Oral complications of cancer therapies. Mucosal alterations.

The initial effect of anticancer therapy, such as radiation and chemotherapy, is on the rapidly proliferating cells of the oral epithelium. As a consequence, the epithelium may show atrophy and ulceration. The sites of these alterations are related to the rate of epithelial proliferation. Regions of rapid proliferation, such as the oral lining mucosa, show a greater frequency of ulceration than masticatory mucosa or skin. Subsequent changes in the mucosa reflect damage to connective tissue, including fibroblasts and blood vessels. This results in hyalinization of collagen, hypovascularity, and ischemia. Indirect effects of anticancer therapy may include granulocytopenia and reduced salivary secretion, so that the protective mucin coating of the epithelium is compromised. These changes result in tissue with reduced barrier function and impaired ability to heal and to resist entry of pathogens, thus increasing the risk of systemic infections.