What is mouth cancer?

Mouth cancer — also called oral cancer, or cancer of the oral cavity — describes a family of cancers arising in the mouth. The most commonly affected sites are the lips, the floor of the mouth, and parts of the tongue, particularly the sides and underside. Less commonly it arises in the cheeks, gums, roof of the mouth, and the palate and tonsil area.

The single most useful thing to take from this page: any ulcer, lump, or red or white patch in the mouth that has not resolved in two to three weeks should be examined. Early oral cancer is very often painless, which is exactly why it gets ignored. Do not wait for it to hurt.

This is general information. If you have a symptom that concerns you, see a dentist or doctor — do not attempt to self-assess from an article. Oral cancer: signs, risk factors and how your dentist can help and how your dentist helps with early detection cover the same subject from the patient’s side.

Risk factors

The major, well-established risk factors are:

Smoking and other tobacco use, including smokeless tobacco — the largest single factor
Excessive alcohol consumption. Tobacco and alcohol together multiply risk rather than simply adding it. What impact does wine have on my teeth? and six foods to avoid for healthy teeth touch on the same point from the dental side
Excessive sun exposure, specifically for lip cancer
Areca nut / betel nut use, including paan and gutka preparations — a major risk factor in some communities and independent of tobacco
Human papillomavirus (HPV), particularly HPV-16, which is increasingly associated with cancers of the oropharynx, tonsil and base of tongue — including in people who have never smoked
Family history of oral cancer
Epstein-Barr virus (EBV), associated with nasopharyngeal cancer
Increasing age, and being male — though the HPV-associated group skews younger. I am in my late 60s — how can I keep my teeth in top condition?
A previous head and neck cancer
Immunosuppression

On vaping: the honest answer is that nobody knows yet. E-cigarettes have not been in use for anything like the time it took to establish the tobacco link, so there is no reliable long-term cancer evidence either way — an absence of evidence, not evidence of absence. The shorter-term oral effects are better characterised and are not trivial: see the effects of vaping on your oral health and are e-cigarettes bad for my teeth?

One clarification worth making to a claim that circulates widely: poor oral hygiene and gum disease are not established causes of oral cancer. There is an observed association, but it is substantially confounded by the fact that people who smoke and drink heavily also tend to have poorer oral health. Good oral hygiene is worth maintaining for many reasons — what is the ideal daily routine for oral hygiene?, is flossing really that important?, when do you need deeper cleaning? and what is gum disease? — but preventing cancer is not a claim the evidence supports. The same care is warranted with the other “mouth and body” claims: health problems linked to poor oral hygiene and dental health and general wellbeing describe associations of varying strength, of which diabetes and periodontal disease is the best evidenced.

What does reduce risk, on the evidence: stopping smoking, reducing alcohol, avoiding betel nut, using sun protection on the lips, and HPV vaccination, which in Australia is available through the national immunisation programme.

Symptoms

See a dentist or doctor if you have any of the following:

Recurrent or non-healing ulcers — particularly any ulcer lasting beyond two to three weeks. The cause of mouth ulcers and their usual treatments covers the ordinary kind
A persistent lump in the head or neck region
Pain or difficulty with normal function — eating, speaking, or swallowing
Unexplained bleeding or numbness in the mouth — bleeding gums has far more common explanations
Loose teeth without an obvious dental cause — usually periodontal disease
Unexplained swellings
White or red patches anywhere in the mouth — distinct from marks on the teeth themselves, which are covered in what causes white spots on teeth?
Unexplained weight loss

Additional signs worth knowing: a persistent sore throat or hoarseness, the sensation of something caught in the throat, difficulty moving the jaw or tongue — more often a jaw joint problem — and a denture that has suddenly stopped fitting.

Most of these symptoms turn out to have benign causes — trauma ulcers, infections, denture rubbing. The point is not to alarm, but to make clear that persistence is the feature that matters. A painful ulcer that resolves in ten days is almost never a concern. A painless one that is still there at four weeks needs looking at.

Diagnosis

Oral cancer can begin and grow with minimal warning. Signs are frequently detected by a dentist during a routine examination — which is a large part of why regular check-ups and cleans matter. See how often should I go to the dentist?, dental cleans with our hygienists and understanding your treatment.

At those appointments you will notice your dentist examining the soft tissues: tongue (including the sides and underside), cheeks, lips, gums, floor of the mouth, and palate. They may also feel the neck for lymph nodes. It takes a minute or two, and for most adults it is the only oral cancer screening they receive. Seeing the same practice over time is what makes it work, because change is easier to spot than abnormality — is it important to have a family dentist?

If an abnormality is suspected, your dentist will refer you — usually to an oral medicine specialist, oral and maxillofacial surgeon, or ENT surgeon — for further investigation. Why would I need to see a dental specialist? and dentists and registered specialists explain how that referral works.

Investigation	Purpose
Biopsy	A tissue sample examined under a microscope. This is what establishes a definitive diagnosis — nothing else does
Radiographs	Assessment of the hard tissues — see how safe are dental x-rays?
Endoscopy	Direct examination of the nose, sinuses, larynx and pharynx
Scans (PET, CT, MRI)	Determining the location and any spread

A referral for investigation is not a diagnosis. Most lesions biopsied turn out to be benign.

Treatment

Where oral cancer is confirmed, treatment depends on the stage and grade of the disease. It commonly involves a combination of surgery, radiation therapy and chemotherapy, with a full multidisciplinary team of health professionals involved in each case — surgeons, oncologists, radiation oncologists, pathologists, speech pathologists, dietitians, and dental specialists. Complex dental cases: what happens when multiple specialists collaborate describes how that kind of coordination works on the dental side.

Dentistry has a specific role before and after cancer treatment that is worth knowing about:

Before radiotherapy to the head and neck, a dental assessment is important. Teeth with a poor prognosis are usually treated or removed beforehand, because extractions from irradiated bone carry a risk of osteoradionecrosis.
During and after treatment, radiotherapy and some chemotherapy cause severe dry mouth, mucositis and a sharply elevated decay risk. High-fluoride products, frequent recall and close monitoring become essential. See my mouth is always dry — does it affect my teeth?, my mouth always feels dry! What can I do?, the benefits of fluoride and selecting a toothpaste: fluoride or non-fluoride?

Stage at diagnosis is the strongest predictor of outcome. Cancers found early, while small and localised, are treated far more successfully and with less disfiguring surgery than those found late. That is the entire case for having a persistent ulcer looked at rather than waiting.

Common questions

How common is mouth cancer in Australia? Should I actually be worried?

It is uncommon, and it is not rare. Both halves of that sentence matter.

The national picture, from Dental Health Services Victoria: there are more than 4,000 new cases of head, neck and lip cancers diagnosed in Australia every year, the majority of them oral cancers, and in 2022 there were an estimated 2,642 cases of lip and oral cancers — a figure DHSV expects to rise.

The Victorian picture, from the Victorian Cancer Registry via Cancer Council Victoria, is more granular. Oral and oropharyngeal cancer is currently diagnosed at a rate of 23 per 100,000 males and 8 per 100,000 females. The median age at diagnosis is 64 in males and 67 in females. In 2023 it accounted for 3.1% of all cancers diagnosed and 2.6% of all cancer-related deaths in Victoria, making it the 6th most commonly diagnosed cancer and the 11th most common cause of cancer-related death in the state.

What to do with those numbers: they do not justify anxiety about every mouth ulcer, and they do justify the two minutes your dentist spends looking at your tongue, cheeks and the floor of your mouth. Sixth most commonly diagnosed is not a disease to dismiss.

Why does everyone insist on early detection? Does it really change the outcome?

Because the survival figure for this cancer is poor, and the reason it is poor is not mysterious. The Royal Australian College of General Practitioners, writing in Australian Journal of General Practice in December 2024, states it plainly: despite advances in diagnosis, treatment and management, oral cancer has "a relatively low five-year survival rate, at around 50%, mostly due to diagnostic delays."

That last clause is the one to hold onto. The problem being described is not that the treatments do not work; it is that the disease is too often found late.

There is a structural reason it is found late, and the same paper quantifies it. In 2021–22, almost 90% of Australians received at least one Medicare-subsidised service, while for 2020–21 only 48% of Australians had seen a dental professional in the past 12 months. Fewer than half of us are in front of the person whose routine examination includes looking at the soft tissues. That is why Dental Health Services Victoria and the RACGP built a national online learning resource to help GPs recognise suspicious lesions and refer them — because for many people the GP is the only clinician who will see the inside of their mouth in a given year.

The practical consequence for you is unglamorous: keep the check-up, and if a lesion has not gone in three weeks, do not wait for the next one.

I have never smoked and I barely drink. Does that rule me out?

No, and this is where the risk picture has genuinely shifted.

The RACGP paper flags two changes directly. The first is areca (betel) nut chewing — a practice common in parts of South Asia that is "a growing trend in Australia, coinciding with an increasing number of immigrants, which might affect the rate of oral cancer diagnosis in the future." It is a risk factor in its own right, independent of tobacco, and it is often not mentioned at a dental appointment because people do not think of it as relevant.

The second is more unexpected: the paper describes "an emerging subgroup of non-smoking and non-drinking middle-aged women with tongue cancers" as concerning. The classic risk profile — older, male, smokes, drinks — no longer describes every case.

Add to that the HPV-associated cancers of the tonsil, oropharynx and base of tongue listed earlier on this page, which occur in people who have never smoked and skew younger, and the lip cancers driven by sun exposure, which are an occupational risk for anyone who works outdoors in Australia.

None of that means a never-smoker should worry about every ulcer. It means the answer to "am I the type of person who gets this?" is not reliable enough to act on, and the three-week rule applies to everyone.

I mentioned something in my mouth and was told not to worry. What should I do?

Ask for it to be dated, described and reviewed — and hold the review date yourself.

The practical version of that conversation:

"Can you note in my record what you are seeing, where it is and how big it is today?" A described and measured lesion can be compared at the next visit. An undocumented one cannot.
"When should it be gone by, and what should I do if it is not?" This turns reassurance into a plan with a date attached. Three weeks is the usual threshold for a lesion that is not resolving.
"If it is still there then, what would the next step be?" The answer should involve referral, because a biopsy is the only thing that establishes a diagnosis — nothing on this page or any other substitutes for it.

If a lesion persists past the agreed date, go back rather than waiting for the next routine appointment, and say that it has not resolved. If you remain concerned after that, seeking another opinion is a reasonable thing to do and not a discourtesy — see second opinions and corrective dentistry. Diagnostic delay is the documented reason this cancer's survival figures look the way they do, and part of that delay sits with the patient who decided not to make a fuss.

For support and information about cancer generally, Cancer Council 13 11 20.

Practical details

If you have a symptom described here, make an appointment. If you have a lesion that has persisted beyond three weeks, do so promptly — contact us.

Oral medicine and oral and maxillofacial surgery are recognised dental specialties. Specialist registration can be verified on the AHPRA register, or by calling 1300 419 495. The clinical team is listed by name.

Incidence and survival figures quoted above are from Cancer Council Victoria and the Victorian Cancer Registry, Dental Health Services Victoria, and the Australian Journal of General Practice (RACGP, December 2024). Those publications remain the primary sources, and figures are revised periodically.

For information and support relating to cancer, Cancer Council 13 11 20. To stop smoking, Quitline 13 7848.

Smile Solutions, Level 1, 220 Collins Street, Manchester Unity Building, Melbourne VIC 3000 — getting here. Phone 13 13 96, or theteam@smilesolutions.com.au. Monday–Friday 8.00am–6.00pm, Saturday 8.30am–1.30pm, Sunday by appointment. Fee ranges are in the price guide.

Published 14 October 2020, by Dr Avi Aggarwal. General information only; it does not replace advice from your treating practitioner. It is not a diagnostic tool and should not be used to self-assess a symptom. Figures quoted describe populations, not individuals.

Smile Solutions trades under ABN 28 193 514 103.