In shortOral cancer is malignancy of the lips, tongue, floor of the mouth, cheek lining, gums, or palate, most often squamous cell carcinoma. Early lesions are frequently painless, which is why they are missed. The most useful single rule for the public is that any ulcer, white or red patch, or lump persisting beyond three weeks needs professional examination — early detection changes outcomes dramatically.
Why early detection matters so much here
Outcomes in oral cancer are strongly stage-dependent, and the gap between early and late diagnosis is among the widest in oncology. Yet a substantial proportion of cases are diagnosed late, and the reason is rarely that the lesion was hidden — it is that it did not hurt. Patients wait because pain is the signal they are watching for, and early oral cancer frequently produces none.
Persistence, not pain, is the criterion to act on. Ordinary oral
ulcers heal within about two weeks. A traumatic ulcer heals once its cause is removed. Anything still present after three weeks has failed the test that most benign lesions pass easily, and that is the point to have it examined regardless of whether it hurts, how small it is, or how plausible your explanation for it seems.
Signs and symptoms to know
- An ulcer or sore that has not healed in three weeks.
- A red patch (erythroplakia) or a white patch — see leukoplakia — that persists.
- A lump or thickening in the cheek, tongue, or neck.
- Persistent numbness of the lip, tongue, or a tooth without a dental explanation.
- Unexplained bleeding from the mouth.
- Difficulty or discomfort on swallowing, chewing, or moving the tongue or jaw.
- A persistent sore throat or the sensation of something caught, without infection.
- A change in the way dentures fit, or teeth becoming loose without periodontal cause.
- Hoarseness lasting more than a few weeks.
Risk factors
| Factor | Note |
|---|
| Tobacco, all forms | The dominant risk factor; smokeless products carry high risk too |
| Alcohol | Synergistic with tobacco — combined use multiplies rather than adds |
| Betel quid, areca nut | Major factor in several regions |
| HPV (types including 16) | Increasingly relevant, particularly oropharyngeal sites |
| Sun exposure | Specifically for lip cancer |
| Age over 40, male sex | Higher incidence, but incidence in younger non-smokers is rising |
| Previous oral cancer | Elevated risk of a second primary — lifelong surveillance |
No risk factor does not mean no risk. A growing share of cases occurs in younger patients who neither smoke nor drink heavily, and the practical consequence is that a persistent lesion in a healthy non-smoker deserves exactly the same three-week rule. Dismissing a non-healing ulcer because you do not fit the classic profile is one of the more common reasons for delay.
A monthly self-examination, done properly
- Good light and a mirror. Remove any dentures first.
- Lips — outside and inside, pulling each lip away from the teeth.
- Cheek lining — pull each cheek out and look at the whole surface.
- Tongue — top, then both lateral borders by moving it side to side, then the underside by lifting the tip to the palate. The lateral border and underside are high-risk sites and the ones most often skipped.
- Floor of the mouth — lift the tongue and look, then feel with a fingertip for any firm area.
- Palate — hard and soft, tilting the head back.
- Neck — feel along both sides and under the jaw for lumps, comparing left with right.
Report anything that persists beyond three weeks. Self-examination is a supplement to professional examination, not a replacement — a routine dental check-up includes a soft tissue examination, which is one of the underappreciated benefits of attending regularly even when nothing hurts.
What assessment involves
Examination and palpation come first, followed by biopsy, which is the only way to establish a diagnosis; no visual method substitutes for histology. Imaging determines extent and nodal involvement, and treatment is planned by a multidisciplinary team, typically combining surgery, radiotherapy, and in some cases chemotherapy. Dental input before cancer treatment genuinely matters: teeth that will cause problems are best addressed before radiotherapy begins, because extractions in irradiated bone carry a considerably higher complication risk afterwards. If a diagnosis is being made, ask whether a pre-treatment dental assessment has been arranged.
This page is general health information, not a diagnosis, and nothing here can determine what a specific lesion is. The overwhelming majority of persistent mouth lesions turn out to be benign. The purpose of the three-week rule is not to alarm but to remove the guesswork: it is a threshold at which to seek examination, not a prediction. If you have a lesion that meets it, arrange to be seen rather than searching for a more comfortable explanation.
Notes for patients based in Korea
If you are here on a posting, a persistent oral lesion is not something to save for your next home visit. Prompt examination and, where indicated, biopsy is available locally, and delay is the one variable that consistently worsens outcomes. We are approximately 30 minutes from Camp Humphreys, consultations and explanations are provided in English, and we can arrange onward referral with English documentation where specialist care is needed. Book an examination without waiting if you have a lesion older than three weeks.
Frequently asked questions
What is the single most important warning sign?
An ulcer, patch, or lump that has not healed within three weeks. Ordinary mouth ulcers resolve in about two weeks and traumatic ulcers heal once the cause is removed, so persistence beyond three weeks is the criterion to act on. Crucially it applies whether or not the lesion hurts, since early oral cancer is frequently painless.
Does oral cancer hurt in the early stages?
Often not, and this is precisely why cases are diagnosed late. Patients wait for pain as their signal to seek care, while an early painless lesion progresses quietly. Basing your decision on duration rather than discomfort is the practical correction, because a painless ulcer that has lasted a month warrants examination just as much as a painful one.
I do not smoke or drink. Am I at risk?
Your risk is lower but not absent, and a growing proportion of cases occurs in younger patients without the classic risk factors, some HPV-associated. The practical implication is that the three-week rule applies to you identically. Dismissing a persistent lesion because you do not fit the expected profile is a recognised cause of diagnostic delay.
Where in the mouth should I check most carefully?
The lateral borders and underside of the tongue and the floor of the mouth are higher-risk sites, and they are also the areas people skip because seeing them requires deliberately moving the tongue and lifting it to the palate. Include the soft palate, the whole cheek lining, and both sides of the neck. Do it monthly in good light with dentures removed.
Can a dentist detect oral cancer at a routine check-up?
A routine examination includes inspection and palpation of the soft tissues, and dentists do detect early lesions this way, frequently in patients who had noticed nothing. That is one of the underappreciated reasons to attend regularly even with no symptoms. Definitive diagnosis always requires biopsy, since no visual or light-based screening method replaces histology.
Should I see someone before cancer treatment starts?
Yes, a pre-treatment dental assessment is genuinely important. Teeth likely to cause problems are best dealt with before radiotherapy, because extractions in irradiated bone carry a substantially higher risk of complications afterwards. Ask whether this has been arranged, since it is occasionally overlooked amid the urgency of starting oncological treatment.