Mucositis: Its Occurrence, Consequences, and Treatment in the Oncology Setting

INTRODUCTION: Mucositis induced by antineoplastic drugs is an important, dose-limiting, and costly side effect of cancer therapy. The ulcerative lesions produced by mucotoxic chemoradiotherapy are painful, restrict oral intake and, importantly, act as sites of secondary infection and portals of entry for the endogenous oral flora. The overall frequency of mucositis varies and is influenced by the patient's diagnosis, age, level of oral health, and type, dose, and frequency of drug administration. Some degree of mucositis occurs in approximately 40% of patients who receive cancer chemotherapy. Approximately one-half of those individuals develop lesions of such severity as to require modification of their cancer treatment and/or parenteral analgesia. The condition's incidence is consistently higher among patients undergoing conditioning therapy for bone marrow/peripheral blood progenitor cell transplantation, continuous infusion therapy for breast and colon cancer, and therapy for tumors of the head and neck associating concomitant chemotherapy and radiotherapy. Among patients in the high-risk protocols, severe mucositis occurs with a frequency in excess of 60%. Concomitant with mucositis is often a chemotherapy-induced myelosuppression. The neutropenia that results puts the patient with oral mucositis at significant risk for systemic infection. Patients with mucositis and neutropenia have a relative risk of septicemia that is greater than four times that of individuals without mucositis. The morbidity of all mucositis can be profound. It is estimated that approximately 15% of patients treated with radical radiotherapy to the oral cavity and oral pharynx will require hospitalization for treatment-related complication. In addition, severe oral mucositis may interfere with the ability to deliver the intended course of therapy, leading to significant interruptions in treatment, and possibly impacting on local tumor control and patient survival. It is also not unusual for mucositis to necessitate delays in cancer chemotherapy particularly with those agents that are known to be mucotoxic, including 5-fluorouracil with or without folinic acid, methotrexate, doxorubicin, etoposide, melphalan, cytosine arabinoside and cyclophosphamide. In addition to its impact on a patient's treatment course, on quality of life, and morbidity and mortality, mucositis can also have a significant economic cost. This is particularly true in the autologous and allogeneic bone marrow transplant settings for hematologic malignancies, where the length of hospital stay may be prolonged due to severe mucositis.