Source: Elsevier Global Medical News

Late oral effects of head and neck cancer therapy are “multiple, underreported, and under-appreciated. “That is the perspective of Joel Epstein, D.M.D., who has worked extensively with head and neck cancer patients experiencing severe dental and other oral problems following radiation therapy.

“The acute complications of head and neck cancer therapy are pretty well known, but the late complications are underappreciated,” Dr.  Epstein, director of oral medicine at City of Hope National Medical Center, Duarte, Calif., told attendees at the symposium. As head and neck cancer treatments have advanced and patients are living longer, the spectrum of treatment complications has shifted, he explained. In a 5-year, prospective longitudinal study of 122 patients with oral carcinoma, dry mouth, sticky saliva, speech changes, dental problems, and sleep disturbance were reported by all patients except those treated only with surgery. These complications persisted at 1 and 5 years and affected quality of life (Head Neck 2008;30:461-70).

According to Dr. Epstein, the data illustrate the need for better collaboration between oncologists and dentists. “While people discuss  the concept of multidisciplinary [and] interdisciplinary teams for the benefit of our patients, it is unfortunate that dentistry developed  separately from physicians and surgeons. So while we need to interact, we’re not really well prepared to do so, particularly in the  community,” he said.

Clinically, it’s important to evaluate oral care, including brushing, flossing, fluoride, and tobacco abstinence, at all head and neck cancer treatment follow-up visits. Patients should be assessed for xerostomia, speech, swallowing, mucosal sensitivity, and taste. Head and neck and oral exams should include assessments for saliva (wet mucosa), exposed bone, infection, and new lesions or recurrent cancer, and a dental exam (for plaque, caries, and periodontal health), Dr. Epstein recommended.

Dry mouth, in particular, can lead to a host of other chronic problems related to swallowing, eating, sleeping, and dental health. When the 50-item Vanderbilt Head and Neck Symptom Survey was administered to a total of 70 patients, 67 reported having dry mouth at more than 6 months’ follow up (Head Neck 2011 Aug. 24 [doi:10.1002/hed.21816]).

The majority reported that dry mouth makes chewing/swallowing difficult (65) and that it affects their ability to sleep (67) and  talk (64). With regard to eating and swallowing, similar majorities reported trouble eating solids (67) and drinking liquids (68), with food getting stuck in their mouth (66) and throat (67).

And, of concern, the same numbers of patients reported the sensation of choking or strangling on solids (66) and liquids (68). “The impact on function from the lack of saliva and the change in quality of saliva are issues we need to be more ready and willing to address,”  Dr. Epstein commented.

Taste and smell may also be profoundly altered. In the Vanderbilt survey, most patients reported altered taste (68), a decreased desire to eat (68), altered food choices (66), and a decrease in food eaten (66). A change in sense of smell was reported by 69 patients.

Such alterations often result in changes in diet, including decreased consumption of high-fiber food and of vitamins and other nutrients,  along with increased consumption of fats, caffeine, and sugar. All of these factors increase the risk for dietary deficiencies, as well as  dental caries.

Yet, altered taste sensation is not something patients might think to mention. “Half of patients experience altered taste sensation. But if  they think you’re not interested or you don’t ask, you may not know,”  Dr. Epstein commented.

Periodontal health is often compromised by hyposalivation, which can lead to inflammation, bone/attachment loss, oral infection, and necrosis. Dental demineralization and cavitation may develop as early as 2-3 months after cancer treatment and progress rapidly, leading to fractures of the gum line, tooth loss, and necrosis.

Demineralization appears as a change to white, which may not be recognized as a problem because of the belief that white teeth are  healthy. However, recognition at this stage is critical in order to prevent further dental damage, he said.

“The white change near the gum line and the tips of the teeth represent demineralization, and [in] time reversal can be accomplished  prior to structural breakdown. Once cavitation has occurred, fillings are needed and prevention must be instituted or the cavities will  recur and progress,” Dr. Epstein said in an interview.

In the Vanderbilt survey, reported dental problems included difficulty chewing because of teeth/dentures (54 of the 70 patients); tooth  sensitivity to hot, cold, or sweet foods (52); teeth feeling looser (51); teeth cracking/chipping (50); and trouble with dentures (24).

Oral candidiasis is another common problem, affecting approximately 39% of head and neck cancer patients during treatment and 33% afterward. One common clinical mistake is prescribing these patients antifungals that contain sugar, such as nystatin. “Nystatin is very high in sugar, and one of the [most commonly] used antifungals. The message is to avoid sugar-sweetened products in dry mouth patients and utilize alternatives,” Dr. Epstein said in the interview.

Mucosal sensitivity and pain is also frequent. In a meta-analysis of 22 studies published between 1990 and 2008, the prevalence of trismus was 25.4% in patients who received conventional radiotherapy and 5% for the few intensity-modulated radiation therapy studies that were included, suggesting that the newer radiation modality might diminish the problem (Support. Care Cancer 2010;18:1033-8).

Data suggest that the radiation effect on mandibular movement correlates with the radiation dose to the mastication muscles, with a  steep dose-response curve. Onset is typically 2-6 months post treatment and is ongoing. Concurrent chemotherapy may increase the  incidence and/or severity of mandibular immobility (Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 1999;88:365-73).

In the Vanderbilt survey, most patients reported burning in the throat or mouth (69); sensitivity to hot, spicy, or acid food (67);  sensitivity to dryness (69); and changes in food intake because of mucosal sensitivity (67); most patients also reported that mucosal  sensitivity prevents tooth brushing (63). “Mucosal sensitivity is a quality of life issue,” Dr. Epstein said.

The Vanderbilt survey was particularly illuminating, Dr. Epstein commented. Studies that utilize claims data probably underrepresent  the problem of long-term oral complications because dental and medical insurance are separate and the data are not easily combined, he added.

“Late oral effects are best diagnosed [and] managed in a multidisciplinary team with close communication between medical and  dental providers. … We really need to come together.”

The Multinational Association of Supportive Care in Cancer is developing tools to improve communication between dentistry and  medicine. These could be available for beta testing as early as this fall.

Dr. Epstein said he had no relevant financial disclosures.

This news story was resourced by the Oral Cancer Foundation, and vetted for appropriateness and accuracy.

 

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