What to do about oral cavity cancer

Key facts in short

• Definition: Oral cavity cancer refers to a malignant tumour in the mouth and throat that can spread via the lymph nodes and bloodstream, thereby leading to metastases in other organs.
• Symptoms: The first signs of oral cavity cancer can be white, red or grey spots that cannot be wiped off, as well as rough or hardened patches. Numbness can also be an indicator of oral cavity cancer.
• Causes: Smoking and drinking alcohol on a regular basis can drastically increase your chances of developing oral cavity cancer. Poor oral hygiene, HPV infections and constant irritation of the oral mucosa can also trigger the growth of cancerous tumours.
• Diagnosis: A doctor examines the oral cavity and throat thoroughly and takes a tissue sample. If your doctor suspects oral cavity cancer, MRI or CT scans will be undertaken and reviewed.
• Treatment: Surgery is normally required to remove the tumour. This can be combined with radiotherapy and/or chemotherapy.
• Prognosis: The earlier oral cavity cancer is spotted, the better the chances of recovery. The average five-year survival rate is 50 per cent.
• Preventative measures: If you do not fancy developing oral cavity cancer, definitely give up smoking and minimise the amount of alcohol you consume. Further, thorough oral hygiene and regular check-ups are also important.

Definition of oral cavity cancer

To define oral cavity cancer, we first need to understand what cancer is exactly. Everyone has heard of cancer and knows that it is a serious and debilitating condition. But what causes cancer is not always clear.

Digression: What is cancer exactly?

Cells in our bodies are constantly being renewed – some faster, some slower. The old cells die and are replaced by younger ones with the same genetic information. That is a completely normal bodily function. Cancer develops when an imbalance occurs and cells with altered genetic information are not recognised and destroyed by the body. These altered cancer cells multiply faster than the non-cancerous ones, thereby gradually displacing the healthy cells. Further, these mutant cells do not die when they should and multiply uncontrollably.

It becomes dangerous when the cancer cells – unrecognised by the immune system – start to spread to other parts of the body through the bloodstream or the lymphatic system and develop as metastases in vital organs, thus impairing their correct function. 

What is oral cavity cancer exactly?

Oral cavity cancer (technical term: oral squamous cell carcinoma) refers to a malignant tumour in the oral cavity and throat. In 95 per cent of cases, the cancer originates in the squamous stratified epithelium, the uppermost layer of the oral mucosa.

Metastases often develop in the lymph nodes. However, metastases can also form in other organs through the bloodstream – for example in the lungs, liver and adrenal glands.

These images show oral squamous cell carcinoma as a photograph and as a scanning electron microscopy (SEM) image. In the latter, you can clearly see that the cancer cells are growing uncontrollably and displacing healthy tissue.

Frequency of oral cavity cancer

Oral squamous cell carcinomas account for around five per cent of all malignant tumours. In Germany, roughly 12,000 people are diagnosed with oral cavity cancer each year. In Switzerland, the number is about 1,200. Moreover, approximately two thirds of those affected are men. Although the number of women developing the disease is increasing. In men, oral squamous cell carcinomas are the seventh most common malignant tumours – in men under 50, oral cavity cancer is second only to testicular cancer.

Those at highest risk are men aged between 55 and 65 and women aged between 50 and 75. However, an increasing number of young people are developing oral cavity cancer – for example in their twenties and thirties. Around ten per cent of those affected are under 50 at the time of their diagnosis. Oral cavity cancer is very rare among children.

Worldwide, roughly 200,000 to 350,000 people are diagnosed with oral cavity cancer every year – with this number set to increase in the future. 

Prognosis: What are the chances of recovery from oral cavity cancer?

The earlier oral cavity cancer is spotted, the better the chances of recovery. In fact, oral cavity cancer can be cured in 80 to 90 per cent of cases if detected early. That said, 70 per cent of oral squamous cell carcinomas are only diagnosed at an advanced stage, which makes treatment more difficult and less effective. Studies show that a relapse often occurs within two years in those who initially responded well to treatment. Once again, the risk of this is much higher if the oral cavity cancer is already in an advanced stage when diagnosed.

Unfortunately, we are unable to make any general predictions regarding the duration and effectiveness of treatments, as they depend on many individual factors.

However, key factors that impact the prognosis are:

• Size of the tumour
• Spread of the disease (especially development of metastases in the lymph nodes)
• Aggressiveness of the tumour

Life expectancy of people with oral cavity cancer

The value typically used to indicate the chances of survival of cancer patients is the average five-year survival rate. This value indicates the proportion of patients who are still alive five years after being diagnosed with the disease. For patients diagnosed with oral cavity cancer, the value is 50 per cent. This also means that 50 per cent of those diagnosed will die of the disease within five years. The other 50 per cent are either cured or live longer than five years despite having oral cavity cancer.

Symptoms: How is oral cavity cancer detected?

Oral cavity cancer occurs in various stages of progression. To recognise the disease as early as possible, you should know the tell-tale signs. 

First signs of oral cavity cancer

These signs might generally indicate the development of oral cavity cancer:

• Patches in your oral cavity: You should definitely keep an eye on white, grey or red spots in the oral cavity that cannot be wiped off. Many people dismiss them as pressure points caused by dentures or bite injuries. If these spots fail to disappear within about 14 days, you should definitely have them checked by your doctor.
• Rough, hard patches in your mouth
• Numbness of the lips, teeth or tongue
• Bad breath
• Bleeding (without the oral mucosa being injured)
• Pain when chewing or swallowing
• Excessive flow of saliva
• Sores that bleed easily but fail to heal
• Swelling in your mouth
• Sensation of a foreign body in your oral cavity
• Numbness that restricts mobility of the tongue
• Difficulty talking
• Dentures that no longer sit properly
• Burning sensation of the oral mucosa
• Loose teeth
• Headache
• Neck pain
• Chronic cough, including coughing up blood
• Enlarged lymph nodes
• Throat pain
• Ear pain

How do you differentiate between oral cavity cancer and aphthae?

In the early stages, aphthae and oral cavity cancer can look very similar. In both cases, white patches may appear in the oral cavity. Aphthae, however, are simply an overreaction of the immune system to stress or an illness and usually disappear within two weeks if left untreated. Oral cavity cancer, on the other hand, gets worse instead of better if left alone.

Read more: Oral aphtae

Advanced stage

If oral cavity cancer is not recognised at an early stage, the symptoms worsen and new ones can develop:

• Open sores
• Lumps
• Tiredness/Lethargy
• Loss of appetite
• Reduced capabilities
• Loss of weight
• Metastases in the cervical lymph nodes and other organs
• Tumour breaks through the skin or grows into the jawbone

Where does oral cavity cancer occur?

Oral cavity cancer can develop anywhere in the oral cavity. The following types of oral cavity cancer exist:

• Tongue cancer (technical term: squamous cell carcinoma of the tongue)
• Lip cancer (technical term: squamous cell carcinoma of the lips)
• Gum cancer (technical term: squamous cell carcinoma of the gingiva)
• Floor of the mouth cancer (technical term: squamous cell carcinoma of the floor of the mouth)
• Roof of the mouth cancer (technical term: squamous cell carcinoma of the palate)
• Jaw bone cancer (technical term: squamous cell carcinoma of the jaw bone)
• Tonsil cancer (technical term: squamous cell carcinoma of the tonsils)
• Salivary gland cancer (technical term: parotid gland tumour)

Oral cavity cancer can also develop on the inside of the cheeks. However, there is no technical term for this type of oral cavity cancer.

Causes and risk factors: What causes oral cavity cancer?

The exact causes of oral cavity cancer are not yet fully known. Medical professionals suspect that a hereditary component is involved. That said, it has been scientifically proven that certain lifestyle habits greatly increase a person's risk of developing oral cavity cancer. In exceptional cases, however, oral cavity cancer can also start for no apparent reason.

Oral cavity cancer due to smoking and drinking alcohol

Smokers who drink alcohol regularly are 30 times more likely to get oral cavity cancer than those who do not use tobacco and consume very little alcohol. This is because the nitrosamines in cigarette smoke can penetrate the cells and alter their genetic material. However, not every smoker develops oral cavity cancer, and not every oral cavity cancer patient is a smoker. Around 25 per cent of those affected by the disease do not fall into this risk group.

Poor oral hygiene and irritation of the oral mucosa

Poor oral hygiene and constant irritation of the oral mucosa – for example due to poorly fitting dentures, dental fillings or sharp teeth – are also possible causes of oral cavity cancer. 

Human papillomaviruses (HPV) 

Human papillomaviruses (HPV) have been found in some oral tumours. These HPVs are primarily known to cause cervical cancer and can be transmitted through oral sex. Male smokers who have had five or more female oral sexual partners have an increased risk of developing oral cavity cancer. HPV infections are the main cause of oral cavity cancer in people under the age of 30. They are a particularly common cause of oral cavity cancer of the throat and tonsils. Roughly 70 per cent of carcinomas in these cases are HPV related. 

Read more: What to do in case of HPV infection?

Poor diet

A poor diet can also put you at risk of developing oral cavity cancer. This applies in particular to a diet with a high intake of meat and charred and heavily fried foods. Frying and grilling foods containing nitrite, such as cured meat or sausages, can produce carcinogenic nitrosamines. 

Diagnosis: How do doctors detect oral cavity cancer?

If you have the slightest suspicion that you might be suffering from oral cavity cancer, consult a doctor as early as possible to prevent the disease from spreading around your body. Discover everything you need to know about diagnosing cancer earlier below:

Which doctor should you see if you suspect oral cavity cancer?

Dentists, ENT specialists and orthodontists often recognise abnormalities in the oral cavity during routine check-ups or treatment for other oral diseases. If there is any suspicion of oral cavity cancer, you can first go and have it rechecked by your family doctor. They will then refer you to an ENT specialist or an oncologist – a doctor who specialises in the treatment of cancer. Some dentists and oncologists also offer special medical examinations for early detection. Your family doctor should be your first port of call to discuss any concerns you might have.

Which examinations are performed to diagnose oral cavity cancer?

If oral cavity cancer is suspected, the doctor will first examine your mouth and throat using an endoscope and take a small sample of tissue (biopsy) to determine whether tumour cells are present or not. The sample of tissue can be used to identify whether a tumour has already grown or whether the oral cavity cancer is still in the early stages, what type of tumour is involved and how aggressive it is.

The following additional examinations can be employed to determine the severity of the tumour and to detect possible metastases:

• CT (computed tomography) or MRI (magnetic resonance imaging) scans of the neck and the actual tumour
• US (ultrasonography) scans of the cervical lymph nodes
• X-ray images of the upper and lower jaw

The doctor will decide which diagnostic procedures are best for your condition. 

Classification of the tumour

The type of treatment and the chances of recovery depend primarily on the size of the tumour and whether or not it has spread at the time of diagnosis and the actual properties of the tumour tissue.

Determination of similarity with normal oral mucosal cells

The greater the similarity between the cancer cells and the normal healthy cells, the better your chances of treatment being successful. Medical professionals distinguish between four grades of tumour:

• G1: The cancer cells still generally resemble normal healthy cells. This means that the tumour is less aggressive and malignant.
• G2: The cancer cells no longer look like normal healthy oral mucosal cells; the tumour is malignant.
• G3: The cancer cells have little similarity with the healthy tissue and the tumour is malignant and aggressive. Metastases may develop.
• G4: The tumour is very malignant and the tumour tissue no longer resembles normal tissue. It tends to grow very fast and can also form metastases. 

TNM classification

Medical professionals around the world also use the TNM classification to determine the size of the tumour and the presence of lymph node involvement and metastases.

Tumour size (T):

• T0: No evidence of a tumour
• TiS: Preliminary stage of oral cavity cancer that only affects the uppermost cell layer
• T1: Tumour is 2 cm across or less
• T2: Tumour is between 2 and 4 cm across
• T3: Tumour is more than 4 cm across
• T4: Tumour has spread into neighbouring tissue (e.g. vessels, nerves or bones); irrespective of its size. 

Lymph nodes affected (N):

• N0: No lymph nodes with cancer.
• N1: Cancer has spread to a lymph node
• N2: Cancer has spread to several lymph nodes.

Metastases (M):

• M0: No metastases have been found.
• M1: Metastases have formed.

The lower the TNM score, the higher the chances of treatment being successful, as the tumour is then still small and localised without metastases.

Treatment of oral cavity cancer

The most suitable treatment is not approved by just one doctor but by a team of specialists from the following disciplines:

• Oral and maxillofacial surgery
• Odontology
• Ear, nose and throat surgery
• Radiotherapy
• Oncology
• Pathology
• Radiology
• If necessary: Neurosurgery and plastic surgery

In specialist clinics for oral cavity cancer, specialists meet at regularly scheduled multidisciplinary tumour conferences to discuss the cases of individual patients and to recommend the best therapeutic strategies. However, the final decision always lies with the patient.

An overview of the common forms of treatment for oral cavity cancer is presented below. For more details, refer to the “blue advisor” (blaue Ratgeber) published by German Cancer Aid (Deutsche Krebshilfe) or the patient guidelines on oral cavity cancer (Patientenleitlinie Mundhöhlenkrebs) – a comprehensive brochure crafted for patients by the Association of Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften e. V., AWMF), in collaboration with the German Cancer Society (Deutsche Krebsgesellschaft e. V., DKG) and German Cancer Aid (Deutsche Krebshilfe, DKH). These documents also include important information about patients' rights.

Curative care and palliative care

If the cancer is still in the early stages and has not grown, the chances of recovery are good. This is referred to as curative care or treatment. In other words, the aim of treatment is to remove the tumour fully.

However, if the oral cavity cancer is already so advanced that it is incurable, for example because metastases have formed in vital organs and the disease is in its final stage, it is referred to as palliative care or treatment. In this case, the aim is not to remove the tumour and battle the cancer but to improve a patient’s quality of life and to focus on relieving their symptoms and prolonging their life. This is where, for example, drugs are used to stop the growth of the tumour (chemotherapy). 

Surgery and reconstruction with oral cavity cancer

Curative treatment of oral cavity cancer generally involves the surgical removal of the tumour under general anaesthetic. To be on the safe side, surgeons must also remove part of the healthy tissue. If all of the tumour can be safely removed during surgery, there is a good chance of it not coming back. And if the cancer has already spread to the lymph nodes, they are also taken out. Surgeons regularly remove the cervical lymph nodes on the affected side as a precautionary measure, even if no cancer cells have been found. Hidden lymph node metastases occur in about 20 to 40 per cent of patients with oral cavity cancer and are so small that they cannot be detected on scans.

Reconstruction of the affected area is often performed during the same surgical procedure. Wherever possible, surgeons take your own tissue from another part of the body, i.e. skin, muscle or bone, and transplant it to the area needing repair. In some cases, parts made of plastic or metal are also used. On the one hand, the aim of reconstruction is to ensure that essential functions, such as chewing, speaking, breathing and swallowing, can continue or be quickly restored after surgery; on the other hand, surgeons also try to restore the patient’s external appearance as far as possible. That said, it is not always possible to remove a tumour and perform reconstructive surgery during the same procedure. Sometimes one or several follow-up surgical procedures are necessary after the initial operation.

If the tumour cannot be removed fully, surgery is usually followed by radiotherapy and/or chemotherapy.

Radiation therapy for oral cavity cancer

Radiotherapy is a key measure in curative treatment and can be used either alone or in combination with surgery or chemotherapy. It helps boost the chance of recovery. Moreover, it involves a radiotherapist aiming high-energy X-rays directly at the tumour, thereby ensuring the cancer cells can no longer divide and ultimately die. Lower-intensity radiation is delivered to the tissue around the tumour. The radiotherapy treatment is divided into several sessions spread out over days or weeks – usually five times a week over a period of five to seven weeks.

Radiotherapy can also negatively affect nearby healthy cells. However, state-of-the-art technology allows the beams to be targeted directly at the tumour, therefore primarily killing the cancer cells. The individual treatment sessions normally last just a few minutes.

Usually, radiation is given through the skin to the area affected. In individual cases – with very small, slow growing tumours – radiotherapy can also be administered from inside the body.

Possible side effects of radiotherapy:

• Irritation of the skin and oral mucosa
• Dry mouth
• Altered taste sensation
• Difficulty swallowing
• Fluid retention
• Tiredness
• Headache
• Gastrointestinal problems
• Impaired fertility

Radiotherapy may also increase your risk of developing a second tumour.

Medical treatment of oral cavity cancer

In terms of medical treatment therapies, a distinction is made between chemotherapy and immunotherapy. In fact, both forms of therapy can be applied simultaneously as chemoimmunotherapy.

Chemotherapy

Chemotherapy involves patients being given drugs that prevent cell division and ensure that the tumour cannot spread further. In curative care, chemotherapy can be used alongside surgery or radiation therapy, and in palliative care it is the sole treatment. Chemotherapy is usually given in a hospital. Generally, the drugs are administered intravenously over a period of several days. The treatment is repeated at certain intervals – with two to three week breaks in between. The length of chemotherapy treatment is determined by how the tumour responds to it and how the patient tolerates it.

Chemotherapy destroys all rapidly dividing cells indiscriminately, meaning a large proportion of cancerous cells are affected but unfortunately so are healthy ones. Chemotherapy can, therefore, cause a number of side effects:

• Vomiting, nausea and diarrhoea
• Loss of hair
• Skin problems
• Infections of the oral mucosa
• Exhaustion and tiredness
• Weakened immune system
• Low number of red or white blood cells, poor blood cell count
• Damage to kidneys, liver, bone marrow and hearing
• Dry mouth
• Salivary gland dysfunction

Immunotherapy

Immunotherapy is used alone or alongside chemotherapy in the palliative care of oral cavity cancer patients. Rather than attacking cancer cells, immunotherapy works by activating the body's own immune system response against tumours. In cancer patients, the cancer cells have developed unique traits to evade the immune system and multiply unrecognised. To do so, they upregulate "checkpoint" molecules, which then prevent immune cells from attacking cancer cells. The drugs used in immunotherapy contain antibodies that can block checkpoints and thus expose the cancer cells to the immune system. This allows the immune system to recognise the cancer cells and to destroy them. Patients are also given the drugs intravenously.

Medical professionals expect immunotherapy to have fewer side effects on healthy cells than chemotherapy. Nevertheless, substantial side effects are not uncommon:

• Skin rashes
• Itching
• Magnesium deficiency
• Fever
• Chills
• Dizziness
• Shortness of breath
• Infection of the oral mucosa
• Elevated liver values
• Headache
• Diarrhoea, nausea and vomiting

Rehabilitation 

Treatment for oral cavity cancer is usually followed by rehabilitation – also known as rehab – to prepare patients both physically and mentally for a return to their everyday lives. Rehab can take place either in a specialised rehab clinic or on an outpatient basis. As a rule, a stay in a rehab clinic lasts three weeks. A team of experts specialising in physiotherapy, psychology, medicine, nursing and social work put together a programme to help people transition back into everyday life. The agenda includes, for example, exercise therapy, relaxation techniques, nutritional counselling, psychological support and group therapy, as well as further information about the disease. 

After-care

Seeing as oral cavity cancer can come back even after successful surgery or radiotherapy, it is important that patients attend regular after-care examinations to ensure that any recurrences or secondary cancers (metastases) can be detected and treated as early as possible. The after-care examinations can be performed by your family doctor or a clinical oncologist.

Supporting treatment measures

Cancer treatment is not just about fighting the tumour but also about keeping any side effects of the treatment to an absolute minimum. The following treatments, therefore, often go hand in hand with cancer treatment:

Dental treatment    

The most common side effects of radiotherapy for oral cavity cancer include infections of the oral mucosa and permanent dry mouth. Moreover, teeth, jaw bones and salivary glands may be damaged. If the salivary glands are permanently damaged, the effectiveness of saliva in maintaining a relatively neutral pH in the oral cavity is lost and a patient’s teeth are generally more susceptible to dental decay (radiation caries). If teeth have to be extracted during treatment, healing of the tooth socket may take longer than normal. It is, therefore, crucial that a dentist thoroughly examines and prepares the oral cavity prior to treatment: The dentist will remove plaque and tartar, fit dental fillings and, if necessary, extract teeth.

Important: Denture wearers should not wear their dentures during cancer treatment. This helps prevent the development of poorly healing pressure points.

Diet for oral cavity cancer patients

Infections and pain in the oral mucosa are not uncommon during oral cavity cancer treatment, making eating and chewing somewhat difficult. During this time, those affected should eat mainly pureed and soft foods and stay clear of acidic foods, such as oranges and lemons. Patients may also need to be fed intravenously for a short period of time.  

Speech therapy  

Surgery for the treatment of oral cavity cancer can also affect a person's ability to speak properly. Furthermore, they may experience problems swallowing. This is especially the case if parts of the tongue have had to be removed. Speech therapy is, therefore, often an integral part of cancer treatment and aims to restore the ability to speak properly.

Psycho-oncology support

Being diagnosed with cancer can be a huge shock, with many people experiencing anxiety and depression. Thankfully, psycho-oncologists are usually on hand to help. Psycho-oncologists offer a specialist psychological care service for people affected by cancer. Those affected often benefit from sharing their experiences of cancer as well as their fears and worries with a trusted health care professional. Family and friends can also be integrated in the psycho-oncology support of patients.

Additional care offers

There are numerous support organisations that provide comprehensive information about cancer and also offer assistance in everyday life and with any legal issues that may emerge. These include, for example, self-help groups, social services and cancer counselling charities. Moreover, there are also special programmes for relatives of people with cancer. Private health insurance companies and support organisations are able to signpost you to further services. 

Preventative measures: What you can do to prevent oral cavity cancer

Fortunately, there are a number of things you can do to prevent oral cavity cancer from developing in the first place. Remember, you have full control over the main causes: 

Quit smoking and drink less alcohol

Smokers who drink alcohol regularly – as previously mentioned – are 30 times more likely to get oral cavity cancer than those who do not use tobacco and consume very little alcohol. If you smoke and consume alcoholic drinks on a regular basis, you should perhaps consider kicking these habits.

Smoking not only increases the risk of developing oral cavity cancer but is actually top of the list of risk factors for all oral and dental diseases – from dry mouth to dental decay and periodontitis. Your lungs will also breathe a huge sigh of relief if you stop smoking, and your liver will be happy about the extended breaks from detoxifying alcohol.   

Thorough oral hygiene

Poor oral hygiene is also a risk factor when it comes to oral cavity cancer. Although toothbrushing is something we do every day, there are so many mistakes you can make – often without even knowing. We have put together an overview of the main elements for thorough oral hygiene below:

• Brush your teeth at least twice a day for three minutes each time, ideally in the morning after breakfast and at night before going to bed.
• Position the brush at a 45-degree angle where the teeth meet the gums and at an upward sloping angle in the upper jaw and a downward sloping angle in the lower jaw, making sure that half of the filaments always sit across your gums and the other half over your teeth.
• Brush your teeth from one side to the other gently and with very little pressure, using small, circular movements (in the upper and lower jaw focussing on the inner, outer and chewing surfaces)
• Use a soft toothbrush and a fluoride toothpaste to clean your teeth
• Clean the spaces between your teeth at least once a day with an interdental brush
• Clean your tongue once a day with a tongue scraper 

Regular check-ups

In addition to brushing your teeth thoroughly at home, you should also go and have your teeth examined regularly by a dentist. Since the trained eyes of a medical professional are more likely to recognise abnormalities in the oral mucosa than you are. Your dentist might even recommend having the area checked out by an ENT specialist.

Oral cavity self-examination

Check your oral cavity regularly for any signs of change. This applies in particular to white, red or grey spots that cannot be wiped off, as well as rough or hardened patches. As previously mentioned, have such spots checked by a doctor if they fail to disappear by themselves within 14 days.

The initiative "Let’s Talk About Mouth Cancer" recommends an easy 5-point check. All you need is your hands and a mirror:

1. Pull your lips up or down and look for any lumps, bumps or changes in texture.
2. Pull out your cheeks to look on the inside. Look for any white or red patches and use your thumb and forefinger to check for ulcers, lumps or tenderness.
3. Stick your tongue out and look at the surfaces for any changes in colour and texture. Pull your tongue out and look at both sides then lift the tip of your tongue to examine the underside.
4. Examine the floor of your mouth. Lift the tip of your tongue to the roof of your mouth and tilt forward your head. Gently press your index finger along the floor of your mouth to feel for any lump, bumps, swellings or ulcers.
5. Tilt back your head and open your mouth wide to check the roof of your mouth.