Mouth cancer: symptoms worth showing a dentist, risk factors and how diagnosis works

What symptoms can mouth cancer cause?

Mouth cancer can make itself known through a change that does not go away. The symptoms on the list are named by the UK’s National Health Service (NHS), the charity Cancer Research UK and the US National Institute of Dental and Craniofacial Research (NIDCR). The NHS and the UK NICE guideline regard an ulcer that has not healed for more than 3 weeks as a signal for urgent assessment, and the NIDCR advises having any of these symptoms checked if it lasts more than 2 weeks.

These same symptoms are very common and usually have other, milder causes. Cancer Research UK states plainly that most people with such symptoms do not have mouth or throat cancer; the point is for a change that does not go away to be looked at by a dentist or doctor.

• A mouth ulcer that has not healed for more than 3 weeks.
• A white, red or red and white patch on the lining of the mouth.
• A lump or thickening in the mouth, on the lip or on the neck.
• Numbness of the tongue or another part of the mouth, unusual bleeding.
• A loose tooth with no obvious cause, or swelling of the jaw that stops a denture from fitting.
• Pain or difficulty when swallowing, hoarseness that does not go away, weight loss without dieting.

Is every change in the mouth dangerous?

No. Most changes in the mouth have harmless causes: the NHS stresses that ulcers are rarely a sign of anything serious, usually result from biting the cheek, a poorly fitting denture, braces, a rough filling or a sharp edge of a tooth, and heal on their own within 1 to 2 weeks. Aphthous ulcers and their treatment are described in a separate article.

The threshold after which a change should be shown to a dentist or doctor is about 3 weeks. NICE recommends urgent investigation for an unexplained mouth ulcer lasting more than 3 weeks, and urgent assessment by a dentist for a lump on the lip or in the mouth and for a red or red and white patch.

What increases the risk of mouth cancer?

The Polish National Cancer Registry (Krajowy Rejestr Nowotworów) lists as risk factors for cancers of the lip, oral cavity and pharynx irritation of the lining of the mouth by tobacco smoke and strong alcohol, infection with human papillomavirus (HPV), sun exposure in the case of the lip, chronic irritation from poorly fitting dentures or chipped teeth, and a diet low in vegetables and fruit.

The NIDCR adds that most cancers of the oropharynx are linked to HPV infection, and that the risk rises with age, especially after 40. The NHS also lists chewing tobacco, a previous cancer, a weakened immune system and leukoplakia. The effect of smoking and other nicotine products on the teeth and gums is described in a separate article.

A risk factor does not mean disease, and having no risk factors is no reason not to show a change that does not go away. A change that has not healed for 3 weeks is worth showing to a dentist even if you do not smoke or drink alcohol.

How many people in Poland develop cancers of the mouth?

According to the Polish National Cancer Registry, 4,482 malignant cancers of the lip, oral cavity and pharynx were diagnosed in Poland in 2023, 3,147 in men and 1,335 in women, and 3,090 people died of them. They accounted for 3.2% of all malignant cancers diagnosed in men and 1.4% of those in women.

This figure covers the lip, oral cavity and pharynx together, because that is how the registry groups them; the fact sheet does not give a separate figure for the oral cavity alone. These cancers were diagnosed in more than twice as many men as women.

Leukoplakia, erythroplakia and lichen planus: what are precancerous changes?

Potentially malignant disorders, commonly called precancerous changes, are conditions of the lining of the mouth that increase the risk of cancer of the lip or oral cavity. Their list was updated in 2020 by experts from a World Health Organization (WHO) collaborating centre; it includes, among others, leukoplakia, erythroplakia, proliferative verrucous leukoplakia and oral lichen planus.

Leukoplakia is a white patch or patches in the mouth, while lichen planus usually causes white changes on the gums, tongue or cheeks, sometimes with burning when eating; lichen planus is not contagious. Erythroplakia is a red patch on the lining of the mouth, and NICE recommends that a red or red and white patch be assessed urgently by a dentist.

A review of 92 studies reports that 7.9% of such changes in total turned into cancer: 1.4% for lichen planus, 9.5% for leukoplakia and 33.1% for erythroplakia (Iocca et al., 2020). This means that in the studies most cases of leukoplakia and lichen planus did not turn into cancer, and the NHS recommends regular check-ups for leukoplakia even when treatment is not needed.

What does a dentist do on seeing a worrying change?

An examination of the mouth at the dentist covers more than the teeth. UK guidance for dental teams provides for looking at and feeling the mouth and the face and neck area at every check-up, and the NIDCR describes the dentist examining the face, neck, lips, the inside of the mouth and the back of the throat.

Cochrane reviews found insufficient evidence to recommend mass screening of the whole population, but stress that dentists should remain vigilant. The sensitivity of an ordinary examination by sight and touch ranged in these studies from 50 to 99%, with low certainty of evidence.

When a change raises doubts, the dentist refers the patient for further investigation, including a biopsy. The NHS describes a biopsy as taking a small piece of tissue from the affected area for examination; only the assessment of this tissue under a microscope, that is, histopathological examination, can tell a benign change from cancer.

The DiLO card: who issues it and what does it give you?

The oncology diagnosis and treatment card (karta DiLO) allows a patient to go through cancer diagnosis and treatment on the NFZ, Poland’s National Health Fund, without separate referrals. Under the act on the National Oncology Network, as in force from 11 August 2026, the card is issued by a primary care doctor, a doctor providing outpatient specialist care, or a doctor in a hospital or in a health programme (legal position as of 18 October 2026).

Dental treatment is a separate type of service under the act on publicly funded healthcare services and does not appear in this list, which is why a dentist who suspects cancer refers the patient on, for example to a family doctor or to a specialist outpatient clinic. No referral is needed to see an oncologist on the NFZ, and the NFZ stresses that a doctor in a private practice without a contract with the Fund cannot issue the card.

The act provides that the card is an electronic document, and that under the existing rules, including in paper form, it can be issued until 31 December 2026; the NFZ announces a full switch to e-DiLO from January 2027. According to the NFZ, the first visit to a specialist after the card is issued should take place within 14 days, and diagnosis should not take longer than 7 weeks.

How it works at DentalBlue

At DentalBlue in Białystok, a change in the mouth that does not heal or raises doubts is assessed by a dentist during a visit without pain, which includes a panoramic X-ray, a consultation, an examination and a written treatment plan; in the clinic’s price list it costs 300 zł, and “Badanie stomatologiczne” (dental examination) alone 200 zł. The price list also includes “Usunięcie zmiany na błonie śluzowej” (removal of a mucosal lesion, 500 zł) and “Badanie histopatologiczne” (histopathological examination, 100 zł). Surgical procedures are performed under local anaesthesia or, for qualified patients, under general anaesthesia. The dentist sets the final scope and cost, and prices may change. Cancer treatment is provided by specialist centres, which are reached by the pathway described above.