Mucositis is defined as erythematous and ulcerative lesions of the gastrointestinal tract (GIT) following chemotherapy, radiotherapy (particularly radiotherapy to the head, neck or oesophagus) or high dose chemotherapy followed by blood and marrow transplant (BMT).
The mucosal lining of the GIT, including the oral mucosa is a prime target for treatment related toxicity by virtue of its rapid cell turnover rate.
Oral mucositis is experienced by the majority of people who receive stomatotoxic chemotherapy, radiation therapy to the head and neck region, or who undergo BMT. The incidence of mucositis varies by patient diagnosis, age, level of oral health, and type, dose and frequency of drug administration. Additionally, the incidence of radiation induced mucositis is dependent upon a number of factors including the dose of radiotherapy, hyperfractionation, concurrent treatment, anatomic subsite exposed, and individual patient predisposition.
Recent literature indicates that mucositis can affect:
- approximately 5-20% of patients treated with chemotherapy for solid tumours
- 60-100% of patients on myeloablative regimens in preparation for BMTr
- up to 100% of patients receiving therapy for the treatment of head and neck cancer.r
Oral mucositis typically occurs 2 to 3 weeks from the commencement of treatment, but may happen at around 5 days after BMT, and may last for 2 to 3 weeks after completion of treatment. Radiation induced mucositis is more severe and of longer duration (3-12 weeks) when compared to chemotherapy induced mucositis. For patients undergoing combined radiotherapy and chemotherapy treatments, this shortens the onset and typically occurs within 7-12 days of commencement of treatment, and the concurrent treatment also exacerbates its severity, and prolongs its duration.
Radiotherapy: Oral mucositis is a major dose-limiting side effect, in head and neck patients receiving radiotherapy, and has the potential to cause significant treatment interruptions.r The dose of radiation is correlated with mucositis, doses of 50-65Gy had incidence rates of greater than or equal to grade 3 toxicity at 56%, whilst doses of greater than 65Gy had incidence rates greater than or equal to grade 3 toxicity of 72%. Tumour location is also correlated to the incidence of mucositis, with nasopharyngeal and oropharyngeal tumours being associated with an increased risk. The degree and duration of mucositis in patients treated with radiotherapy is related to the dose of radiotherapy, hyperfractionation, concurrent treatment, anatomic subsite exposed, and individual patient predisposition. It is exacerbated by smoking, alcohol consumption, and other predisposing factors such as xerostomia or infection.
Chemotherapy: The drugs with the highest stomatotoxic potential include the antimetabolites, antitumour antibiotics and the tubulin interactive agents. The intensity of mucositis increases with higher dosages or combinations of cytotoxic drugs; even drugs that are not usually stomatoxic, e.g. cyclophosphamide can cause cellular damage to the mucosa at high doses. For neutropenic patients, mucositis represents a clinically significant risk factor for febrile neutropenia, and when severe may compromise the airway.r