:) smile-on - Articles

CPD Record | Add a Course

Email

Password

Each week, smile-on updates our online journal of articles on the latest developments in the dental sphere - clinical, techniques, patient and practice management and IT developments. Browse our extensive archive using the keyword or category search boxes, below.



	in category: Email this article to a friend Print version

Supportive Oral Care in Cancer Patients
Monique A. Stokman & Fred K.L. Spijkervet from the University Medical Center Groningen in The Netherlands discuss the effects of chemotherapy on the function of the mouth and the importance of supportive oral care.

Radiation of head and neck malignancies and the effects of chemotherapy in cancer patients may disturb the normal integrity and function of the mouth. This can lead to mucosal changes (mucositis), bleeding, infections (bacterial, fungal and/or viral), salivary gland dysfunction (xerostomia), dental decay, and periodontal diseases. Supportive oral care is mandatory before, during and after oncology treatment.^1,2

The importance of supportive oral care in cancer patients lies in the prevention/treatment of acute and late sequelae, the effect on the nutritional status, and health related quality of life. Every oncology center should have a patient management protocol in which early referral of patients for oral evaluation is outlined, and in which the role of the dental hygienist is clear.

Before onset of the oncology treatment, all patients need a comprehensive dental evaluation and treatment of foci of infection.³ The targets of the pre-treatment evaluation are identification of risk factors for the development of oral side-effects that may interfere with the cancer treatment. Secondly, the dental treatment, which is necessary to eliminate foci of infections, or needed prophylaxis are performed and a comprehensive oral care program is initiated. The dental hygienist evaluates the periodontal condition, level of oral hygiene and the patient’s motivation for self-care. Together with the oral maxillofacial surgeon and the hospital dentist a dental/oral treatment plan is outlined for each individual patient.

A couple of dilemmas in determining risk factors can be mentioned:

1) A focus of infection has a different impact that is related to the type of disease. For example, a radiation patient needs to be free of foci in the long term because of the risk of the development of osteoradionecrosis (ORN). In contrast, for the chemotherapy patient, this life long free of foci is not mandatory after the oncology treatment.

2) The time frame needed before cancer treatment starts is important. For radiation patients, the time frame should be 10–14 days free of foci before the start of radiotherapy. For chemotherapy patients, the treatment of foci is dependent on the expected level and duration of neutropenia.

A distinction can be made between acute and late sequelae. By definition, late effects are reactions that develop or still exist 3 months after cessation of the cancer treatment. Acute sequelae are: mucositis, loss of taste, oral infections, and xerostomia. Late reactions are xerostomia, trismus, radiation caries, osteoradionecrosis, and tooth development deformation.

Mucositis
This acute toxicity can develop in both radiation and cytotoxic regimens. Mucositis is defined as an injury of the oral mucosa due to radiation and/or chemotherapy. It is clinically seen as erythema followed by pseudomembranous ulceration of the oral mucosa. Mucositis is a unpleasant, common and sometimes unbearable toxicity. It often has negative effects on the nutritional status of the patient. The painful lesions significantly affect the patient’s well being and can be dose-limiting. In a survey of bone marrow transplantation patients, 42 percent of the patients reported mouth sores as the most troubling side effect Also, in a survey of head and neck radiation patients, 38 percent of the patients reported throat and mouth sores with pain as the most troubling side effect.⁵

Historically, mucositis was thought to arise as a consequence of epithelial injury. It was hypothesised that radiotherapy and chemotherapy targeted rapidly proliferating cells at the basal layer, causing the loss of the ability of the tissue to renew itself. Nowadays mucositis is recognized as an epithelial and subepithelial injury that develops in five phases: (1) initiation; (2) primary damage response; (3) signal amplification; (4) ulceration; (5) healing.⁶

After reviewing the literature, the Multinational Association of Supportive Care in Cancer (MASCC) and the International Society for Oral Oncology (ISOO) created clinical practice guidelines for the prevention and treatment of cancer therapy-induced oral and gastrointestinal mucositis.⁷ There is not sufficient scientific evidence to provide a guideline for basic oral care and education, but its importance in maintaining mucosal health, integrity and function is generally accepted.

Recommendations for reduction of radiotherapy-induced mucositis include the use of benzydamine. However, this is not available in all countries. For prevention of chemotherapy-induced mucositis the only evidenced recommendation is the use of oral cryotherapy in patients receiving bolus 5-FU. Chlorhexidine is not recommended to prevent mucositis during radiotherapy and chemotherapy, and neither is the use of pentoxifylline in chemotherapy patients.

The approach used in our clinic for mucositis treatment consists of: optimal oral hygiene, salt-soda solution rinsing, daily professional cleansing, no denture wearing in edentulous or partially edentulous patients, and diet advice.

Rinsing/cleansing agents are recommended to reduce mucosal irritation, to remove debris and to moisture and lubricate the mucosa. It is recommended to rinse with a salt-soda solution at least 8–10 times a day during radiotherapy and 4–10 times a day during chemotherapy. Chlorhexidine rinses should be used for plaque control only when other mechanical techniques like toothbrushing are not possible anymore. To avoid irritation, a non-alcoholic chlorhexidine rinse is advised.

In our protocol, daily professional spraying of the mouth with saline is added for all head-neck radiation patients and, on indication, for the chemotherapy patient. For this purpose a Ritterspray is used. The spray cylinder is filled with sodiumchloride and connected to the pressured air system on the dental unit or on the nursery unit of the patient. The pressure is set so that the liquid will come out like a fine haze. The patients appreciate this daily supportive care and it motivates them to maintain good dental hygiene.

The use of dentures may cause excessive mucosal irritation that may aggravate mucosal pain and mucositis. Also, orthodontic appliances have to be removed before cancer treatment and patients must be discouraged from wearing partial or full dentures. An exception must be made for patients with resection prostheses and obturators that are needed for closure of the surgical defect and prevention of tissue reaction.

Oral Infections
In healthy individuals the development of oral infections is an exception because of the existence of an intact defense against colonization. The colonisation defense clears away bacteria entering the oral cavity with food, personal contacts, the fecal-oral route, etc. In patients with underlying disease, such as cancer, the colonization defense can be changed, which leads to colonization by yeasts and/or other infections. The result can be the development of candidosis. With radiation therapy the development of candidosis is less obvious than with chemotherapy, but if the supportive care fails during radiotherapy, candidosis will develop in about 10–20 percent of the cases. Development of herpetic infections during or after radiation is very rare. In contrast to cytotoxic treatment, herpetic infections or reactivation are seen in 40–50 percent of patients. The main symptoms of a candidosis are acute (within one day) burning sensation of the mucosa and/or the development of the typical white/yellow candida colonies at the mucosa.

Xerostomia
It is mentioned as late sequelae, but in fact it already develops from the first day of radiation. Also, it is a severe life long sequelae because it is always there, day and night—the feeling of a dried, rough mucosa. During radiation treatment there is a tremendous drop in salivary flow rate during the first week, which decreases in the first two weeks to about 90 percent of the initial flow rate. After a cumulative dose of 40 Gy, the decrease will be about 95 percent of the initial flow rate and this dosage level will provide irreversible damage to the salivary glands. This typical decrease in salivary flow rate follows a tight dose response relationship. In chemotherapy patients a clinical hyposalivation is only seen during therapy, but this hyposalivation is reversible. Prevention of xerostomia is one of the most important issues.

A lot of research is carried out in regards to the salivary function as it relates to radiation. Yet, prevention of xerostomia is still questionable. Prevention of xerostomia can only be achieved by modifying the treatment portals by excluding the salivary glands from the radiation portals, or the use of radioprotective agents. The latter has only been tested and reproduced in an animal model and not in a human situation. This means there is no effective preventive strategy in the prevention of xerostomia.

Relieving xerostomia follows the strategy of stimulating the residual capacity in addition to symptomatic relief. Stimulating residual gland capacity can be done by gustatoire and tactile sialogogues. Symptomatic relief comes through the use of beverages, home remedies and, of course, the use of artificial saliva. These can be divided in a mucin or a carboxy methyl cellulose type saliva substitutes.

The use of artificial salivary substitutes normally only provides limited relief. The most useful indices for saliva substitutes are situations with a lot of difficulties in speech and nocturnal discomfort. The success of using saliva substitutes is strictly dependent on the instructions delivered by the physician or the dental hygienist along with the prescription. The saliva substitutes can be easily applied with an atomizer. The patient should moisten the oral cavity abundantly, spread the substitutes all over the oral cavity, and swallow the surplus. As soon as the sensation of dryness returns, the treatment should be repeated.

Radiation Caries
Radiation caries can develop very fast when preventive measures are not adequate. One must remember that the risk is life long due to the reduced saliva production and changes in the quality of saliva. Together with a reduced oral clearance, dietary changes, and a shift in oral flora toward a more cariogenic bacteria, radiation caries can develop rapidly; this means within a few months. Typical characteristics of this type of caries are development of lesions on the free surfaces, like the cervical or buccal layers, and sometimes even at the incisal edges of the teeth.

It has been shown that proper oral hygiene alone is an in adequate safeguard against radiation caries. Topical fluoride application with individual trays is mandatory in all patients who receive more than 40 Gy in their oral cavity. Before the start of the radiation course, the dental hygienist will make impressions to fabricate the flexible fluoride carriers with which the patient has to apply the neutral 1 percent sodium fluoridegel every second day from the onset of radiotherapy. Acidulated gels should not be used in irradiated patients because they may lead to significant decalcification without sufficient remineralisation potential in the presence of hyposalivation. They may also cause mucosal irritation with burning pain, erythema, and even ulcerations. The patients apply the fluoride gel for 5–10 minutes in the fluoride carrier every second day, preferable just before bedtime.

Monique: I am sorry to say that this sentence does not make sense as it is written. I tried to rewrite it below so please review. If it is wrong please rewrite the original using short declarative sentences, even repeating the ‘intro’ if necessary so I can understand what you mean. The more sentences you use the better chance I have understanding your meaning and then rewriting it as one.

For the prevention of radiation caries it is important to have optimal oral hygiene and employ the life long use of NaF-gel every second day (reduced use only in cases of recovered salivary flow) in combination with at least bi-yearly dental evaluations.

Osteoradionecrosis
Hypovascularity and fibrosis of soft tissues are the common end result of irradia¬tion-induced tissue injury. Therefore, it is obvious that irradiated bone renders a poor response to trauma and infection. Osteoradionecrosis (ORN), means bone death due to radiation, and it is the most serious complication of radiotherapy for head and neck cancer.

The best method to control osteoradionecrosis is prevention. The prime goal should be to optimize the condition of the patient’s dentition so that high-risk procedures, such as tooth extractions and periodontal surgery will not have to be performed post-irradiation. The denture policy post-irradiation is an important part of ORN prevention. Irradiated mucosa is very vulnerable and easily damaged, and aggravated by the hyposalivation condition. The policy followed most often is to wait 3 months after finishing the irradiation treatment before placing or replacing the dentures. This period is extended to 6 months if pre-irradiation extractions were done.

Tooth Development Deformation
Chemotherapy affects the development of the craniofacial complex, including the teeth. Several oral abnormalities are described such as agenesis, microdontia, and crown and root abnormalities. If chemotherapy starts from the age of 3 years on, one may expect detrimental effects on the development of permanent teeth because at that time they are in a highly proliferating and differentiating phase. Due to variations in the degree of development, teeth may be affected differently in localization and severity by chemotherapy.

After the oncology treatment, relief of oral dryness, discomfort and possibly related consequences of radiation caries is the main purpose of post-irradiation oral care. The additional oral care aims to prevent post-irradiation extractions and, thus, osteoradionecrosis (ORN). A high level of oral hygiene has to be maintained indefinitely in all patients, whereas topical fluoride applications need to be continued life long in most dentulous patients who received radiotherapy. Patients must be kept on a regular dental recall schedule. Dental and dental hygienist controls are needed every 3 months during the first year post-irradiation, which in our situation are done in conjuncti¬on with the oncologic controls. After one year, follow-up controls need to be done every 3-6 months, depending on individual factors such as hygiene level and degree of xerostomia.

With the proportional increase of the ageing population, the dental hygienist in the public practice has to take a more important role in a patient’s oral care following cancer treatment.
Better education of dental hygienists in the field of supportive oral care is therefore a prerequisite.

Images:
Mucositis

Ritterspray

Ritterspray close-up

Fluoride carriers

Fluoride carriers in situ

Dental caries

References

1. Sonis ST, Fey EG. Oral complications of cancer therapy. Oncology (Huntingt) 2002,16:680-6.
2. Vissink A, Jansma J, Spijkervet FKL, Burlage FR, Coppes RP. Oral sequelae of head and neck radiotherapy. Crit Rev Oral Biol Med 2003,14:199-212.
3. Vissink A, Burlage FR, Spijkervet FKL, Jansma J, Coppes RP. Prevention and treatment of the consequences of head and neck radiotherapy. Crit Rev Oral Biol Med 2003,14:213-25.
4. Bellm LA, Epstein JB, Rose-Ped A, Martin P, Fuchs HJ. Patient reports of complications of bone marrow transplantation. Support Care Cancer 2000,8:33-9.
5. Rose-Ped AM, Bellm LA, Epstein JB, Trotti A, Gwede C, Fuchs HJ. Complications of radiation therapy for head and neck cancers - The patient's perspective. Cancer Nursing 2002,25:461-7.
6. Sonis ST. The pathobiology of mucositis. Nature Reviews Cancer 2004,4:277-84.
7. Rubenstein EB, Peterson DE, Schubert M, Keefe D, McGuire D, Epstein J, Elting LS, Fox PC, Cooksley C, Sonis ST. Clinical practice guidelines for the prevention and treatment of cancer therapy-induced oral and gastrointestinal mucositis. Cancer 2004,100:2026-46.

Contact Info
You may contact Monique A. Stokman or Dr. Fred K.L. Spijkervet at:
University Medical Center Groningen
Depart. of Oral and Maxillofacial Surgery
P.O. Box 30.001
9700 RB GRONINGEN
The Netherlands
E-mail: m.a.stokman@kchir.umcg.nl
f.k.l.spijkervet@kchir.umcg.nl

^{This article first appeared in the UK edition of Dental Tribune}