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High-dose
chemotherapy and radiation therapy selectively affect rapidly-dividing
cells, both cancerous and non-cancerous. The rapidly dividing
basal cells of the oral mucosa are among the body cells vulnerable
to damage by chemotherapy and radiation therapies. The specific
damage includes the shedding of the outer mucosal layer (desquamation),
breaks or holes in the skin layers (ulcerations),
and a general wasting of the tissues (atrophy)
(Woo
et al., 1993; Epstein
et al., 1999). In addition, patients undergoing chemotherapy
or radiation therapy are more prone to cuts, nicks, and lacerations
caused by chewing because of their compromised mucosa. Such lesions
have an increased risk for bacterial infections, therefore decreasing
the bacterial load intraorally by maintaining good oral hygiene
and using anti-bacterial mouth rinses can decrease the risk of
systemic infections due to ulcerative mucositis (Seto
et al., 1985).
The pain associated
with ulcerative mucositis can inhibit patients from eating, drinking,
or taking oral medications. The presence of mucositis has been
associated with decreasing absolute neutrophil count (ANC) levels.
A likely explanation for this observation is that neutrophils
and mucosal basal cells are actively reproducing cells that tend
to be damaged by chemotherapeutic agents and recover in parallel.
These lesions tend to resolve when the ANC return to normal, indicating
normal mitotic activity of basal cells. Healing of mucosal tissue
is not dependent on the return of ANC levels.
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