Oral and intestinal mucositis - causes and possible treatments.

Chemotherapy and radiotherapy, whilst highly effective in the treatment of neoplasia, can also cause damage to healthy tissue. In particular, the alimentary tract may be badly affected. Severe inflammation, lesioning and ulceration can occur. Patients may experience intense pain, nausea and gastro-enteritis. They are also highly susceptible to infection. The disorder (mucositis) is a dose-limiting toxicity of therapy and affects around 500 000 patients world-wide annually. Oral and intestinal mucositis is multi-factorial in nature. The disruption or loss of rapidly dividing epithelial progenitor cells is a trigger for the onset of the disorder. However, the actual dysfunction that manifests and its severity and duration are greatly influenced by changes in other cell populations, immune responses and the effects of oral/gut flora. This complexity has hampered the development of effective palliative or preventative measures. Recent studies have concentrated on the use of bioactive/growth factors, hormones or interleukins to modify epithelial metabolism and reduce the susceptibility of the tract to mucositis. Some of these treatments appear to have considerable potential and are at present under clinical evaluation. This overview deals with the cellular changes and host responses that may lead to the development of mucositis of the oral cavity and gastrointestinal tract, and the potential of existing and novel palliative measures to limit or prevent the disorder. Presently available treatments do not prevent mucositis, but can limit its severity if used in combination. Poor oral health and existing epithelial damage predispose patients to mucositis. The elimination of dental problems or the minimization of existing damage to the alimentary tract, prior to the commencement of therapy, lowers their susceptibility. Measures that reduce the flora of the tract, before therapy, can also be helpful. Increased production of free radicals and the induction of inflammation are early events in the onset of mucositis. Prophylactic administration of scavengers or anti-inflammatories can partially counteract or limit some of these therapy-mediated effects, as can the use of cryotherapy. The regular use of mouthwashes, mouth coatings, antibiotics and analgesics is essential, prior to and during loss and ablation of the epithelial layer. Granulocyte-macrophage colony-stimulating factor/granulocyte colony-stimulating factor or the use of laser light therapy may aid restitution and repair. Glutamine supplements may be beneficial in the repair/recovery phase.