Lesions of the Mouth and Throat
A patient often does not recognize an oral health problem in its early stages. For this reason, visits to the dentist are necessary to prevent the escalation of all kinds of diseases of the mouth and teeth. This is especially true of mouth lesions, disturbances in the tissues of the oral cavity or throat, some of which can lead to serious health concerns, including cancers. Increasingly, during routine cleaning appointments or dental checkups, dental teams are examining the tongue, the mouth, and the oropharynx (back portion of the mouth and throat), looking for suspicious lesions in the mouth and neck areas. Sometimes the external area of the neck is palpitated, as well, to determine whether unexplained lumps are present. While oral and throat cancers may not seem to be dental problems, there are important reasons for the increasingly reliance on dentists for their early detection.
First, some professional surveillance, is necessary. Changes in the epithelium (skin surface) lining the mouth and throat indicate the presence of lesions, but such changes are often obscured from patient view. In most cases, a patient is not aware of any lesions before medical examination. Although lesions can occur on lips, gums, or buccal mucosa (cheek-lining membranes), dangerous lesions are more frequently found in less visible places: on the ventrum (underside) or lateral portions (sides) of the tongue, on the soft palate (roof) of the mouth, on the floor of the mouth, or at the back of the mouth or throat. Further, changes in the epithelium of the mouth are often subtle and confusing. Even after viewing a mouth lesion, a patient is unlikely to have the medical expertise necessary to rule out the many common, but harmless, forms of lesions that require no intervention, nor would he or she be likely to identify a dangerous lesion from its appearance.
Moreover, the reasons why dental teams are assuming the important function of identifying mouth lesions are practical ones. Though cancers of the head and neck may be referred by dentists to other members of the medical profession for treatment, dentists and their teams are far more likely to find cancerous and precancerous lesions initially. Whether a patient complains of mouth disturbance or not, dental professionals always view the interior of the mouth. A doctor seldom does so without patient complaint. Additionally, dentists are uniquely equipped to view the mouth and oropharyngeal areas, using the bright, well-directed lighting systems and optical aids of their discipline. As a general rule, too, dentists are seen more regularly and more often than are physicians, and this gives dental staff frequent opportunities to conduct examinations of oral and oropharyngeal tissues as adjuncts to dental surveys. Given the fact that lesions will sometimes prove to be life-threatening, it is easy to see why examinations of the entire oral cavity and oropharynx have increasingly been added to the responsibilities of dental teams.
Dental teams are also taking on the equally important work of educating patients about the need for regular, professional examinations of mouth and oropharyngeal areas. Obviously, most patients are not attuned to the idea that lesions in these areas exist, or that such lesions may signal the beginnings of serious problems. Additionally, there are misapprehensions. The word lesion may bring to mind soreness though early changes in the lining of the mouth and throat are often painless. This is true for patients despite the fact that most lesions seen are actually due to physical trauma, rather than mouth disease.
Recent research has suggested that between twelve and twenty-five percent in a group of general patients will exhibit oral lesions, usually unknowingly. Patients with dentures are disproportionately represented at a rate of two and a half times that of patients who do not wear dentures, suggesting that these lesions may originate in irritation from the dentures themselves. Smokers are almost twice as likely to display lesions. Many lesions are fairly innocuous. Lesions may are inherent and in no need of treatment. Others may be related to inflammation or infection and may or may not require treatment. Still others may be iatrogenic (drug-induced). However, a certain portion will be idiopathic, a point of origin for developing disease.
Typically precancerous or cancerous lesions are found in about one percent of patients. This smaller group of lesions is comprised of three general types and a host of anomalies. The most common form, representing about thirty-six percent of cancerous or potentially cancerous lesions, is known as leukoplakia. The condition is first seen as a patch or patches of white film which cannot be wiped away from the tissue of the tongue, mouth, or throat. A more dangerous form of cancerous or typically precancerous lesion, known as erythroplakia, appears in isolated, velvety, red patches. Though erythroplakia is less common than leukoplakia, accounting for only about seventeen percent of cancerous and potentially pre-cancerous lesions, it is far more likely than leukoplakia to be carcinoma (cancer), whether in situ (not yet having spread to levels of tissue beneath the epithelium), or already invasive of tissues beneath the epithelium. The third general type, known as erythroleukoplakia, appears as a patch or patches of mixed red and white areas. Its prognosis is also not a good one as such sites have a high incidence of carcinoma and of dysplasia (odd cells, sometimes in the process of becoming cancerous). Other suspicious lesions may present as ulcerations, unusually pigmented tissue, or tissue enlargements. As a general rule, redness and larger patches are more highly associated with carcinoma. Because it is not possible to be sure which lesions will go on to produce cancer, however, all of the lesions in this suspicious one percent should be fully evaluated in a clinical setting.
If your dentist or hygienist notices a lesion that he or she does not recognize as harmless, several procedures may be initiated. The simplest is that your lesions will be placed under observation for a period of perhaps three weeks. This may allow healing from trauma, infection, and inflammation. Photos might be taken of the lesions in support of a period of observation, or your dental professional might simply request that you return so that the spot or spots can be regularly monitored visually. Many lesions resolve themselves over time or when irritants, such as smoking or ill-fitting dentures, are eliminated. If the lesion is regarded initially as more suspicious, or if it persists, the dental team might use a tissue dye to identify the cellular changes which have occurred at the site. Dyes such as toluidine blue are reliable in their characteristic staining of cancerous tissue. Dental fluorescence is also sometimes used as an adjunct to diagnosis of suspicious lesions. Both dyeing and fluorescence show consistency in identifying cancerous mouth and throat tissues. However, in cases where dysplasia or cancer is suspected, a dental team will generally take a biopsy, a sample of the tissue for examination under a microscope, or will refer the patient to another office or laboratory where a biopsy can be performed. Biopsy, with examination of questionable tissue by a pathologist, is the only way cancerous and precancerous cells can be reliably and completely evaluated for treatment.
Most biopsies test negative for cancer, and no treatment is necessary, aside from regular dental surveillance. Some cells tested will exhibit mild dysplasia, which may resolve itself through dietary or lifestyle changes such as quitting smoking or reducing alcohol consumption. Other cell samples will exhibit the more serious changes of cancer cells in situ or even of cancer cells invasive of other tissues. In these latter two situations, the patient will most likely be referred to specialists in cancer treatments. For most regular dental patients, however, these treatments will represent early intervention. At this stage, even oral and oropharyngeal cancer can be treated quite successfully.
Sometimes, also, the first identified signs of infection by human immunodeficiency virus (HIV) are gum lesions seen by a dentist. In these cases, the value to patients is early referral to specialists and, hopefully, timely intervention in the disease.
No matter what the diagnosis, however, there is no doubt that earlier intervention does vastly improve outcomes for the diseases detected through mouth and throat inspection. Recently, too, a new factor has emerged suggesting a need for higher public profiling of mouth and throat lesions. Though it might be expected that oral and oropharyngeal cancers would be decreasing because of the decline in smoking rates over the past few decades, recent reports indicate that the incidence of oral and oropharyngeal cancer is actually rising rapidly. Moreover, the demographic of these cancers is changing. Mouth and throat cancers have historically been linked overwhelmingly to age and the habits of smoking and drinking. While most new cases are still found in males over fifty who smoke and/or drink, there are increasing numbers of new cases being found in younger individuals, some of whom do not even smoke.
Substantial evidence now links this new rise in the rate of oral and oropharyngeal cancers to the sexually transmitted human papilloma virus (HPV), especially for males engaging in oral sex with HPV-positive female partners. HPV is a common virus, estimated to infect up to eighty percent of sexually active people in Canada. In one of its forms, HPV-16, it appears to be instrumental in causing as many as two-thirds of the cases of current Canadian oral and oropharyngeal cancers. Clearly it is wise to be on the watch for early lesions as signs of the damages caused by such a pervasive and incurable virus.
Patients should also be aware of certain other symptoms which may be present in the mouth and throat or in the body as a whole. Early cancers in the neck may be difficult to see, even for a dental team, and any voice change, persistent cough, difficulty swallowing, unusual soreness of the throat, or weight loss should be reported during mouth and neck examinations. Other signs a patient should report would be sensitivity or a feeling of roughness on epithelial surfaces of the mouth. Once again, patients may find that consultation with their dental team offers the most convenient route to examination and early treatment.
Finally, though the rise of HPV-induced oral and oropharyngeal cancers is not good news, there is some cause for optimism with such cancers. While infection with the HPV virus is incurable at present, treatments of oral and oropharyngeal cancers attributed to HPV have better outcomes for patients than do treatments given in mouth and throat cancers whose causes are firmly linked to age, drinking, and smoking. HPV-linked oral and oropharyngeal cancers are proving amenable to less harsh forms of cancer treatment and result in sixty percent fewer deaths than do mouth and throat cancers of more traditional origins. Certainly, the promise of an early detection of dangerous lesions, coupled with better outcomes, provides more reason than ever for dental patients to make time to attend those regular dental cleanings and checkups.