Mouth cancer

Mouth cancer is a malignant tumour arising from the lining of the mouth: the tongue, the floor of the mouth beneath it, the gums, the inside of the cheeks, the palate and the lips. It is also called oral cancer. This tumour has a feature rare in oncology: it grows in plain sight. It can be seen in a mirror and felt with the tongue long before it starts to get in the way, and the outcome most often turns on whether somebody paid attention to a sore that would not heal. Found early, it is curable in most cases and leaves almost no trace; found late, it calls for major surgery and does not always yield.

What the disease is and who it affects

Almost all tumours of the mouth develop from squamous epithelium, the layer of cells covering the lining. The side of the tongue and the floor of the mouth beneath it are the commonest sites; on the lip the tumour is usually sun-related and behaves more quietly.

Risk rises with age: most people affected are over sixty, though tumours in non-smokers in their forties are becoming more frequent. Men are affected considerably more often than women.

How serious it is depends above all on the size of the tumour when it was found and on whether it has reached the lymph nodes in the neck. The difference between a patch the size of a pea and a lump in the neck is the difference between minor surgery and months of treatment.

Pre-cancerous changes are worth knowing about separately. A white patch that cannot be rubbed off (leukoplakia), and above all a red, velvety patch (erythroplakia), are not cancer, but they mark an area where cancer may arise. Such patches are monitored and sometimes removed in advance.

Changes in the mouth that should raise concern

The main sign is an ulcer or sore that has not healed after three weeks. An ordinary aphthous ulcer, a bitten cheek or a burn from hot food heals in a week or ten days. Anything lasting longer should be shown to a doctor even if it is painless: in the early stages this tumour usually does not hurt at all.

The other things worth noticing:

• a red or white patch on the lining that does not go away;
• a lump, swelling or thickening in the mouth, on the lip or in the neck;
• pain always in the same spot in the mouth, spreading to the ear, particularly on swallowing;
• numbness of the lip, chin or part of the tongue;
• teeth that have started to loosen for no reason, or a denture that has suddenly stopped fitting;
• bleeding from one particular area unconnected with brushing;
• difficulty swallowing, or a mouth that will not open as wide as it did;
• hoarseness lasting more than three weeks, or unexplained weight loss.

All these signs are far more often caused by something harmless: a denture rubbing, a sharp edge of a tooth, inflammation, a viral infection. A symptom on its own does not mean cancer. But neither a patient nor a search engine can tell one from the other by eye, so a doctor has to look.

The three-week rule: who to see and what happens at the appointment

Three weeks is the line beyond which waiting stops being reasonable. The count runs not from the day it began to hurt but from the day the change appeared.

A dentist, a family doctor or an ear, nose and throat specialist will all do — what matters is not the speciality but that the whole mouth is examined. A dentist looks at the lining more often than any other clinician, and a check-up every six to twelve months is the most reliable way of catching this tumour early.

At the appointment the doctor will ask about smoking, alcohol and how long the change has been there, look inside the mouth in good light, move the tongue and cheeks aside, feel the floor of the mouth from inside and outside, and always feel the neck. The examination takes a couple of minutes and is not painful. If there is any doubt you will be referred to a maxillofacial surgeon or an oncologist — a referral by itself is not a diagnosis.

An ambulance is needed (in Spain, Italy, Portugal, Poland and Ukraine the single European number is 112) if:

• there is heavy bleeding from the mouth that cannot be stopped;
• breathing has become difficult or noisy on breathing in;
• the person cannot swallow their own saliva.

What raises the risk

The exact cause in an individual can rarely be named, but the range of causes is known and unusually predictable for a cancer.

Tobacco in any form comes first: cigarettes, roll-ups, a pipe, a waterpipe, and the chewed forms too — chewing tobacco, betel quid and paan. Chewed mixtures are more dangerous than they seem because they sit against the same spot on the cheek for hours.

Alcohol comes second, particularly spirits taken regularly. And third, importantly: tobacco and alcohol together raise the risk not by addition but several times more than either alone, because alcohol helps carcinogens penetrate the lining.

What else counts:

• human papillomavirus — certain types are linked with tumours of the mouth and especially of the throat;
• sunlight on the lower lip: lip cancer is markedly commoner in people who work outdoors;
• pre-cancerous patches — leukoplakia, erythroplakia and some forms of oral lichen planus;
• a weakened immune system — after an organ transplant, with HIV, or on long-term medicines that suppress immunity;
• a previous head or neck cancer;
• a poor diet with few vegetables and fruit;
• constant injury to the lining from a sharp tooth edge or a badly fitting denture.

What genuinely lowers the risk

There is no complete insurance, but here, unlike with many cancers, the scope for changing the odds is enormous: giving up tobacco and moderating alcohol remove most of the chance of ever developing it. What is worth doing:

• stop smoking and give up chewing tobacco, betel and paan — the risk starts falling within a few years and keeps falling;
• cut down on alcohol, or better still stop;
• protect the lips: a lip balm with a sun filter, and a wide-brimmed hat for outdoor work;
• get teeth and dentures sorted so that nothing rubs the lining day after day;
• have the human papillomavirus vaccine if it is appropriate for your age and you have not had it — the timing and eligibility are set by the national immunisation schedule;
• eat more vegetables, fruit and greens;
• see a dentist every six to twelve months even when nothing is troubling you.

A useful habit is to look inside your own mouth once a month: in good light, pull the cheeks aside, lift and turn the tongue, inspect the floor of the mouth and run a finger over it. It takes a minute, and knowing what your own lining normally looks like is what makes anything new stand out.

How the diagnosis is confirmed

The only way to make the diagnosis is a biopsy: a piece of tissue is taken from the suspicious area and examined under the microscope. Everything else only fills in the picture. No blood test detects mouth cancer, and tumour markers are not used for it.

An ordinary dental X-ray does not show a tumour in the lining either: X-rays see bone, not soft tissue. It is done for a different purpose — to check whether the tumour has grown into the jaw, and to assess the teeth before treatment.

Once the diagnosis is confirmed, the next question is how far the tumour has spread. For that:

• an MRI scan, which shows the borders of the tumour in soft tissue best of all;
• a CT scan of the head, neck and chest;
• an ultrasound of the neck, with a needle sample from a suspicious node if required;
• sometimes a PET scan;
• testing the tumour tissue for human papillomavirus — this affects both the outlook and the choice of treatment.

Waiting for results is the hardest part. It is worth agreeing beforehand who will give them and how, and not going to that conversation alone: two people remember considerably more.

How it is treated and what follows

The plan depends on the size and site of the tumour, on whether the lymph nodes are involved, and on age and other conditions. The decision is made by a team: a surgeon, a radiation oncologist, a medical oncologist, a dentist, a speech and language therapist and a dietitian.

Surgery is the mainstay. The tumour is removed with a margin of healthy tissue around it, often together with the lymph nodes of the neck. If a large part of the tongue or jaw has to go, it is rebuilt with tissue from elsewhere in the body during the same operation.

Radiotherapy is used both as treatment in its own right for small tumours and after surgery to reduce the chance of return. Chemotherapy usually runs alongside radiotherapy, or is used when the tumour has spread; for recurrence and secondaries, targeted drugs and immunotherapy are also used.

One thing is worth knowing in advance: the teeth are put in order before radiotherapy begins, not after. An irradiated jaw heals badly, and taking a tooth out after radiotherapy can lead to a serious complication. A dentist should examine the mouth before the first session.

Treatment leaves after-effects that are dealt with in their own right: a dry mouth, altered taste, difficulty with speech and swallowing, restricted opening of the mouth. Exercises with a speech and language therapist, mouth care and saliva substitutes all help. Stopping smoking after treatment reduces the chance of a second tumour more than any medicine does.

If the tumour is found late and cannot be cured, treatment still continues: it holds back growth, relieves pain and makes swallowing easier. That is the work of the palliative care service, and it is worth involving them early.

Online consultation

Looking inside a mouth and feeling a neck cannot be done through a screen, so anything suspicious always needs an examination in person. A remote appointment, though, is useful in the approach to that.

It helps settle the main question — wait or go. The doctor will go through how long the change has been there, whether a tooth or denture is rubbing next to it, and what the history with smoking and alcohol has been, and will say whether to be seen today, in a week, or whether it is reasonable to keep an eye on it. A good photograph taken in bright light often adds a great deal.

The second use is support along the way. A video call is a convenient way to explain what a report means, which specialist to see next, what tests are needed before the appointment, how to manage a dry mouth and pain after treatment, and what to eat when swallowing is hard. Going through a plan drawn up by another doctor, and asking the questions there was no time for at the face-to-face appointment, is an ordinary reason for such a conversation. For heavy bleeding from the mouth or difficulty breathing, the call goes to an ambulance.

This material is for information only and does not replace medical advice.