DENTAL MANAGEMENT OF PATIENTS ON SYSTEMIC CHEMOTHERAPY FOR MALIGNANT OISEASE
Destruction of malignant cells by tumoricidal chemotherapeutic drugs has proved an effective treatment for a variety of malignancies. Like radidtherapy, the antitumor effectof cancer chemotherapeutic agents is based on their ability to destroy or retard the division of rapidly proliferating
cells, such as tumor cells, nonspeclfically, Unfortunately, normal host cells that havea high mitotic index arealso adversely affected. Normal cells most affected are the epithelium of the gastrointestinal tract (including oral cavity) and the cells of the bone marrow.
Effects on Oral Mucosa
Many chemotherapeutic agents reduce the normal turnover rate of oral epithelium, which results in atrophic thinning of the oral -mucosa manifested clinically as painful, erythematous, and ulcerative mucosal
surfaces in the mouth. The effects are most noted on the unattached mucosa and rarely seen on gingival surfaces. These changes are seen within 1 week of the onset ‘of the administration of the antitumor agents.
The effects are usually self-limiting, and spontaneoushealing occurs in 2 to 3 weeks after cessation of the agent.
Effects on Hematopoietic System
Myelosuppression, as manifested by leukopenia, neutropenia, thrombocytopenia, and’ anemia, is a common
sequela ofseveralforms of cancer chemotherapy. Within 2 weeks of the beginning of chemotherapy administration, the white blood cell count falls to an extremely low level. The effect of .myelosuppresston in the oral cavity is marginal gingivitis. Mild infections may develop, and bleeding
from the girigiva is common. If the neutropenia is severe and prolonged, severe infections may develop. The microorganisms involved in these infections may be overgrowths of the usual oral flora, especially fungi; however, other microorganisms may be causative. Thrombocytopenia
can be marked, and spontaneous bleeding may occur. This is especially common in the oral cavity after oral hygiene measures. Recovery from myelosuppression is usually complete 3weeks after cessation of chemotherapy .
Effects on Oral.Microbiology
Chemotherapeutic agents, because of their immunosuppressive side effect, cause profound changes in the oral flora. For example, overgrowth of indigenous microbes, super infection with gram-negative bacilli, and opportunistic infections are all common sequelae and lead to patient discomfort and morbidity. Systemic infections are responsible for about 70% of the deaths in patients receiving myelosuppressive cancer chemotherapy.26,27 Oral microorganisms have been shown to be a common source of bacteremia in these patlents.s” Thus most patients who
are on chemotherapy are treated concomitantly with systemic antimicrobial agents. However, in spite of these regimens,
patients· requently develop overgrowth of some
organism , most commonly the Candida Spp.28-30 .
General Dental Management
In general, the principles of dental management for the patient who has had or will have radiotherapy apply equally well to the patient who has had or will have chernotherapy.U-V However, because of the intermittent
nature of the chemotherapy delivered in many instances, the minimal effects on the vasculature, and the almost normal state of the individual between-chemotherapeutic administrations, dental management can be much easier. The effects of the chemotherapy are almost always temporary, and, with the passage of time, systemic health
improves to optimal levels, which allows almost routine dental management .
Patients who have begun chemotherapy must maintain scrupulous oral hygiene. Thfs is difficult tn the face of mucositis and ulceration, which frequently occur. No dental procedures should be performed on any patient ‘receiving chemotherapy whose white blood cell and
piatelet status is unknown. In general, patients who have a. white blood cell count greater than or equal to 2000· rnm”, with at least 20% polymorphonuclear leukocytes and a platelet count greater than or equal to 50,000 mm3, can be treated in routine fashion. Prophylactic antibiotics
should be administered if the patient has had chemotherapy within 3 weeks of dental treatment. If the white blood cell count and platelet levels fall below those spectfled minimal oral care should be practiced, because
infection, severe blee ing, or both can occur. The patient may even need to avo d flossing and to use an extremely -soft toothbrush durin g these periods. Any removable dental appliance should be left out at these times to prevent ulceration of the fragile mucosa.
Treatment of Oral Candldosls
Initial treatment of candidosis is with topical application of an antifungal medication.P’ The advantage of using topical medication is that systemic side effects are minimized. Similarly in patients with persistent infection,
advantage can be gained by continuing topical agents in add~ign to systemic medications. The use of this combination may allow a reduced dose and duration of systemic administration of the antifungal medication and also may reduce the poterittalstde effects.
Another widely prescribed medication for oral candidosis is chlorhexidine mouth rinse. Chlorhexidine .(Peridex) has been shown to have potent antibacterial and antifungal properties in vitro. Its in vivo effects are
iess we\\ dOC ‘ll\ented, e~pe<:ia\\.y tot use against Caniiida
spp. in immunosuppressed individuals.3,33 However, it is used in most of such patients on the basis that it probably does no harm and may prove beneficial in many instances.