Emerging evidence on the pathobiology of mucositis

Oral complications in hematopoietic stem cell recipients: the role of inflammation

Hematopoietic stem cell transplantation (HSCT) is widely used as a potentially curative treatment for patients with various hematological malignancies, bone marrow failure syndromes, and congenital immune deficiencies. The prevalence of oral complications in both autologous and allogeneic HSCT recipients remains high, despite advances in transplant medicine and in supportive care. Frequently encountered oral complications include mucositis, infections, oral dryness, taste changes, and graft versus host disease in allogeneic HSCT. Oral complications are associated with substantial morbidity and in some cases with increased mortality and may significantly affect quality of life, even many years after HSCT. Inflammatory processes are key in the pathobiology of most oral complications in HSCT recipients. This review article will discuss frequently encountered oral complications associated with HSCT focusing on the inflammatory pathways and inflammatory mediators involved in their pathogenesis.

Chemotherapy or radiation-induced oral mucositis

Oral mucositis is a significant toxicity of systemic chemotherapy and of radiation therapy to the head and neck region. The morbidity of oral mucositis can include pain, nutritional compromise, impact on quality of life, alteration in cancer therapy, risk for infection, and economic costs. Management includes general symptomatic support and targeted therapeutic interventions for the prevention or treatment of oral mucositis. Evidence-based clinical practice guidelines are available to guide clinicians in the selection of effective management strategies.

MASCC/ISOO clinical practice guidelines for the management of mucositis secondary to cancer therapy

BACKGROUND

Mucositis is a highly significant, and sometimes dose‐limiting, toxicity of cancer therapy. The goal of this systematic review was to update the Multinational Association of Supportive Care in Cancer and International Society of Oral Oncology (MASCC/ISOO) Clinical Practice Guidelines for mucositis.

METHODS

A literature search was conducted to identify eligible published articles, based on predefined inclusion/exclusion criteria. Each article was independently reviewed by 2 reviewers. Studies were rated according to the presence of major and minor flaws as per previously published criteria. The body of evidence for each intervention, in each treatment setting, was assigned a level of evidence, based on previously published criteria. Guidelines were developed based on the level of evidence, with 3 possible guideline determinations: recommendation, suggestion, or no guideline possible.

RESULTS

The literature search identified 8279 papers, 1032 of which were retrieved for detailed evaluation based on titles and abstracts. Of these, 570 qualified for final inclusion in the systematic reviews. Sixteen new guidelines were developed for or against the use of various interventions in specific treatment settings. In total, the MASCC/ISOO Mucositis Guidelines now include 32 guidelines: 22 for oral mucositis and 10 for gastrointestinal mucositis. This article describes these updated guidelines.

CONCLUSIONS

The updated MASCC/ISOO Clinical Practice Guidelines for mucositis will help clinicians provide evidence‐based management of mucositis secondary to cancer therapy. Cancer 2014;120:1453–1461. © 2014 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

Mucositis is a highly significant, and sometimes dose‐limiting, toxicity of cancer therapy. This article presents evidence‐based clinical practice guidelines for the management of mucositis.

TLR4/PKC-mediated tight junction modulation: a clinical marker of chemotherapy-induced gut toxicity?

Chemotherapy-induced gut toxicity is a major clinical and economic burden to oncology practice. The mechanisms responsible for its development are ill defined, hampering the development of therapeutic interventions. In light of newly published research foci and clinical practice guidelines in supportive care in cancer, there has been renewed interest in the role tight junctions play in the pathobiology of chemotherapy-induced gut toxicity. Several preclinical studies have identified molecular defects in intestinal tight junctions following chemotherapy. Despite these findings, the mechanisms responsible for chemotherapy-induced tight junction disruption remain unclear. Recent research has highlighted roles for toll-like receptor 4 and protein kinase C signalling in the regulation of tight junctions. This critical review therefore aims to provide evidence linking toll-like receptor 4 expression, protein kinase C activation and tight junction disruption and their relationship to clinical toxicity.

Oral mucosal injury caused by cancer therapies: current management and new frontiers in research

This invited update is designed to provide a summary of the state-of-the-science regarding oral mucosal injury (oral mucositis) caused by conventional and emerging cancer therapies. Current modeling of oral mucositis pathobiology as well as evidence-based clinical practice guidelines for prevention and treatment of oral mucositis are presented. In addition, studies addressing oral mucositis as published in the Journal of Oral Pathology and Medicine 2008-2013 are specifically highlighted in this context. Key research directions in basic and translational science associated with mucosal toxicity caused by cancer therapies are also delineated as a basis for identifying pathobiologic and pharmacogenomic targets for interventions. This collective portfolio of research and its ongoing incorporation into clinical practice is setting the stage for the clinician in the future to predict mucosal toxicity risk and tailor therapeutic interventions to the individual oncology patient accordingly.

Investigation of effect of nutritional drink on chemotherapy-induced mucosal injury and tumor growth in an established animal model

Chemotherapy-induced mucositis represents a significant burden to quality of life and healthcare costs, and may be improved through enhanced nutritional status. We first determined the safety of two nutritional drinks (plus placebo), and then potential gut protection in tumor-bearing rats in a model of methotrexate-induced mucositis. In study 1, animals were fed one of two test diets (or placebo or control chow pellets) for a total of 60 days and were monitored daily. All diets were found to be safe to administer. In study 2, after seven days of receiving diets, a Dark Agouti Mammary Adenocarcinoma (DAMA) was transplanted subcutaneously. Ten days after starting diets, animals had 2 mg/kg intramuscular methotrexate administered on two consecutive days; after this time, all animals were given soaked chow. Animals were monitored daily for changes in bodyweight, tumor burden and general health. Animals were killed 10, 12 and 16 days after initially starting diets, and tissues were collected at necropsy. In study 1, animals receiving diets had gained 0.8% and 10.8% of their starting bodyweight after 60 days, placebo animals 4.4%, and animals fed on standard chow had gained 15.1%. In study 2, there was no significant influence of test diet on bodyweight, organ weight, tumor burden or biochemical parameters. Only animals treated with MTX exhibited diarrhea, although animals receiving Diet A and Diet C showed a non-significant increase in incidence of diarrhea. Administration of these nutritional drinks did not improve symptoms of mucositis.