The effects of enteral glutamine on radiotherapy induced dermatitis in breast cancer

Effectiveness of glutamine for the treatment of radiodermatitis in cancer patients: a meta-analysis of randomized controlled trials

BACKGROUND

After receiving radiation therapy, 60%-95% of patients with cancer develop radiodermatitis, which causes pain, wound infection, and poor quality of life. Glutamine is a popular nutritional supplement for patients with cancer. Several studies examined the usefulness of glutamine for reducing radiodermatitis. However, there is still no consolidated evidence for clinical use.

METHODS

We searched PubMed, Embase, Cochrane Library, CINAHL PLUS, and the China Knowledge Resource Integrated Database for the relevant literature published up to March 2023, without language restrictions. Two reviewers screened, filtered, and appraised these articles independently, and their data were pooled using a random-effects model.

RESULTS

Five randomized controlled trials (RCTs) with 218 participants were analyzed. The incidence of radiodermatitis in the glutamine group (89/110) was significantly lower than in the placebo group (99/108; risk ratio [RR], 0.90; 95% CI, 0.81-1.00; p = 0.05; I2 = 7%). The incidence of moderate to severe radiodermatitis was significantly lower in the glutamine group than in the placebo group (RR, 0.49; 95% CI, 0.32-0.76; p = 0.001; I2 = 52%). Moreover, subgroup analysis demonstrated heterogeneity (I2 = 52%) for moderate to severe radiodermatitis, the risk of which might be significantly reduced by a glutamine dose of 20-30 g/day (RR, 0.60; 95% CI, 0.41-0.87; I2 = 0%).

CONCLUSION

The meta-analysis indicate that glutamine might lead to a lower incidence of radiodermatitis, and that a glutamine dose of 20-30 g/day might decrease the incidence of moderate to severe dermatitis. Thus, the serious impact of radiodermatitis on treatment follow-up makes the clinical use of glutamine even more important. PROSPERO number: CRD42021254394.

Oral glutamine: Is there a role in the amelioration of radiation-induced mucositis? A prospective case-control study at a tertiary care centre in North India

BACKGROUND

The most frequently occurring painful and dose-limiting side effect of radiation therapy (RT) to the head and neck region is oral mucositis (OM). Several studies demonstrated that glutamine may reduce the severity and the duration of OM significantly during RT and chemo-radiotherapy in patients with head and neck cancer (HNC).

MATERIALS AND METHODS

Between January 2021 and August 2022, a prospective single institutional case-control study compared the efficacy and safety of oral glutamine on radiation-induced mucositis in patients with HNC. Of 60 biopsy-proven patients with HNC, 30 patients in the study arm received oral glutamine suspension (10 g in 500 mL of water) orally once daily, 2 hours before RT, receiving definitive or adjuvant RT and chemo-radiotherapy, while as 30 patients in the control arm received placebo with the same dose and schedule (n = 30 in the study arm and n = 30 in the control arm).

RESULTS AND ANALYSIS

A total of 27 (90%) in the glutamine arm and 28 (93.33%) patients in the control arm developed mucositis. Grade 3 mucositis (13.33%) and Grade 4 mucositis (6.66%), respectively, were significantly less (P = .040 and P = .004) in the glutamine arm. The mean duration of grade 3 and grade 4 mucositis was significantly less in the glutamine arm (8.94 days in the study arm vs. 14.54 in the control arm; P = .0001). The mean time of onset of OM was significantly delayed in the glutamine arm in comparison to the control arm with P < .001.

CONCLUSION

Glutamine delays the onset of OM and decreases the severity of OM in patients of HNC receiving RT with or without chemotherapy.

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.

Therapeutic Efficacy, Radiotoxicity and Abscopal Effect of BNCT at the RA-3 Nuclear Reactor Employing Oligo-Fucoidan and Glutamine as Adjuvants in an Ectopic Colon Cancer Model in Rats

Boron neutron capture therapy (BNCT) is based on the preferential uptake of ¹⁰B compounds by tumors, followed by neutron irradiation. The aim of this study was to assess, in an ectopic colon cancer model, the therapeutic efficacy, radiotoxicity, abscopal effect and systemic immune response associated with (BPA/Borophenylalanine+GB-10/Decahydrodecaborate)-BNCT (Comb-BNCT) alone or in combination with Oligo-Fucoidan (O-Fuco) or Glutamine (GLN), compared to the "standard" BPA-BNCT protocol usually employed in clinical trials. All treatments were carried out at the RA-3 nuclear reactor. Boron biodistribution studies showed therapeutic values above 20 ppm ¹⁰B in tumors. At 7 weeks post-treatment, the ratio of tumor volume post-/pre-BNCT was significantly smaller for all BNCT groups vs. SHAM (p < 0.05). The parameter "incidence of tumors that underwent a reduction to ≤50% of initial tumor volume" exhibited values of 62% for Comb-BNCT alone, 82% for Comb-BNCT+GLN, 73% for Comb-BNCT+O-Fuco and only 30% for BPA-BNCT. For BPA-BNCT, the incidence of severe dermatitis was 100%, whereas it was significantly below 70% (p ≤ 0.05) for Comb-BNCT, Comb-BNCT+O-Fuco and Comb-BNCT+GLN. Considering tumors outside the treatment area, 77% of Comb-BNCT animals had a tumor volume lower than 50 mm³ vs. 30% for SHAM (p ≤ 0.005), suggesting an abscopal effect of Comb-BNCT. Inhibition of metastatic spread to lymph nodes was observed in all Comb-BNCT groups. Considering systemic aspects, CD8⁺ was elevated for Comb-BNCT+GLN vs. SHAM (p ≤ 0.01), and NK was elevated for Comb-BNCT vs. SHAM (p ≤ 0.05). Comb-BNCT improved therapeutic efficacy and reduced radiotoxicity compared to BPA-BNCT and induced an immune response and an abscopal effect.

Effects of oral supplementation to manage radiation dermatitis in cancer patients: a systematic review

PURPOSE

To evaluate the effectiveness and safety of oral supplementation as a radioprotective intervention in the management of radiation dermatitis (RD).

METHODS

Systematic review and meta-analysis. Six databases and the gray literature were searched for randomized controlled clinical trials (RCTs). Meta-analysis was performed only with studies that evaluated the same intervention. Methodology of included studies was evaluated by the Cochrane risk-of-bias tool for randomized trials (RoB 2.0), and the certainty of evidence was assessed by the GRADE instrument.

RESULTS

Seventeen RCTs were included in this review. These evaluated different types of oral supplementations. Findings from three meta-analyses demonstrated no significant benefits to the more severe grades of RD, as oral curcuminoids (RR, 0.59; 95% CI, 0.27 to 1.29; P = 0.19; I² = 88%), glutamine (RR, 0.40; 95% CI, 0.15 to 1.03; P = 0.06; I² = 78%) or Wobe-Mugos (RR, 0.57; 95% CI, 0.29 to 1.14; P = 0.11; I² = 72%). Also, the certainty of the evidence of outcomes evaluated was moderate or low. Except for a few gastrointestinal adverse events, oral supplementation was well tolerated.

CONCLUSION

Most oral supplements cannot yet be recommended to manage RD due to insufficient or conflicting evidence. However, despite no significant results, glutamine was shown to be a promising substance in terms of the potential radioprotective effect and may be well tolerated. These results suggest that more RCTs with larger samples are needed to evaluate the efficacy, safety, and tolerance of glutamine in the management of RD.

Dermatologic toxicities associated with radiation therapy in women with breast cancer

Breast-conserving surgery with adjuvant radiation therapy has become the standard of care for women with early stage breast cancer, and as a result, a large number of patients are affected by the cutaneous sequelae of radiation therapy. These dermatologic toxicities may present during treatment or years later and can significantly impact patients’ quality of life. In this review, we discuss the clinical presentation, prevention, and management of radiation-induced cutaneous toxicities in women with breast cancer, including radiation dermatitis, radiation recall, radiation-induced morphea, radiation-induced fibrosis, and cutaneous malignancies in irradiated skin.

Oral Glutamine May Have No Clinical Benefits to Prevent Radiation-Induced Oral Mucositis in Adult Patients With Head and Neck Cancer: A Meta-Analysis of Randomized Controlled Trials

Objectives: The role of oral glutamine for the management of oral mucositis (OM) has not yet been confirmed. The objective of the present study is to further investigate whether oral glutamine is effective in preventing and treating OM among patients with head and neck cancer (HNC) receiving radiotherapy alone or concurrent with chemotherapy.

Methods: A systematic search was performed in PubMed, EMBASE, EBSCO, and Cochrane Central Register of Controlled Trials (CENTRAL) to capture all potential citations from the inception to June 2019. Then data extraction and assessment of risk of bias were carried out after selecting the eligible citations. RevMan 5.3 software was used to perform all statistical analyses.

Results: Six randomized controlled trials (RCTs) including 441 patients were included in the final analysis. The meta-analysis showed that oral glutamine couldn't significantly decrease the incidence of OM (risk ratio [RR] = 0.98, 95% confidence interval [CI] = 0.94−1.02) and alleviate the development of moderate or severe grade of OM (Moderate-to-severe OM: RR = 0.81, 95% CI = 0.59−1.12; Severe OM: RR = 0.45, 95% CI = 0.13−1.52). But oral glutamine may have the potential to reduce the opioid use (RR = 0.84, 95% CI = 0.71−0.99). The role of oral glutamine in delaying the onset of OM remains uncertain due to conflicting results between quantitative (mean difference [MD] = 4.11 days, 95% CI = 3.49−4.73) and qualitative results.

Conclusions: Oral glutamine may have no clinical benefits to prevent or reduce the incidence and severity of radiation-induced OM in patients with HNC receiving radiotherapy alone or concurrent with chemotherapy. It is also uncertain whether oral glutamine can delay the onset of OM. But it may have the potential to relieve the degree of oral pain. Nevertheless, we must cautiously interpret the results because the observed effect size for delay in mucositis start or reduction in opioid use is marginal. Moreover, further RCTs with more rigorous methodology and large-scale are required to enhance the quality of evidence.

Glutamine Metabolism Is Essential for Stemness of Bone Marrow Mesenchymal Stem Cells and Bone Homeostasis

Skeleton has emerged as an endocrine organ which is both capable of regulating energy metabolism and being a target for it. Glutamine is the most bountiful and flexible amino acid in the body which provides adenosine 5′-triphosphate (ATP) demands for cells. Emerging evidences support that glutamine which acts as the second metabolic regulator after glucose exerts crucial roles in bone homeostasis at cellular level, including the lineage allocation and proliferation of bone mesenchymal stem cells (BMSCs), the matrix mineralization of osteoblasts, and the biosynthesis in chondrocytes. The integrated mechanism consisting of WNT, mammalian target of rapamycin (mTOR), and reactive oxygen species (ROS) signaling pathway in a glutamine-dependent pattern is responsible to regulate the complex intrinsic biological process, despite more extensive molecules are deserved to be elucidated in glutamine metabolism further. Indeed, dysfunctional glutamine metabolism enhances the development of degenerative bone diseases, such as osteoporosis and osteoarthritis, and glutamine or glutamine progenitor supplementation can partially restore bone defects which may promote treatment of bone diseases, although the mechanisms are not quite clear. In this review, we will summarize and update the latest research findings and clinical trials on the crucial regulatory roles of glutamine metabolism in BMSCs and BMSC-derived bone cells, also followed with the osteoclasts which are important in bone resorption.

Effects Of Oral Glutamine on Inflammatory and Autophagy Responses in Cancer Patients Treated With Abdominal Radiotherapy: A Pilot Randomized Trial

Background and Aims: Abdominal radiotherapy (RT) causes harm to the mid gastrointestinal mucosa by release of pro-inflammatory cytokines and promotes autophagic changes in tumor cells. This study was aimed to measure the effect of glutamine administration on markers of inflammation and autophagy in cancer patients treated with RT. Methods: In this double-blind, randomized, controlled pilot trial 43 patients under abdominal RT diagnosed of pelvic or abdominal malignancies receiving glutamine (30 g/d) or placebo (casein, 30 g/d). Patient recruitment took place in the Complejo Asistencial Universitario of León (CAULE), Spain. Patient evaluation took place at three different time points during the study: before RT (pre-treatment), in the middle of the RT period (mid-treatment), and after finishing RT (post-treatment). Data were compared by analysis of variance and the Newmann Keuls test. Significance was accepted at p < 0.05. Results Abdominal RT increased whole blood mRNA levels of inflammatory and autophagic markers, but glutamine administration showed significantly lower expression of toll-like receptor 4 (TLR4), CD36, interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), cyclooxygenase-2 (COX-2), and matrix metalloproteinase-9 (MMP-9). Moreover, glutamine reduced the expression of the transcription factors nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1). Glutamine also inhibited the autophagic response, with changes in expression of beclin-1, UV radiation resistance associated gene (UVRAG), autophagy-related protein-5 (Atg5), protein 1 light chain 3 (LC3), sequestosome 1 (p62/SQSTM1) and lysosome-associated membrane protein (LAMP)-1. Conclusions Findings provide evidence that glutamine decreases the inflammatory response and abolishes the changes of the autophagy machinery in patients receiving abdominal RT. The protective effect of glutamine must continue being investigated to disclose further molecular pathways.

ESPEN guidelines on nutrition in cancer patients

Cancers are among the leading causes of morbidity and mortality worldwide, and the number of new cases is expected to rise significantly over the next decades. At the same time, all types of cancer treatment, such as surgery, radiation therapy, and pharmacological therapies are improving in sophistication, precision and in the power to target specific characteristics of individual cancers. Thus, while many cancers may still not be cured they may be converted to chronic diseases. All of these treatments, however, are impeded or precluded by the frequent development of malnutrition and metabolic derangements in cancer patients, induced by the tumor or by its treatment. These evidence-based guidelines were developed to translate current best evidence and expert opinion into recommendations for multi-disciplinary teams responsible for identification, prevention, and treatment of reversible elements of malnutrition in adult cancer patients. The guidelines were commissioned and financially supported by ESPEN and by the European Partnership for Action Against Cancer (EPAAC), an EU level initiative. Members of the guideline group were selected by ESPEN to include a range of professions and fields of expertise. We searched for meta-analyses, systematic reviews and comparative studies based on clinical questions according to the PICO format. The evidence was evaluated and merged to develop clinical recommendations using the GRADE method. Due to the deficits in the available evidence, relevant still open questions were listed and should be addressed by future studies. Malnutrition and a loss of muscle mass are frequent in cancer patients and have a negative effect on clinical outcome. They may be driven by inadequate food intake, decreased physical activity and catabolic metabolic derangements. To screen for, prevent, assess in detail, monitor and treat malnutrition standard operating procedures, responsibilities and a quality control process should be established at each institution involved in treating cancer patients. All cancer patients should be screened regularly for the risk or the presence of malnutrition. In all patients - with the exception of end of life care - energy and substrate requirements should be met by offering in a step-wise manner nutritional interventions from counseling to parenteral nutrition. However, benefits and risks of nutritional interventions have to be balanced with special consideration in patients with advanced disease. Nutritional care should always be accompanied by exercise training. To counter malnutrition in patients with advanced cancer there are few pharmacological agents and pharmaconutrients with only limited effects. Cancer survivors should engage in regular physical activity and adopt a prudent diet.

Protection against Radiotherapy-Induced Toxicity

Radiation therapy is a highly utilized therapy in the treatment of malignancies with up to 60% of cancer patients receiving radiation therapy as a part of their treatment regimen. Radiation therapy does, however, cause a wide range of adverse effects that can be severe and cause permanent damage to the patient. In an attempt to minimize these effects, a small number of compounds have been identified and are in use clinically for the prevention and treatment of radiation associated toxicities. Furthermore, there are a number of emerging therapies being developed for use as agents that protect against radiation-induced toxicities. The aim of this review was to evaluate and summarise the evidence that exists for both the known radioprotectant agents and the agents that show promise as future radioprotectant agents.