Efficacy of glutamine in the prevention of oral mucositis and acute radiation-induced esophagitis: a retrospective study

Summary of the best evidence for nutritional support programs in nasopharyngeal carcinoma patients undergoing radiotherapy

Objective

To evaluate and summarize the best evidence for nutritional support in patients receiving radiotherapy for nasopharyngeal carcinoma and to offer guidance for clinical practice.

Background

Patients with nasopharyngeal carcinoma undergoing radiotherapy often experience a high prevalence of malnutrition, and there is a lack of compiled guideline recommendations, which complicates the provision of a reference for clinical nursing.

Methods

A systematic literature search revealed the best evidence of nutritional support for nasopharyngeal carcinoma patients undergoing radiotherapy. Included in the review were various types of literature, such as clinical guidelines, expert consensus, systematic evaluations, meta-analyses, evidence summaries, and original studies. The evidence was graded according to the Australian Joanna Briggs Institute Centre for Evidence-Based Health Care Evidence Pre-Grading System (2016 version). Data were gathered from a range of sources, including BMJ Best Practice, the Scottish Intercollegiate Guidelines Network, the Cochrane Library, Embase, PubMed, Web of Science, CINAL, CNKI, the WanFang database, SinoMed, the Yi Maitong Guidelines Network, Dingxiangyuan, the Chinese Nutrition Society, the European Society for Clinical Nutrition and Metabolism website, and the American Society for Parenteral and Enteral Nutrition website. The search spanned from January 2013 to 2023.

Results

A comprehensive review identified a total of 3,207 articles, comprising six guidelines, eight expert consensus articles, four systematic evaluations, five randomized controlled trials, two cohort trials, and two observational studies. From these articles, we synthesized 63 pieces of evidence spanning six domains: nutritional risk screening and assessment, nutrient requirements, nutritional support, management of nutritional symptoms, functional exercise, and nutritional monitoring and follow-up.

Conclusion

A total of lines of evidence supporting nutritional support for nasopharyngeal carcinoma patients receiving radiotherapy were summarized. However, the evidence should be combined with the actual clinical situation, and it should be validated in the future by combining large-sample and multicenter studies to provide a more scientific and beneficial nutritional support program for nasopharyngeal carcinoma patients receiving radiotherapy.

Susceptibility to radiation adverse effects in veterans with Gulf War illness and healthy civilians

We evaluated whether veterans with Gulf War illness (VGWI) report greater ionizing radiation adverse effects (RadAEs) than controls; whether radiation-sensitivity is tied to reported chemical-sensitivity; and whether environmental exposures are apparent risk factors for reported RadAEs (rRadAEs). 81 participants (41 VGWI, 40 controls) rated exposure to, and rRadAEs from, four radiation types. The relations of RadAE-propensity (defined as the ratio of rRadAEs to summed radiation exposures) to Gulf War illness (GWI) presence and severity, and to reported chemical-sensitivity were assessed. Ordinal logistic regression evaluated exposure prediction of RadAE-propensity in the full sample, in VGWI, and stratified by age and chemical-sensitivity. RadAE-propensity was increased in VGWI (vs. controls) and related to GWI severity (p < 0.01) and chemical-sensitivity (p < 0.01). Past carbon monoxide (CO) exposure emerged as a strong, robust predictor of RadAE-propensity on univariable and multivariable analyses (p < 0.001 on multivariable assessment, without and with adjustment for VGWI case status), retaining significance in age-stratified and chemical-sensitivity-stratified replication analyses. Thus, RadAE-propensity, a newly-described GWI-feature, relates to chemical-sensitivity, and is predicted by CO exposure-both features reported for nonionizing radiation sensitivity, consistent with shared mitochondrial/oxidative toxicity across radiation frequencies. Greater RadAE vulnerability fits an emerging picture of heightened drug/chemical susceptibility in VGWI.

Radioprotective countermeasures for radiation injury (Review)

A series of physiological and pathological changes occur after radiotherapy and accidental exposure to ionizing radiation (IR). These changes cause serious damage to human tissues and can lead to death. Radioprotective countermeasures are radioprotective agents that prevent and reduce IR injury or have therapeutic effects. Based on a good understanding of radiobiology, a number of protective agents have achieved positive results in early clinical trials. The present review grouped known radioprotective agents according to biochemical categories and potential clinical use, and reviewed radiation countermeasures, i.e., radioprotectors, radiation mitigators and radiotherapeutic agents, with an emphasis on their current status and research progress. The aim of the present review is to facilitate the selection and application of suitable radioprotectors for clinicians and researchers, to prevent or reduce IR injury.

Oxidative Stress and Chemoradiation-Induced Oral Mucositis: A Scoping Review of In Vitro, In Vivo and Clinical Studies

Chemoradiation-induced mucositis is a debilitating condition of the gastrointestinal tract eventuating from antineoplastic treatment. It is believed to occur primarily due to oxidative stress mechanisms, which generate Reactive Oxygen Species (ROS). The aim of this scoping review was to assess the role of oxidative stress in the development of Oral Mucositis (OM). Studies from the literature, published in MEDLINE and SCOPUS, that evaluated the oxidative stress pathways or antioxidant interventions for OM, were retrieved to elucidate the current understanding of their relationship. Studies failing inclusion criteria were excluded, and those suitable underwent data extraction, using a predefined data extraction table. Eighty-nine articles fulfilled criteria, and these were sub-stratified into models of study (in vitro, in vivo, or clinical) for evaluation. Thirty-five clinical studies evaluated antioxidant interventions on OM's severity, duration, and pain, amongst other attributes. A number of clinical studies sought to elucidate the protective or therapeutic effects of compounds that had been pre-determined to have antioxidant properties, without directly assessing oxidative stress parameters (these were deemed "indirect evidence"). Forty-seven in vivo studies assessed the capacity of various compounds to prevent OM. Findings were mostly consistent, reporting reduced OM severity associated with a reduction in ROS, malondialdehyde (MDA), myeloperoxidase (MPO), but higher glutathione (GSH) and superoxide dismutase (SOD) activity or expression. Twenty-one in vitro studies assessed potential OM therapeutic interventions. The majority demonstrated successful a reduction in ROS, and in select studies, secondary molecules were assessed to identify the mechanism. In summary, this review highlighted numerous oxidative stress pathways involved in OM pathogenesis, which may inform the development of novel therapeutic targets.

Effects of Immunonutrition in Head and Neck Cancer Patients Undergoing Cancer Treatment – A Systematic Review

Background and Aims

Malnutrition is prevalent among head and neck cancer (HNC) patients and leads to undesirable outcomes such as reduced treatment response and increased treatment-related side effects. This systematic review summarizes the recent evidence regarding the effect of immunonutrition in HNC patients undergoing radiotherapy and chemotherapy.

Methods

A literature search was conducted of the CENTRAL, ProQuest, MEDLINE, EBSCOhost, Web of Science and CINAHL databases; and further supplemented with internet and manual searches. Studies published between January 2011 and May 2021 were identified, screened, retrieved, and data extraction was performed.

Results

Twenty studies involving 1535 patients were included, 15 were randomized controlled trials (RCTs), three were retrospective study and two were comparative cohort studies. Five out of seven studies reported improvement or maintenance of nutrition status with continuous supplementation using immunonutrient-enriched formula. Three studies reported functional status as an outcome, with one study reporting significant improvement, one study reporting maintenance, and another study reporting no difference in the functional status of patients supplemented with immunonutrient-enriched formulas. Supplementation with glutamine did not reduce the overall incidence of mucositis but delayed the onset of oral mucositis and had significantly less incidence of severe oral mucositis.

Conclusion

Supplementation with immunonutrient-enriched formulas in HNC patients during radiotherapy and chemotherapy may improve or maintain nutrition status. Supplementation with glutamine during HNC radiotherapy and chemotherapy may delay the onset of oral mucositis and reduce incidences of severe oral mucositis. Further investigations are required, focusing on the timing, dosage, and duration of immunonutrition.

Systematic Review Registration: PROSPERO, identifier CRD42021241817.

Efficacy of Nutrients in Reducing the Symptoms of Radiation Induced Oral Mucositis in a Hamster Model

Radiation-induced oral mucositis (RIOM) is a painful, dose-limiting toxicity in cancer therapy. RIOM was induced by radiation on the left buccal pouch mucosa of Golden Syrian hamsters (n = 8/group). Animals were treated topically with polyphenols (Curcumin or Quercetin) or amino acids/metabolite mixtures (Alanyl-Glutamine or Arginine + Glutamine + β-Hydroxy β-methylbutyric acid (Arg/Gln/HMB)) for over 20 day. Progression of RIOM was assessed using a standard visual scoring six-point scale, for differences in severity of mucositis (score ≥3) (Chi-square analysis) and in the daily group scores (Mann-Whitney rank sum test). Compared to the controls, there was a significant reduction in number of days with severe RIOM (score ≥3) in the treatment groups: Curcumin (50 μg/ml) = 17%; Control = 38.5%, p < 0.001; Quercetin (50 μg/ml) = 27.6% and Quercetin (100 μg/ml) = 25%; Control = 41.3%, p = 0.007 and p = 0.001, respectively; Arg/Gln/HMB (50 mg/ml) = 31.9%; Control = 50.0%, p = 0.040. In addition, Curcumin (50 μg/ml), Quercetin (100 μg/ml) and Arg/Gln/HMB (100 mg/ml) groups had lower mucositis scores (≥3) on at least two consecutive time points over the course of the study than their respective controls. There were no significant group differences in deaths or body weight. This study demonstrates the potential benefits of topical application of either plant polyphenols or amino acid/metabolite mixtures in addressing severity and progression of RIOM.

A Bioadhesive Barrier-Forming Oral Liquid Gel Improved Oral Mucositis and Nutritional Status in Patients With Head and Neck Cancers Undergoing Radiotherapy: A Retrospective Single Center Study

Background

Episil^® is a bioadhesive barrier-forming oral liquid gel that can relieve oral mucositis (OM) caused by radiotherapy (RT) and hence relieves pain effectively. In this study, we observed the effects of Episil^® on the OM and nutritional status of patients with head and neck cancers (HNCs) undergoing RT.

Methods

A total of 50 HNC patients were divided into the Episil^® (25 patients) and control (25 patients) groups. Patients in the Episil^® group were sprayed with Episil^®. In the control group, the kangfuxin solution or Kangsu™ oral gargle was used. Medical staff assessed the OM extent and timing as well as the nutritional status during treatment and recorded adverse reactions other than OM. The nutritional status assessment included the following indicators: Patient Generated-Subjective Global Assessment (PG-SGA) score, body mass index (BMI), body weight, albumin levels, and other hematological indicators.

Results

The incidence of high-level OM (III–IV) after RT was lower in the Episil^® group than in the control group (P < 0.05). Nutritional status assessments showed that the Episil^® group had a lower percentage of weight loss than the control group at weeks 4 and 7 after RT. Similar results were also obtained for BMI and albumin levels (P < 0.05). Moreover, according to PG-SGA scores, fewer patients in the Episil^® group were malnourished and more patients were well-nourished (P < 0.05) compared with the control group.

Conclusion

Episil^® effectively improved OM and malnutrition in HNC patients who received RT and has a good clinical application value.

Role of Glutamine in the Management of Oral Mucositis in Patients with Cancer: A Meta-Analysis of Randomized Controlled Trials

As the effectiveness of glutamine supplementation for oral mucositis (OM) in patients with cancer remains controversial, a comprehensive summary and analysis of available evidence is necessary. The aim of the present meta-analysis was to evaluate the benefits of glutamine supplementation on OM and OM-related adverse reactions in patients with cancer receiving chemotherapy (CT) and/or radiotherapy (RT), using data from randomized controlled trials (RCTs). The PubMed, Embase, Cochrane Library, and Web of Science databases were searched for RCTs on the use of glutamine for treating OM, published until September 11, 2020. Risk ratios (RRs) or standardized mean differences (SMDs) and 95% confidence intervals (CI) were calculated using RevMan 5.3. Fifteen studies with 988 participants were included. Glutamine did not reduce the incidence of OM (RR 0.94), but it reduced the severity of OM (SMD -0.73) and incidence of severe OM (RR 0.41). Additionally, glutamine reduced the incidence of opioid analgesic use (RR 0.84), feeding tube use (RR 0.46), hospitalization (RR 0.39), and treatment interruption (RR 0.49) caused by OM. Glutamine effectively improved OM and reduced OM-related adverse reactions in patients with cancer receiving CT and/or RT.

Effects of glutamine for prevention of radiation-induced esophagitis: a double-blind placebo-controlled trial

Purpose Acute radiation-induced esophagitis (ARIE) leads to treatment delays, decreased quality of life (QOL), and secondary adverse events such as weight loss. Grade 3 ARIE occurs in 15%-30% of patients undergoing radiotherapy to the esophagus, leading to disruption or discontinuation of treatment. The purpose of this study was to assess the effects of glutamine, a common nutritional supplement, on ARIE in patients with thoracic malignancies. Patients and methods This double-blind, placebo-controlled trial enrolled patients with advanced thoracic malignancies receiving concurrent chemotherapy/radiotherapy or radiotherapy alone, with radiation doses to the esophagus ≥45 Gy. Patients were randomized (1:1) to receive 4 g of glutamine or glycine placebo twice daily. The primary objective was to determine whether glutamine decreases the severity of ARIE in these patients. Secondary objectives included assessment of the effects of glutamine on other measures of ARIE, weight, symptom burden measure assessed by the MD Anderson Symptom Inventory (MDASI-HN) questionnaire and the toxicity profile of glutamine. Results At the time of interim analysis, 53 patients were enrolled: 27 in the glutamine arm and 26 in the placebo arm. There was no difference in the incidence of esophagitis in the first 6 weeks of radiotherapy between the glutamine and placebo arms (74% versus 68%; P = 1.00). There were no significant differences between the two arms for time to onset of esophagitis. The duration of ARIE was shorter (6.3 versus 7.1 weeks; P = 0.54) and median weight loss was lower (0.9 kg versus 2.8 kg; p = 0.83) in the glutamine arm versus the placebo arm. The groups differ significantly in core symptom severity (2.1 vs 1.5, p < .03) but not in head and neck specific symptom severity (1.2 vs 1.1, p < .60) nor in symptom interference (2.1 vs 1.7, p < .22). There was no grade 3 or higher adverse event at least possibly related to glutamine. The study was terminated for futility following interim analysis. Conclusion Oral glutamine was not associated with significant improvement in severity of ARIE, weight loss, head and neck specific symptoms or symptom interference compared with placebo in patients with advanced thoracic malignancies receiving radiotherapy to the esophagus.Clinical trial information. NCT01952847, and date of registration is September 30, 2013.

Oral mucositis: the hidden side of cancer therapy

Inflammation response of epithelial mucosa to chemo- radiotherapy cytotoxic effects leads to mucositis, a painful side effect of antineoplastic treatments. About 40% of the patients treated with chemotherapy develop mucositis; this percentage rises to about 90% for head and neck cancer patients (HNC) treated with both chemo- and radiotherapy. 19% of the latter will be hospitalized and will experience a delay in antineoplastic treatment for high-grade mucositis management, resulting in a reduction of the quality of life, a worse prognosis and an increase in patient management costs. Currently, several interventions and prevention guidelines are available, but their effectiveness is uncertain. This review comprehensively describes mucositis, debating the impact of standard chemo-radiotherapy and targeted therapy on mucositis development and pointing out the limits and the benefits of current mucositis treatment strategies and assessment guidelines. Moreover, the review critically examines the feasibility of the existing biomarkers to predict patient risk of developing oral mucositis and their role in early diagnosis. Despite the expression levels of some proteins involved in the inflammation response, such as TNF-α or IL-1β, partially correlate with mucositis process, their presence does not exclude others mucositis-independent inflammation events. This strongly suggests the need to discover biomarkers that specifically feature mucositis process development. Non-coding RNAs might hold this potential.

Therapeutic effects of Co-Venenum Bufonis Oral Liquid on radiation-induced esophagitis in rats

To investigate the effects of Co-Venenum Bufonis Oral Liquid (cVBOL) on radiation-induced esophagitis in rats. Irradiation (30 Gy) with X-RAD 225 x-ray was applied to induce esophagitis in 64 Wistar rats and treated by different methods. The body weight of rats either in RT group, cVBOL+RT, or EM+RT group was significantly decreased when compared with that in normal group (P<0.0001). After irradiation, histopathological studies, immunohistochemistry, and MRI scanning on esophagus were performed. Serum TNF-α,IL-6 and IL-10 were also determined by ELISA at 7, 14, 21 and 28 days after radiation treatment. The results demonstrated that radiation caused esophageal injury and thickening of esophageal tissue layers. The esophageal tissues after radiation treatment showed typical pathological changes of esophagitis. Radiation also caused esophagus edema. Treatment of cVBOL reduced the severity of histological esophageal lesion, decreased the expression of bFGF and TGF-β1, and lowered serum levels of inflammatory cytokines including TNF-α, IL-6 and IL-10 over 28 days after radiation treatment. In conclusion, cVBOL treatment is effective to prevent radiation induced esophagitis and reduces radiation induced esophagitis may be mediated through its ant-inflammatory effects.

Effects of oral supplementation in the management of oral mucositis in cancer patients: A meta-analysis of randomized clinical trials

PURPOSE

To evaluate the effects of oral supplementation on the management of oral mucositis in patients with cancer undergoing chemo and/or radiation therapy.

METHOD

This is a systematic review and meta-analysis. The search was performed at 6 databases, and in the gray literature. Methodology of included studies was evaluated by the Cochrane Collaboration Risk of Bias Tool, and evidence quality was assessed by GRADE instrument.

RESULTS

Twelve randomized clinical trials were included in this review. The oral supplementation used was an oral elemental diet with amino acids and minerals (elental), glutamine, and zinc. The majority of the studies included in this review showed benefits in delaying the occurrence of OM by using glutamine and zinc, and in reducing the severity of OM with glutamine, zinc, and elental in patients receiving chemoradiotherapy. The meta-analysis showed that the risk of oral mucositis in the zinc group was slightly lower than in the control (RR: 0.71, 95% CI: 0.53-0.96, P = 0.02, n = 982) while the glutamine group presented the same risk as the control (RR: 0.91, 95% CI: 0.78-1.05, P = 0.19, n = 314). The evidence quality suggested low confidence for zinc and glutamine studies in the estimated effect from the outcomes assessed.

CONCLUSIONS

Zinc is a promising strategy in the management of oral mucositis since it delayed the occurrence and reduced its severity. Glutamine and Elental, on the other hand, had no strong evidence in the prevention and/or treatment of oral mucositis in patients with cancer.

Randomized double-blind, placebo-controlled trial evaluating oral glutamine on radiation-induced oral mucositis and dermatitis in head and neck cancer patients

BACKGROUND

Glutamine is the primary fuel for the gastrointestinal epithelium and maintains the mucosal structure. Oncologists frequently encounter oral mucositis, which can cause unplanned breaks in radiotherapy (RT).

OBJECTIVES

The aim of this study was to explore the association between oral glutamine and acute toxicities in patients with head and neck cancer undergoing RT.

METHODS

This was a parallel, double-blind, randomized, placebo-controlled Phase III trial conducted in a university hospital. A central randomization center used computer-generated tables to allocate interventions to 71 patients with stages I-IV head and neck cancers. The patients, care providers, and investigators were blinded to the group assignment. Eligible patients received either oral glutamine (5 g glutamine and 10 g maltodextrin) or placebo (15 g maltodextrin) 3 times daily from 7 d before RT to 14 d after RT. The primary and secondary endpoints were radiation-induced oral mucositis and neck dermatitis, respectively. These were documented in agreement with the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.

RESULTS

The study included 64 patients (placebo n = 33; glutamine n = 31) who completed RT for the completers' analysis. Based on multivariate analysis, glutamine had no significant effect on the severity of oral mucositis (OR: 0.3; 95% CI: 0.05, 1.67; P = 0.169). Only the change in body mass index (BMI) was significant in both multivariate completers (OR: 0.41; 95% CI: 0.20, 0.84; P = 0.015) and per-protocol analysis (OR: 0.40; 95% CI: 0.20, 0.83; P = 0.014). No difference was found in the incidence and severity of neck dermatitis between the two arms.

CONCLUSIONS

The decrease in BMI was strongly related to the severity of oral mucositis in the head and neck cancer patients under RT, but not to the use of glutamine. This trial was registered at clinicaltrials.gov as NCT03015077.

Adjunctive Treatments for the Prevention of Chemotherapy- and Radiotherapy-Induced Mucositis

Background: Chemoradiotherapy-associated mucositis can manifest as pain, inflammation, dysphagia, diarrhea, weight loss, rectal bleeding, and infection. Mucositis is a major dose-limiting side effect of chemotherapy, affecting nutritional intake and oral and intestinal function. Despite several interventions being available, there is a need for safe and effective preventative and treatment options for treatment-induced mucositis. The goals of this review are to discuss interventions based on foods and natural products and present the research to date. Methods: A narrative literature review identified 60 clinical studies examining various nutritional compounds and 20 examining probiotics. 9 studies on probiotics for the prevention of diarrhea were also assessed on methodological quality and limitations identified. Results: Several compounds have been posited as useful adjuvants for cancer treatment–related mucositis. Probiotics demonstrate efficacy for the prevention and treatment of chemoradiotherapy-induced gastrointestinal toxicity without significant side effects. Glutamine and activated charcoal were reported to reduce chemotherapy-induced diarrhea but not radiation-induced intestinal mucositis. Honey has been reported to decrease treatment interruptions, weight loss, and delays the onset of oral mucositis. Zinc, glutamine, and topical vitamin E were demonstrated efficacy for oral mucositis. Conclusion: There is plausible clinical evidence for the administration of several adjunctive treatments for the prevention and treatment of mucositis. Probiotics were reported to reduce the burden of intestinal mucositis and treatment-induced diarrhea. Activated charcoal and glutamine are beneficial for chemotherapy-induced diarrhea, whereas the administration of honey, zinc, and glutamine reduce the risk of developing oral mucositis during chemotherapy or radiotherapy.

Efficacy of a Propolis-Based Syrup (FARINGEL) in Preventing Radiation-Induced Esophagitis in Locally Advanced Lung Cancer

AIM

To evaluate the efficacy of a propolis-based syrup, FARINGEL®, in preventing radiation-induced esophagitis in locally advanced lung cancer patients.

METHODS

Patients were treated with concurrent chemoradiotherapy (CRT) using involved-field radiotherapy (RT). Every patient received FARINGEL at the beginning of CRT until the first follow-up. The data of the study group were compared with the data of a control group treated without the administration of the syrup.

RESULTS

Forty-five patients were enrolled. Forty-one (91.1%) completed the protocol and were evaluable for esophagitis. Grade ≥2 toxicity occurred in 9/41 patients (22%). No differences in overall toxicity were detected between the study group and the control group (n = 55, 60.9 vs. 54.5%; p = ns). Grade 2-3 esophagitis was lower in the study group in comparison with the control group (22 and 38%, respectively), but statistical significance was not reached (p = 0.09). However, the onset of grade ≥2 esophagitis was delayed in the study group compared to the control group, occurring at higher doses of RT (41.8 vs. 25.4 Gy; p < 0.001). Furthermore, the mean number of interruption days for esophagitis was lower in the study group than in the control group (0.6 ± 2.0 vs. 2.1 ± 3.6; p = 0.025).

CONCLUSION

FARINGEL was well-tolerated and delayed esophagitis that was induced by CRT for locally advanced lung cancer.

Double-blind randomized study of oral glutamine on the management of radio/chemotherapy-induced mucositis and dermatitis in head and neck cancer

This randomized clinical trial was designed to determine whether glutamine administration was effective in reducing the incidence and severity of mucositis and dermatitis induced by radiotherapy (RT) or chemoradiotherapy (CHRT) in patients with head and neck cancer (HNC). Fifty patients were randomized to receive orally either L-Glutamine or placebo (25 patients in each arm). In the glutamine-treated group, 10 g of oral glutamine was administered three times daily. The primary endpoint was to compare the appearance of clinical mucositis between groups at the 6th week, according to the Common Terminology Criteria for Adverse Events. Secondary endpoints were: Functional mucositis, mucositis onset, cervicofacial dermatitis, pain, weight loss and assessment of quality of life (according to the M.D. Anderson Symptom Inventory-Head and Neck). In total, 76 and 87.5% developed clinical mucositis in the glutamine and placebo group, respectively. The incidence and severity grade of mucositis at the 6th week did not exhibit statistically significantly differences between the two groups, although it had a higher value in the placebo group. Significant reduction of dermatitis incidence (P=0.038) and severity (P=0.032) was found in the glutamine group. There were no differences in other outcomes such as pain, weight loss and mucositis onset, in treatment parameters including concomitant chemotherapy, radiation dose and previous surgery, or in quality of life. The present study revealed that glutamine provided slight clinical effects compared with placebo in terms of reducing oral mucositis induced by RT or CHRT in patients with HNC at the 6th week; however, the results were not statistically significant. Although the findings suggested a significant benefit in reducing the incidence and severity of dermatitis, further confirmatory studies are required.

Radiation-induced esophagitis in lung cancer

Radiation-induced esophagitis is the most common local acute toxicity of radiotherapy (RT) delivered for the curative or palliative intent treatment of lung cancer. Although concurrent chemotherapy and higher RT dose are associated with increased esophagitis risk, advancements in RT techniques as well as adherence to esophageal dosimetric constraints may reduce the incidence and severity. Mild acute esophagitis symptoms are generally self-limited, and supportive management options include analgesics, acid suppression, diet modification, treatment for candidiasis, and maintenance of adequate nutrition. Esophageal stricture is the most common late sequela from esophageal irradiation and can be addressed with endoscopic dilatation. Approaches to prevent or mitigate these toxicities are also discussed.

Glutamine in Alleviation of Radiation-Induced Severe Oral Mucositis: A Meta-Analysis

The aim of this meta-analysis was to assess the effectiveness of glutamine to treat severe mucositis induced by radiation therapy in patients with head and neck cancer. We undertook electronic searches of PubMed (1990 to January 2015), Embase (1990 to January 2015), and the Cochrane Library (2013, Issue 2) to identify relevant studies. We included randomized controlled trials of glutamine to alleviate oral mucositis (OM) in patients with head and neck cancer who received radiotherapy. Information regarding methods, patients, results, and risk of bias was independently extracted by two authors. Statistical analyses were conducted to calculate the odds ratio and 95% confidence intervals (95%CIs) using fixed-effect models. We identified five clinical studies that included 234 patients with head and neck cancer. All studies were assessed as being at low risk of bias in most items of six domains. In this meta-analysis, glutamine treatment showed a statistically significant benefit with respect to reducing the risk and severity of OM induced by radiotherapy compared to either placebo or no treatment (risk ratio 0.17, 95%CI 0.06-0.47). Overall, glutamine significantly reduces the risk and severity of OM during radiotherapy or chemotherapy. Further prospective and large trials are required to support the findings.

Radiation-Induced Esophagitis In Vivo and In Vitro Reveals That Epidermal Growth Factor Is a Potential Candidate for Therapeutic Intervention Strategy

PURPOSE

To establish and characterize radiation-induced esophagitis (RIE) in vivo and in vitro.

METHODS AND MATERIALS

Fractionated thoracic irradiation at 0, 8, 12, or 15 Gy was given daily for 5 days to Balb/c or C57Bl/6 mice. Changes in body weight gain and daily food intake were assessed. At the end of the study, we removed the esophagus and examined histology by hematoxylin and eosin staining, immune cell infiltration and apoptosis by fluorescence-activated cell sorting, and gene expression changes by quantitative real-time polymerase chain reaction. Het-1A human esophageal epithelial cells were irradiated at 6 Gy, treated with recombinant human growth factors, and examined for gene expression changes, apoptosis, proliferation, and signal transduction pathways.

RESULTS

We observed that irradiation at 12 Gy or 15 Gy per fraction produced significant reduction in body weight and decreased food intake in Balb/c mice but not as much in C57Bl/6 mice. Further analyses of Balb/c mice irradiated at 12 Gy/fraction revealed attenuated epithelium, inflamed mucosa, and increased numbers of infiltrating CD4+ helper T cells and apoptotic cells. Moreover, we found that expression of tissue inhibitor for metalloproteinase-1, plasminogen activator inhibitor-1, granulocyte macrophage-colony stimulating factor, vascular endothelial growth factor, and stromal-derived factor-1 were increased, whereas epidermal growth factor (EGF) was decreased. Irradiated Het-1A cells similarly showed a significant decrease in expression of EGF and connective tissue growth factor (CTGF). Treatment of EGF but not CTGF partially protected Het-1A cells from radiation-induced apoptosis and revealed phosphorylation of EGFR, AKT, and ERK signaling pathways.

CONCLUSIONS

We established a mouse model of RIE in Balb/c mice with 12 Gy × 5 fractions, which showed reduced body weight gain, food intake, and histopathologic features similar to those of human esophagitis. Decreased EGF expression in the irradiated esophagus suggests that EGF may be a potential therapeutic intervention strategy to treat RIE.

The role of glutamine supplementation in thoracic and upper aerodigestive malignancies

In cancer patients, marked glutamine (gln) depletion develops over time. Host tissues (epithelial cells and lymphocytes) that depend upon adequate stores of gln for optimal functioning can be negatively influenced. In addition, radiation and/or chemotherapy cause normal tissues damage that might be enhanced by this depletion effect. The present review evaluates in vivo clinical data about the potential beneficial role of gln administration in the prevention of host tissue toxicity, in a patient group with thoracic and upper aerodigestive malignancies (T&UAM) during cancer treatment. Publications were identified in a systematic review of MEDLINE Database from the last 2 decades (1994-2014) using key search terms and through manual searches. Overall, 13 clinical studies (9 oral/4 parenteral) evaluated the safety and tolerance of gln supply, showing a beneficial effect in the grade, duration of mucositis and esophagitis, decreased gut permeability, and weight loss. Only 1 Phase 1 clinical trial had negative results because the chemo-radiotherapy combined treatment was not feasible. The use of oral gln may especially have an important role in the prevention of acute radiation toxicities, the weight loss and the need for analgesics in patients with T&UAM, especially if the treatment plan includes combined modality therapy with chemo-radiation.