Quick answer. Oral cancer is cancer of the mouth or tongue, and its most important warning sign is a mouth ulcer, lump, or red or white patch that does not heal within about three weeks. Smoking, alcohol and betel nut chewing raise the risk, and seeing a doctor or dentist early gives the best chance of successful treatment.
Oral cancer refers to cancer that develops in the mouth, including the tongue, the lips, the gums, the inner cheeks and the floor and roof of the mouth. The most important thing to know is that a mouth ulcer, lump or patch that does not heal within about three weeks should be checked by a doctor or dentist. Caught early, oral cancer is often very treatable, but its early signs can be easy to dismiss as a harmless ulcer.
This guide explains what oral cancer is, the signs and symptoms to look out for, the main risk factors, how it is diagnosed and how it is treated in Singapore. It is general information, not a diagnosis. The single most useful action you can take is to get any persistent, non-healing mouth sore or patch examined promptly, rather than waiting to see if it goes away.
At a glance
| Sign | What to look for | What to do |
|---|---|---|
| Non-healing ulcer | A mouth ulcer or sore that does not heal within about three weeks | See a doctor or dentist |
| A lump | A lump or thickening in the mouth, tongue, lip or neck | Get it examined |
| Red or white patches | Persistent red or white patches in the mouth | Have them checked, as they can be pre-cancerous |
| Persistent symptoms | Ongoing sore throat, hoarseness, or difficulty swallowing | See a doctor, especially if combined with risk factors |
| Unexplained changes | Numbness, loose teeth, or bleeding in the mouth with no clear cause | Get it assessed |
What is oral cancer?
Oral cancer, also called mouth cancer, is a cancer that starts in the tissues of the mouth, most often on the tongue or the floor of the mouth, but also on the lips, gums, inner cheeks and the roof of the mouth. The great majority are a type called squamous cell carcinoma, which begins in the flat cells lining the mouth.
It is more common in older adults and in people with certain lifestyle risk factors. Oral cancer is an important issue in Singapore and the wider region, partly because some risk factors, such as betel nut chewing, are present in the community. The encouraging point is that the mouth is easy to examine, so oral cancer can often be picked up early during a dental or medical check, when treatment tends to be most effective.
Symptoms & signs
The warning signs of oral cancer include:
- A mouth ulcer or sore that does not heal within about three weeks
- A lump or thickening in the mouth, on the tongue, lip, or in the neck
- Persistent red or white patches in the mouth
- Ongoing pain or discomfort in the mouth
- Difficulty or pain when chewing or swallowing
- A persistent sore throat, hoarseness or a feeling of something stuck in the throat
- Numbness, loose teeth, or unexplained bleeding in the mouth
- A lump in the neck that does not go away
Many of these symptoms have harmless causes, such as ordinary mouth ulcers or minor infections, which usually settle within a couple of weeks. It is the persistence – a sore that lingers beyond three weeks – that should prompt a check.
Causes & risk factors
Several factors raise the risk of oral cancer, and many are avoidable:
- Smoking and other tobacco use, including chewing tobacco
- Heavy alcohol use, especially combined with smoking, which multiplies the risk
- Betel nut (areca nut) chewing, a significant risk factor in parts of the region
- Infection with certain types of HPV (human papillomavirus)
- Prolonged sun exposure, which raises the risk of lip cancer
- Being older, and a previous history of mouth cancer
- A diet low in fruit and vegetables
Avoiding tobacco, betel nut and excess alcohol substantially lowers the risk. Regular dental check-ups also help, because dentists can spot suspicious changes early.
How it's diagnosed
If oral cancer is suspected, a doctor or dentist will examine your mouth, tongue and neck carefully. The key test is a biopsy, where a small sample of the suspicious area is removed and examined under a microscope to confirm whether cancer is present.
If cancer is confirmed, further tests such as CT, MRI or other scans may be done to find out the size of the cancer and whether it has spread to the lymph nodes in the neck or beyond. This staging information helps the team plan the most appropriate treatment. A persistent mouth ulcer or patch is worth getting biopsied rather than simply watched, as this is the only way to be certain of the cause.
Treatment options
Treatment depends on where the cancer is, its size and stage, and your general health, and is usually planned by a team. The main options are:
- Surgery to remove the cancer, sometimes along with affected lymph nodes in the neck. Reconstructive surgery may be used to restore appearance and function.
- Radiotherapy, which uses targeted radiation to destroy cancer cells, used alone or alongside surgery.
- Chemotherapy, sometimes combined with radiotherapy, particularly for more advanced disease.
- Targeted therapy or immunotherapy in selected cases.
Early-stage oral cancer often needs less extensive treatment and has better outcomes, which is why early detection matters so much. Support such as speech and swallowing therapy and dental care may be part of recovery. Costs vary with the treatment and setting, so ask your care team for a clear estimate.
When to see a doctor & which specialist
The clearest rule is this: a mouth ulcer, lump, or red or white patch that has not healed within about three weeks should be checked by a doctor or dentist. Do not wait longer to see if it clears – persistent changes need examination, even if they are not painful. This is even more important if you smoke, drink heavily or chew betel nut.
Also see a doctor for ongoing difficulty swallowing, a persistent hoarse voice or sore throat, unexplained bleeding or numbness in the mouth, or a lump in the neck that does not go away. If you have sudden severe difficulty breathing or swallowing, seek urgent care or call 995. For assessment of suspicious mouth and throat changes, the specialist to see is an ENT (ear, nose and throat) surgeon, and if cancer is confirmed an oncologist will also be involved. You can find specialists through our directories of the best ENT specialists in Singapore and the best oncologists in Singapore.
Related guides
- Best ENT Clinics in Singapore — our editorial shortlist
- ENT clinics directory
- Kidney cancer
- Roseola
- Baby reflux
- Scarlet fever
- Polymyalgia rheumatica
Sources
- NHS – Mouth cancer
- Mayo Clinic – Mouth cancer
- HealthHub Singapore – Cancer
- National Cancer Centre Singapore
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