WATCH YOUR MOUTH

ORAL CANCER is one of the country’s biggest killers. We look at the best detection techniques.

By Dr Lara M DeAngelis (Oral Medicine Registrar) and Professor Michael J McCullough (Oral Medicine Specialist)

Every week in Victoria alone, more than 14 people are diagnosed with these types of cancers and five people die from them. Despite declining rates of smoking and advances in treatment, the number of non-smoking oral cancer patients is increasing, and the five-year survival rate remains at only 66%.

One of the key factors leading to low survival rates is that cancer of the lips, oral cavity or salivary glands is commonly diagnosed at a late stage. By that time, these cancers are already advanced and have spread into adjacent tissue and local lymph nodes. Most early stage oral cancer is painless, presenting as innocuous lesions that are difficult to recognise during limited examination.

It is not possible to predict if, or when, there will be a malignant change in a pre-existing oral lesion. These lesions are relatively common, occurring in around two per cent of the population and often appear as flat white areas in the mouth, termed ‘leukoplakia’. The presence of dysplasia observed histopathologically in biopsies of tissue remains the best predictor for developing oral cancer. However, the grade of dysplasia does not always correlate with the potential for malignant transformation.

Risk factors

Modifiable risk factors play a major causative role in oral cancer pathogenesis. The greatest risk factor for oral cancer continues to be tobacco use, which results in a tenfold increase in risk when compared to non-smokers. Regular alcohol consumption greater than three standard drinks per day also increases risk by threefold. The combination of these two risk factors is greater than either one in isolation, and approximately 75% of all oral cancers are associated with consumption of tobacco and alcohol. Other risk factors for oral cancer include regular use of betel nut, paan, snuff and smokeless tobacco. Rising age (over 50 – 60 years), being immunocompromised, and a history of a previous oral squamous cell carcinoma are important risk factors for oral cancer.

Prolonged exposure to the sun without proper protection is a significant risk factor for lip cancer. Viruses, in particular the human papillomavirus (HPV) subtypes 16 and 18, have been strongly linked to oropharyngeal cancer with an increasing number of these cancers occurring over the past 10 years. However, HPV is involved in only a small number of oral cavity cancers; around two per cent. While it has been postulated that genetic predisposition may increase susceptibility to oral cancer, no specific genetic component has been clearly established as a risk factor. Hence, in many instances the risk factors for oral cancer are modifiable.

Signs and symptoms

Oral cancer can present in a variety of ways and in any area of the oral cavity. The most obvious clinical presentations of oral cancer are a non-healing ulcer or an exophytic, indurated swelling with or without fixation, as well as palpable neck lymph nodes. The most common sites for oral cancer are on the lateral margins of the tongue, the buccal mucosa (lining of the cheeks) and the floor of mouth. Less obvious clinical presentations include white, red, or mixed red and white patches that cannot be removed during clinical examination. In the early stages, most presentations of oral cancer are painless. In the later stages patients have pain, numbness or altered sensation, as well as difficulty swallowing, chewing or moving the tongue.

The most effective screening method dental practitioners can undertake is a thorough oral examination using good lighting to visually examine the entire oral mucosa. Any lesion that has persisted for more than two weeks without a definite cause should be referred for immediate biopsy. It should be recognised that the major cause for oral mucosal changes is trauma and such things as sharp cusps of teeth, broken fillings and ill-fitting dentures. These causes need treatment and should be reassessed for healing two weeks later. Failure to improve within two weeks requires referral for further management. >

Assessment

Any patients suspected of having oral cancer should be referred, by a dentist, to an oral medicine specialist or oral and maxillofacial surgeon for further assessment. Assessment includes a comprehensive oral examination involving extraoral examination and palpation of the lymph nodes in the head and neck region. A full intra-oral examination using white dental light is conducted. The need for adjunctive tests including blood tests, selective imaging, use of diagnostic aids, cytology and histopathological assessment will be determined at the clinician’s discretion at the time of examination. For definitive diagnosis, histopathological assessment of biopsy material is required.

Management

Definitive diagnosis of oral cancer necessitates referral to a tertiary hospital for multidisciplinary treatment planning and management. In the first instance, the patient would undergo extensive imaging including CT, MRI and often ultrasound examination so that accurate staging can occur to guide treatment. Multidisciplinary management usually consists of multiple treatment modalities including a combination of surgery, radiotherapy and/or chemotherapy. The team involved in managing a patient with oral cancer usually consists of oral and maxillofacial, plastic, ENT, and head and neck surgeons, radiation oncologists, speech pathologists, radiologists, dieticians and other dental specialists. The best management outcome for the patient is surgical eradication of the cancer at an early stage. For Aboriginal and Torres Strait Islander patients, it is fitting to involve a culturally appropriate healthcare professional in that person’s treatment.

Prevention and early detection

Counselling by healthcare professionals is key to reducing risk factors, particularly smoking and drinking alcohol. Anyone displaying oral mucosal changes, which have potential malignant change, should be reviewed regularly; either by an oral medicine specialist or an oral and maxillofacial surgeon. Self-monitoring for changes in appearance and consistency of a lesion between review appointments should also be encouraged so that patients can represent earlier if they are concerned. Support of patients at greater risk by their healthcare team, as well as a patients’ ability to change modifiable factors, can play an important role in avoiding adverse outcomes.

This article was first published in the Australian Medical Association Victoria VicDoc magazine

Six ways to improve your oral examination

By Dr Amanda Phoon Nguyen, Oral Medicine Specialist

Tissue changes involving the floor of the mouth

Tissue changes involving the right buccal mucosa and lateral tongue

Loss of definition of the vermilion border and crusting involving lower lip

ORAL CANCER IS a significant health burden and is recognised as the sixth most common cancer, worldwide. In Australia, oral cancer accounts for about 2-3 per cent of all cancers. A declining trend of the incidence of lip and oral cavity cancer, and a rise in the incidence of oropharyngeal cancer has been reported. However, despite advances in treatment and management options, survival rates have not dramatically improved in the last few decades. Overall survival rates for oral cancer are poor, at about 50 per cent for all anatomical sites and stages.

When looking at studies, the use of the term “oral cancer” can sometimes be confusing. Oral cancers are a heterogeneous group of conditions encompassing the main subsites of the external lip, oral cavity and oropharynx.

When reading articles it’s important to consider which specific subsite the paper refers to, as the aetiology, management and prognosis of lip cancer, oral cavity cancer and oropharyngeal cancer can be different.

Improve your evaluation

Early detection of potentially malignant disease has been proven to improve the clinical outcome for patients, and therefore it is very important to perform thorough intra and extraoral examinations for every patient.

Here are six ways to improve the patient risk evaluation and conventional visual screening of oral tissues?

1 TAKE A GOOD HISTORY

It is important to take a good history and note any factors that may put the patient at a higher risk of oral cancer. This may include a current habit or a history of smoking, alcohol consumption, use of smokeless tobacco, use of a mouthwash containing alcohol, or a family or personal history of cancer.

2 BE AWARE OF ANY SUSPICIOUS CHANGES

Changes to the oral mucosa are detected visually due to light interaction with tissue. As the tissue changes, there are colour alterations that we can see. The most common signs are white and red changes to the mucosa. Changes can appear as an ulcerative, flat, raised or exophytic, red and/or white lesions.

The oral cavity can also be the site of cancer metastasis from other parts of the body, most commonly of breast, kidney and lung. Signs such as firmness to palpation, pain and ulceration are more commonly seen when the lesion is already malignant. The poor prognosis of oral cancer can largely be attributed to its frequent diagnosis at an advanced stage, and early detection is key. Early lesions are usually asymptomatic.

3 USE APPROPRIATE LIGHTING

Examination with the naked eye should be done under white light where possible (projected incandescent or halogen illumination). The use of loupes and/or an LED headlight, where available, will assist with the examination.

Actinic cheilitis, also termed actinic cheilosis, actinic keratosis of the lip, solar cheilosis, sailor’s lip, and farmer’s lip, is a type of lip inflammation caused by longterm sunlight exposure. The prolonged solar exposure produces irreversible damage to the lower lip, and this is very common in Australia.

It is a premalignant condition that could develop into squamous cell carcinoma. Signs include the loss definition of the vermilion border and mucosal changes to the lips, such as dry or mottled skin, white or grey plaques or patches, and crusting. Persistent ulceration, crusting or firmness to palpation should be viewed with suspicion.

4 Check the tissues in a systematic manner

The development of a consistent examination sequence is important. While the actual order of this does not matter, all elements must be completed. Before looking in the mouth, a thorough extraoral examination should not be missed. This should include a general examination of the patient and inspection of the temporomandibular joints, facial skin, lymph nodes, neck, midline neck structures, plus lip and perioral structures. By doing the same sequence for all patients, clinicians are more likely to consistently check all sites.

High risk sites for oral cavity squamous cell carcinoma includes the lateral and ventral tongue, and floor of mouth. Other areas that are frequently missed include the soft palate, posterior lateral tongue and oropharynx.

5 PALPATE AS WELL AS VISUALLY INSPECT STRUCTURES

Besides looking at structures, it is also important to palpate them. Two worrying signs are induration and fixation. Induration is where there is an increase in the tissue density (the tissue becomes hard), and fixation is loss of tissue mobility, where the tissue does not move. Cancer can cause tissues to become indurated and fixed.

6 REFER OR REVIEW

Most oral mucosal lesions of traumatic aetiology will resolve within two weeks, once the cause is removed. A common scenario is a chipped tooth causing tissue changes (such as a white patch) of the adjacent mucosa. The tissue should return to a normal appearance once the tooth is smoothed, and this should be ascertained with a review after two weeks.

Good recall systems should be in place to ensure the patient returns for the review and the appointment is not missed. Any oral mucosal lesion that persists beyond a two-week period should be viewed with a degree of suspicion. This patient should be referred directly to the appropriate practitioner, such as an oral medicine specialist. •