including the mouth, nose, larynx and top of the oesophagus. An incisional biopsy is where an incision is made and a small amount of tissue is removed if the area is easy to reach such as on the lip, insides of the cheek or the tongue.

Blood tests

Whilst blood tests are not typically diagnostic of oral and oropharyngeal cancers, they can give specialists a general overview of your physical health including how well the kidneys and liver are working.

Lymph node testing

Lymph node testing is done via fine needle aspiration or a needle biopsy. This means that a doctor inserts a needle into the lymph node and takes some of the cells within it to examine under a microscope. These cells will be tested to find out if they contain any cancer cells.

CT scans

A CT scan gives a thorough picture of the head and neck and can see whether there is any cancer present or if the cancer has spread.

MRI scans

An MRI scan gives the doctor a view of the inside of the body from all angles. It can help to find out where any cancer is and if it has spread. Soft tissue shows up very clearly on MRI scans and so any abnormalities can be detected fairly easily.

X-rays

X-rays are sometimes taken to look at the bones in the head and neck to see if there are any changes that could have been caused by cancer. X-rays can sometimes show if cancer has spread to other parts of the body. Sometimes, a special x-ray called an orthopantomogram is taken.

This is sometimes called a panorex scan or OPG. This scan takes pictures of the maxilla (the upper jawbone) and the mandible (the lower jawbone). Cancer around these bones usually shows up on this kind of x-ray.

Barium swallow

A barium swallow is usually used to look at the digestive system. Many people have this if they are having difficulty swallowing food, which can be a symptom of oral or oropharyngeal cancer.

Someone having this test will not be permitted to eat or drink for a few hours before the test. Once in the x-ray room, the patient stands in front of the x-ray machine and drinks a white barium liquid. A series of x-rays are taken as the liquid is swallowed.

PET-CT scan

A PET-CT scan gives doctors very detailed information about cancer. This scan is usually undertaken to show doctors the extent of a person’s oral or oropharyngeal cancer and whether it has spread. The PET scan uses a drug that is mildly radioactive so that it shows up on the scan, highlighting areas where there is more cell activity than normal.

Diagnosis

Most people with oral or oropharyngeal cancer receive their diagnosis after a combination of these tests.

How is oral and oropharyngeal cancer treated?

There are many options for treating oral and oropharyngeal cancer. Many of the options depend on exactly where the cancer is, what stage it is and if it has spread.

Treatments may include:

• Surgery.
• Chemotherapy.
• Radiotherapy.
• Chemoradiotherapy.
• Immunotherapy and targeted cancer medicines.

Surgery

Having surgery is a common treatment for oral and oropharyngeal cancers especially if they are in the early stages. For some people, surgery may be the only treatment they need as the cancer may be able to be removed completely through surgery.

Surgery will depend on the location and size of the cancer. Usually, a surgeon will remove the cancerous area and an area of healthy tissue that surrounds it. Some lymph nodes may also be removed. Some people need bigger surgical operations including removing parts of their jawbones. Quite often this means that they require reconstructive surgery to rebuild their jaw or face.

Chemotherapy

Chemotherapy treatment is where cytotoxic drugs (cancer-fighting medicines) are circulated in the bloodstream. Some people with oral and oropharyngeal cancer first undergo chemotherapy to shrink any tumours or cancerous areas of tissues before they have surgery to remove the rest. Others will have chemotherapy after surgery to ensure that any remaining cancer cells are treated and destroyed.

Radiotherapy

Radiotherapy is where high-energy rays that are a bit like x-rays are used to kill off cancer cells. A machine directs a beam of radiation to the area affected by cancer. Sometimes, radiotherapy is used instead of other treatments or in combination with other treatments.

Brachial radiotherapy is internal radiotherapy. This is often used for mouth cancers that are in the very early stages.

Chemoradiotherapy

This is where radiotherapy and chemotherapy are combined together. This is sometimes used after surgery or instead of surgery if the cancer has already spread into the lymph nodes or to nearby tissues.

Immunotherapy and targeted cancer medicines

Targeted cancer medicines work by finding the differences between normal cells and cancer cells in the parts that help the cells grow, multiply and survive. Some other drugs also help the body’s natural defences in the immune system to attack the cancer cells. Some immunotherapy drugs are Cetuximab (Erbitux) or Nivolumab (Opdivo).

Stages and treatment

The treatment for oral and oropharyngeal cancers is largely dependent on the stage of the cancer.

With Stage 0 cancer (Carcinoma in situ, CIS), the biopsy may have completely removed the cells. However, sometimes minor surgery is carried out to remove the area completely. If cells return, a short course of radiotherapy is usually all that’s required to stop it from coming back.

For cancers at Stages 1 and 2, the treatment will depend on where the cancer is, but normally the treatment is usually surgery (with chemotherapy or radiotherapy after the surgery) or radiotherapy on its own.

For cancers at Stages 3 and 4, the main treatment plans include surgery (with radiotherapy or chemoradiotherapy afterwards), chemoradiotherapy on its own, or palliative care to treat the symptoms only.

Final thoughts on ‘What is Oral and Oropharyngeal Cancer?’

Anyone who receives a cancer diagnosis will be shocked and worried about what their diagnosis means. However, it is important to note that many cancers in this area are very treatable.

Additionally, given that some of these cancers can be prevented or can be detected at a very early stage, it is important to be vigilant for changes as well as lead as healthy a life as possible to reduce the risk of such cancers occurring.