Xerostomia induced by radiotherapy: an overview of the physiopathology, clinical evidence, and management of the oral damage

The effect of hyperbaric oxygen therapy in head and neck cancer patients with radiation induced dysphagia-a systematic review

PURPOSE

The aim of this systematic review was to assess the role of hyperbaric oxygen therapy  (HBOT) in patients with dysphagia after radiation therapy for head and neck cancer.

METHOD

A systematic search was conducted in the electronic databases Ovid MEDLINE, Ovid Embase, and Cochrane Central Register of Controlled Trials for relevant studies until March 14, 2023. No restriction on language or publication date. The criteria for inclusion: patients with HNC who had received both radiation therapy and HBOT as 1) a preventive treatment against swallowing difficulties, 2) to preserve swallowing function, or 3) to promote swallowing difficulties.

RESULTS

We identified 1396 records. After removal of 31 duplicates, 1365 records were accessible for title and abstract screening. This yielded 53 studies for full text assessment. Six studies met the eligibility criteria and were included for qualitative analysis.

CONCLUSION

Evidence of HBOT benefits in patients with dysphagia after radiation therapy for head and neck cancer is inconsistent. Well-designed studies using validated outcome measures and long-term follow-up are warranted.

Cancer therapy-related salivary dysfunction

Salivary gland dysfunction is a common side effect of cancer treatments. Salivary function plays key roles in critical daily activities. Consequently, changes in salivary function can profoundly impair quality of life for cancer patients. We discuss salivary gland anatomy and physiology to understand how anticancer therapies such as chemotherapy, bone marrow transplantation, immunotherapy, and radiation therapy impair salivary function. We discuss approaches to quantify xerostomia in the clinic, including the advantages and limitations of validated quality-of-life instruments and approaches to directly measuring salivary function. Current and emerging approaches to treat cancer therapy-induced dry mouth are presented using radiation-induced salivary dysfunction as a model. Limitations of current sialagogues and salivary analogues are presented. Emerging approaches, including cellular and gene therapy and novel pharmacologic approaches, are described.

A comprehensive analysis of the tubarial glands

The tubarial glands (TGs) are a collection of salivary glands (SGs) located within the nasopharynx, proximal to the eustachian tube. Currently, there is no quantitative characterization of the TGs. We investigated the histological architecture of the TGs and compared it with the major and minor SGs for categorization. Tubarial, parotid, submandibular, sublingual, buccal, labial, and lingual glands were excised from human donors (8 male and 3 female). Hematoxylin and eosin-stained tissue sections were analyzed to measure the area of the largest lobule, number of ducts, number of mucinous acini, and mean mucinous acini area. Based on our observation, the TGs' histology resembles the minor SGs, while having some unique characteristics that distinguish them from both major and minor SGs. The area of the largest lobule in the TGs and minor SGs was smaller than the major SGs. TGs have a lower number of ducts than the major and minor SGs. TGs contain densely packed clusters of predominantly mucinous acini surrounded by loose connective tissue resembling minor SGs. This density may explain their previously observed high prostate-specific membrane antigen uptake. In our cohort of donors, sex-based differences were observed in the mean mucinous acini area between male and female TGs, submandibular and sublingual glands. Taken together, our findings suggest the histological characteristics of all SGs are better organized on a spectrum rather than discrete groups (major vs. minor) and provide information to open new avenues for research into the TGs' role in head and neck pathologies and sexual dimorphism of the SGs.

A new approach to prevent radiation-induced xerostomia using intraglandular injection of mitochondria-boosting agents

Radiotherapy in patients with head and neck cancer fairly leads to xerostomia, profoundly affecting their quality of life. With limited effective preventive and therapeutic methods, attention has turned to exploring alternatives. This article outlines how intraglandular injection of mitochondria-boosting agents can serve as a potential strategy to reduce salivary acinar damage. This method can contribute to the thoughtful development of study protocols or medications to reduce radiation-induced salivary glands damage.

Chronic Phenotypes Underlying Radiation-Induced Salivary Gland Dysfunction

Head and neck cancer (HNC) is the sixth most diagnosed cancer, and treatment typically consists of surgical removal of the tumor followed by ionizing radiation (IR). While excellent at controlling tumor growth, IR often damages salivary glands due to their proximity to common tumor sites. Radiation damage to salivary glands results in loss of secretory function, causing severe and chronic reductions in salivary flow. This leads to the patient-reported sensation of dry mouth, termed xerostomia, which significantly reduces quality of life for HNC patients and survivors. The mechanisms underlying salivary gland damage remain elusive, and therefore, treatment options are scarce. Available therapies provide temporary symptom relief, but there is no standard of care for permanent restoration of function. There is a significant gap in understanding the chronic mechanistic responses to radiation as well as treatments that can be given in the months to years following cessation of treatment. HNC cases are steadily rising; particularly, the number of young patients diagnosed with nonfatal human papillomavirus + HNC continues to increase. The growing number of HNC diagnoses and improved prognoses results in more people living with xerostomia, which highlights the mounting need for restorative treatments. Mechanisms underlying chronic damage include decreases in acinar differentiation markers, increases in acinar cell proliferation, immune and inflammatory dysregulation, and metabolic changes including increases in amino acids and reductions in glycolysis and oxidative phosphorylation, fibrosis, and dysregulated neuronal responses. Currently, promising treatment options include adenoviral gene transfers and stem cell therapy. Thus, this review describes in depth known mechanisms contributing to chronic damage and discusses therapeutic advances in treating chronically damaged glands. Understanding the chronic response to radiation offers potential in development of new therapeutics to reverse salivary gland damage and improve the quality of life of HNC survivors.

Oral Candida in post-radiotherapy patients with xerostomia/hyposalivation: A narrative review

OBJECTIVE

Head and Neck Cancer (HNC) patients receiving radiotherapy (RT) often suffer from xerostomia and/or hyposalivation. As saliva plays an important antimicrobial and cleansing roles, these patients are at higher risks of opportunistic infections. This narrative review aims to provide an overview of current evidence on oral Candida colonisation and infection in these patients.

METHODS

A literature review of clinical studies on oral Candida colonisation and candidiasis in HNC patients receiving radiotherapy/chemoradiotherapy was conducted.

RESULTS

Many clinical studies found high levels of Candida colonisation and a substantial proportion of post-RT HNC patients suffering from oropharyngeal candidiasis (OPC). Importantly, oral Candida could be a reservoir for life-threatening systemic infection in immunocompromised patients. The rising prevalence of non-albicans Candida species and drug-resistant infections has made identification of Candida species and antifungal susceptibility more important. Recent advances in oral microbiome and its interactions with Candida are discussed. This review also offers perspectives on limitations of current evidence and suggestions for future research.

CONCLUSION

Further research to better understand Candida carriage, microbiome, OPC, and xerostomia/hyposalivation post-RT would aid in devising a more comprehensive long-term management plan and novel therapeutic approaches for HNC patients to achieve the full benefits of RT while minimising side effects.

Longitudinal study of the role of salivary proteins on radiation-related caries onset in head and neck cancer patients using 5000 ppm fluoride dentifrice up to one-year post-intensity modulated radiotherapy

OBJECTIVES

Longitudinal assessment of the role of specific proteins on radiotherapy caries (RC) onset in head and neck cancer patients(HNC) up to one-year post-IMRT using a 5000ppm fluoride paste daily.

MATERIALS AND METHODS

Dental status/salivary protein data were obtained from 40 HNC patients pre-IMRT, six months (T1) and 12 months (T2) post-IMRT (ethical approval/consent). DMFT/salivary parameters were quantified, including flow rate, mucin 5B/7, Immunoglobulin A (IgA), cystatin S and α-amylase.

RESULTS

45% patients had at least one carious lesion at T2, a significant reduction in the number of remaining teeth (65% <21), salivary flow rate (< 50%) and, protein secretion (< 0.05) post-IMRT. T1 IgA concentration/secretion rate was associated with RC (p < 0.05). Finally, IgA and total protein concentration obtained at T1 could provide a predictive pattern (AUC 82.3%) for the patients more predisposed to developing RC at T2.

CONCLUSIONS

This study demonstrated the significant association of RC with salivary proteins in HNC patients treated with IMRT, revealing the potential role of salivary proteins in the early diagnosis of RC.

CLINICAL RELEVANCE

This research contributes to revealing salivary proteins association with RC, and its role in early diagnosis. Therefore, this could be the first step towards personalized medicine approaches to improve this group quality-of-life.

Proton FLASH Radiotherapy Ameliorates Radiation-induced Salivary Gland Dysfunction and Oral Mucositis and Increases Survival in a Mouse Model of Head and Neck Cancer

Head and neck cancer radiotherapy often damages salivary glands and oral mucosa, severely negatively impacting patients' quality of life. The ability of FLASH proton radiotherapy (F-PRT) to decrease normal tissue toxicity while maintaining tumor control compared with standard proton radiotherapy (S-PRT) has been previously demonstrated for several tissues. However, its potential in ameliorating radiation-induced salivary gland dysfunction and oral mucositis and controlling orthotopic head and neck tumor growth has not been reported. The head and neck area of C57BL/6 mice was irradiated with a single dose of radiotherapy (ranging from 14-18 Gy) or a fractionated dose of 8 Gy × 3 of F-PRT (128 Gy/second) or S-PRT (0.95 Gy/second). Following irradiation, the mice were studied for radiation-induced xerostomia by measuring their salivary flow. Oral mucositis was analyzed by histopathologic examination. To determine the ability of F-PRT to control orthotopic head and neck tumors, tongue tumors were generated in the mice and then irradiated with either F-PRT or S-PRT. Mice treated with either a single dose or fractionated dose of F-PRT showed significantly improved survival than those irradiated with S-PRT. F-PRT-treated mice showed improvement in their salivary flow. S-PRT-irradiated mice demonstrated increased fibrosis in their tongue epithelium. F-PRT significantly increased the overall survival of the mice with orthotopic tumors compared with the S-PRT-treated mice. The demonstration that F-PRT decreases radiation-induced normal tissue toxicity without compromising tumor control, suggests that this modality could be useful for the clinical management of patients with head and neck cancer.

Bioengineered Salivary Gland Microtissues─A Review of 3D Cellular Models and their Applications

Salivary glands (SGs) play a vital role in maintaining oral health through the production and release of saliva. Injury to SGs can lead to gland hypofunction and a decrease in saliva secretion manifesting as xerostomia. While symptomatic treatments for xerostomia exist, effective permanent solutions are still lacking, emphasizing the need for innovative approaches. Significant progress has been made in the field of three-dimensional (3D) SG bioengineering for applications in gland regeneration. This has been achieved through a major focus on cell culture techniques, including soluble cues and biomaterial components of the 3D niche. Cells derived from both adult and embryonic SGs have highlighted key in vitro characteristics of SG 3D models. While still in its first decade of exploration, SG spheroids and organoids have so far served as crucial tools to study SG pathophysiology. This review, based on a literature search over the past decade, covers the importance of SG cell types in the realm of their isolation, sourcing, and culture conditions that modulate the 3D microenvironment. We discuss different biomaterials employed for SG culture and the current advances made in bioengineering SG models using them. The success of these 3D cellular models are further evaluated in the context of their applications in organ transplantation and in vitro disease modeling.

Mesenchymal Stem/Stromal Cell Therapy for Radiation-Induced Xerostomia in Previous Head and Neck Cancer Patients: A Phase II Randomized, Placebo-Controlled Trial

PURPOSE

No effective treatment exists for radiation-induced xerostomia. The objective of this study was to compare the effect of adipose-derived mesenchymal stem/stromal cell (ASC) injection, relative to placebo, on salivary gland function in patients with radiation-induced xerostomia.

PATIENT AND METHODS

In this single-centre, double-blind, placebo-controlled trial, patients with hyposalivation were randomised to receive ultrasound-guided injections of allogeneic ASCs or placebo into the submandibular glands. Patients were followed for 4 months. We evaluated unstimulated whole salivary flow rate (UWS), stimulated salivary flow rate, and patient-reported outcomes. Adverse events were recorded and immune response determined in blood samples.

RESULTS

We enrolled 120 patients. ASC treatment resulted in a statistically significant UWS increase of 0.04 [95% confidence interval (CI), 0.02-0.06] mL/min (38%) compared with pretreatment baseline whereas placebo treatment did not cause a significant increase [0.01 (95% CI, -0.01 to 0.04) mL/min (21%)]. Both the ASC and placebo treatment yielded notable symptom reductions, with dry mouth decreasing by 13.6 and 7.7 units, sticky saliva decreased by 14.8 and 9.3 units, swallowing difficulties decreased by 7.9 and 8.0 units, and the summary score of the Xerostomia Questionnaire decreased 5.9 and 5.1 units for the ASC and placebo arms, respectively. We found no statistically significant group difference between the ASC and placebo arms for any of the outcomes.

CONCLUSIONS

We could not confirm superiority of the ASC relative to placebo. ASC therapy significantly improved UWS in previous patients with head and neck cancer, whereas placebo resulted in an insignificant increase.

Senescence and fibrosis in salivary gland aging and disease

Salivary gland hypofunction is highly prevalent in aged and diseased individuals leading to significant discomfort and morbidity. One factor that contributes to salivary gland hypofunction is cellular aging, or senescence. Senescent cells can impair gland function by secreting paracrine-acting growth factors and cytokines, known as senescence-associated secretory phenotype (SASP) factors. These SASP factors stimulate inflammation, propagate the senescent phenotype through the bystander effect, and stimulate fibrosis. As senotherapeutics that target senescent cells have shown effectiveness in limiting disease manifestations in other conditions, there is interest in the use of these drugs to treat salivary gland hypofunction. In this review, we highlight the contribution of senescence and fibrosis to salivary gland pathologies. We also discuss therapeutic approaches to eliminate or modulate the senescent SASP phenotype for treating age-related salivary gland diseases and extending health span.

Prediction of xerostomia in elderly based on clinical characteristics and salivary flow rate with machine learning

Xerostomia may be accompanied by changes in salivary flow rate and the incidence increases in elderly. We aimed to use machine learning algorithms, to identify significant predictors for the presence of xerostomia. This study is the first to predict xerostomia with salivary flow rate in elderly based on artificial intelligence. In a cross-sectional study, 829 patients with oral discomfort were enrolled, and six features (sex, age, unstimulated and stimulated salivary flow rates (UFR and SFR, respectively), number of systemic diseases, and medication usage) were used in four machine learning algorithms to predict the presence of xerostomia. The incidence of xerostomia increased with age. The SFR was significantly higher than the UFR, and the UFR and SFR were significantly correlated. The UFR, but not SFR, decreased with age significantly. In patients more than 60 years of age, the UFR had a significantly higher predictive accuracy for xerostomia than the SFR. Using machine learning algorithms with tenfold cross-validation, the prediction accuracy increased significantly. In particular, the prediction accuracy of the multilayer perceptron (MLP) algorithm that combined UFR and SFR data was significantly better than either UFR or SFR individually. Moreover, when sex, age, number of systemic diseases, and number of medications were added to the MLP model, the prediction accuracy increased from 56 to 68%.

Efficacy of photobiomodulation therapy combined with mobile health education in patients with head and neck cancer suffering from chronic xerostomia after radiotherapy: protocol for a three-arm, randomised, placebo-controlled, double-blinded study

INTRODUCTION

The role of photobiomodulation (PBM) therapy for oral tissue damage induced by cancer treatment is currently unclear, and there is low-quality to moderate-quality evidence supporting the use of this approach for treating xerostomia and/or hyposalivation. Consequently, patients with head and neck cancer increasingly turn to basic oral hygiene to alleviate salivary gland dysfunction, and their adherence can be improved by mobile health (mHealth) education. The primary objective of this study will be to analyse the effects of different doses of PBM therapy (7.5 J/cm2 vs 3 J/cm2) plus mHealth education on quality of life (QoL), oral health, salivary secretion and salivary gland ultrasound assessment at postintervention and at the 6-month follow-up in patients with head and neck cancer after radiotherapy compared with those in control group.

METHODS AND ANALYSIS

A prospective, three-arm, randomised, placebo-controlled, double-blinded study will be conducted among patients with head and neck cancer suffering from chronic xerostomia. A total of 20 patients per arm will be included and randomly assigned to receive 7.5 J/cm2 of PBM, 3 J/cm2 of PBM or placebo therapy. PBM therapy will be applied during 24 sessions at 22 points extra and intraorally two times per week for 3 months, combined with a mobile application (https://www.laxer.es). The assessments will be recorded at the beginning of the study, at postintervention and at the 6-month follow-up. The primary outcomes will be QoL, oral health, salivary secretion and salivary gland ultrasound. The pain pressure threshold, functional performance, mood and sleep quality will be secondary indicators.

ETHICS AND DISSEMINATION

This study received ethics approval from the Andalusian Biomedical Research Ethics Portal (2402-N-21 CEIM/CEI Provincial de Granada) according to the Declaration of Helsinki for Biomedical Research. The results of this study will be presented at national and international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT05106608.

Impact of low-level laser therapy on the quality of life of patients with xerostomia undergoing head and neck radiotherapy: a systematic review

PURPOSE

To carry out a systematic review to assess whether low-level laser therapy can improve the quality of life of patients with xerostomia undergoing head and neck radiotherapy.

METHODS

A systematic search was performed through Embase, Medline/PubMed, Cochrane, Scopus, Web of Science, nonpeer-reviewed clinicaltrials.gov and LILACS. The strategy included clinical studies were selected that prospectively followed or evaluated the quality of life by directly comparing the use of low-level laser therapy for xerostomia induced by head and neck radiotherapy with alternative therapies without the use of a laser. The risk of bias in the studies was assessed by RoB 2.0 and Robins I.

RESULTS

After all application of the predetermined criteria, four studies were included, dated between the years 2014 and 2023. Three studies described as randomized clinical trials were included, one of which was a randomized pilot study and only one was a prospective clinical trial. A total of 126 patients were evaluated, all four studies used the infrared wavelength, with two studies using the combination with the red wavelength. It was observed that low-level laser therapy can change the sensation of dry mouth, improving patients' quality of life. In addition, changes related to increased stimulated and unstimulated salivary flow were also identified.

CONCLUSION

The use of low-level laser therapy has promising results on xerostomia, consequently improving the quality of life of patients undergoing radiotherapy in the head and neck region.

Plant-Derived Polyphenols to Prevent and Treat Oral Mucositis Induced by Chemo- and Radiotherapy in Head and Neck Cancers Management

Oral Mucositis (OM) is the most common side effect due to chemotherapy and radiotherapy, which are the conventional treatment options for head and neck cancers. OM is a severe inflammatory condition characterized by multifactorial etiopathogenesis. It further negatively affects patients' quality of life by severe impairment of normal oral functions. Consequently, it is mandatory to identify new effective therapeutic approaches to both prevent and treat OM while also avoiding any recurrence. Polyphenols recently attracted the interest of the scientific community due to their low toxicity and wide range of biological activities making them ideal candidates for several applications in the odontostomatological field, particularly against OM. This review collects the in vivo studies and the clinical trials conducted over the past 13 years evaluating the preventive and curative effects of several polyphenolic compounds towards chemo- and radiotherapy-induced OM, both when administered alone or as a plant-extracted phytocomplex. The literature fully confirms the usefulness of these molecules, thus opening the possibility of their clinical application. However, polyphenol limitations (e.g., unfavourable physicochemical properties and susceptibility to degradation) have emerged. Consequently, the interest of the scientific community should be focused on developing innovative delivery systems able to stabilize polyphenols, thus facilitating topical administration and maximizing their efficacy.

Sodium-hyaluronate mouthwash on radiotherapy-induced xerostomia: a randomised clinical trial

INTRODUCTION

Radiotherapy-induced xerostomia (RIX) is one of the most common adverse effects of radiotherapy (RT) in head and neck cancer patients (HNC) and a major determinant of survivors' quality of life. The primary objective was to evaluate the reduction of patients' xerostomia symptoms after the utilisation of a sodium-hyaluronate mouthwash compared to a placebo solution. The secondary objectives were to evaluate the improvement of quality of life and to evaluate the patients' satisfaction.

METHODS

The protocol was approved by the ethical committee (Ref. 50,053/19) and registered at ClinicalTrials.gov (ID: NCT05103124). The study was a double-blind randomised clinical trial (RCT) with a crossover design and was conducted at the Fondazione Policlinico Universitario A. Gemelli, Rome.

RESULTS

Thirty-two patients completed the study protocol. Lower values of the modified Xerostomia Questionnaire (XQ) were retrieved when comparing the baseline scores to the ones after the treatment, when compared with placebo (Mann-Whitney U test = 0.01); higher values of patients' satisfaction (Likert scale) and modified XQ were retrieved for the sodium-hyaluronate mouthwash (Mann-Whitney U test = 0.001).

CONCLUSIONS

This RCT highlights the advantages of treating RIX with the sodium-hyaluronate mouthwash since it seems to be clinically effective in reducing its symptoms, without any reported adverse events.

CLINICALTRIALS

gov: NCT05103124 in 17/10/2021.

[Prevention, Diagnosis, Therapy, and Follow-up of Lung Cancer - Interdisciplinary Guideline of the German Respiratory Society and the German Cancer Society - Abridged Version]

The current S3 Lung Cancer Guidelines are edited with fundamental changes to the previous edition based on the dynamic influx of information to this field:The recommendations include de novo a mandatory case presentation for all patients with lung cancer in a multidisciplinary tumor board before initiation of treatment, furthermore CT-Screening for asymptomatic patients at risk (after federal approval), recommendations for incidental lung nodule management , molecular testing of all NSCLC independent of subtypes, EGFR-mutations in resectable early stage lung cancer in relapsed or recurrent disease, adjuvant TKI-therapy in the presence of common EGFR-mutations, adjuvant consolidation treatment with checkpoint inhibitors in resected lung cancer with PD-L1 ≥ 50%, obligatory evaluation of PD-L1-status, consolidation treatment with checkpoint inhibition after radiochemotherapy in patients with PD-L1-pos. tumor, adjuvant consolidation treatment with checkpoint inhibition in patients withPD-L1 ≥ 50% stage IIIA and treatment options in PD-L1 ≥ 50% tumors independent of PD-L1status and targeted therapy and treatment option immune chemotherapy in first line SCLC patients.Based on the current dynamic status of information in this field and the turnaround time required to implement new options, a transformation to a "living guideline" was proposed.

Xerostomia: From Pharmacological Treatments to Traditional Medicine-An Overview on the Possible Clinical Management and Prevention Using Systemic Approaches

Despite high incidence rates and severe complications, the management of xerostomia lacks clinical guidelines. The aim of this overview was to summarize the clinical experience derived from the last 10 years of treatments and prevention using systemic compounds. Results showed that the cytoprotective drug amifostine, and its antioxidant agents, are the most discussed as preventive agents of xerostomia in head and neck cancer (HNC) patients. In the presence of the disease, the pharmacological treatments have been mainly directed to stimulate secretion of the damaged salivary glands, or to counteract a decreased capacity of the antioxidant system, in view of an increasing of reactive oxygen species (ROS). However, the data demonstrated low ability of the drugs, together with a great number of side effects, which strongly limit their use. Concerning traditional medicine (TM), valid clinical trials are so limited that neither the efficacy nor the absence of interferences to concomitant chemical therapies can be validated. Consequently, the management of xerostomia and its devastating complications remain a very significant void in daily clinical practice.

Cell-Free Therapies: The Use of Cell Extracts to Mitigate Irradiation-Injured Salivary Glands

Radiotherapy is a standard treatment for head and neck cancer patients worldwide. However, millions of patients who received radiotherapy consequently suffer from xerostomia because of irreversible damage to salivary glands (SGs) caused by irradiation (IR). Current treatments for IR-induced SG hypofunction only provide temporary symptom alleviation but do not repair the damaged SG, thus resulting in limited treatment efficacy. Therefore, there has recently been a growing interest in regenerative treatments, such as cell-free therapies. This review aims to summarize cell-free therapies for IR-induced SG, with a particular emphasis on utilizing diverse cell extract (CE) administrations. Cell extract is a group of heterogeneous mixtures containing multifunctional inter-cellular molecules. This review discusses the current knowledge of CE's components and efficacy. We propose optimal approaches to improve cell extract treatment from multiple perspectives (e.g., delivery routes, preparation methods, and other details regarding CE administration). In addition, the advantages and limitations of CE treatment are systematically discussed by comparing it to other cell-free (such as conditioned media and exosomes) and cell-based therapies. Although a comprehensive identification of the bioactive factors within CEs and their mechanisms of action have yet to be fully understood, we propose cell extract therapy as an effective, practical, user-friendly, and safe option to conventional therapies in IR-induced SG.

Factors for poor oral health in long-term childhood cancer survivors

BACKGROUND

Survivors of childhood cancer are at risk for therapy-related dental diseases. The purpose of the study was to investigate the associations between clinical, socioeconomic, and demographic factors and oral diseases in the St. Jude Lifetime Cohort (SJLIFE) participants.

METHODS

We performed a retrospective medical chart review and evaluated longitudinal self-reported dental outcomes in 4856 childhood cancer survivors and 591 community controls participating in the St. Jude Lifetime Cohort (SJLIFE) study. Univariate and multivariable logistic regression models were used to assess the impact of socioeconomic factors, treatment exposures and patient demographics on dental outcomes.

RESULTS

Cancer survivors were more likely to report microdontia (odds ratio (OR) = 7.89, 95% confidence interval (CI) [4.64, 14.90]), abnormal root development (OR = 6.19, CI [3.38, 13.00]), hypodontia (OR = 2.75, CI [1.83, 4.33]), enamel hypoplasia (OR = 4.24, CI [2.9, 6.49]), xerostomia (OR = 7.72, CI [3.27, 25.10]), severe gingivitis (OR = 2.04, CI [1.43, 3.03]), and ≥ 6 missing teeth (OR = 3.73, CI [2.46, 6.00]) compared to controls without cancer history. Survivors who received classic alkylating agents (OR = 1.6, CI [1.36, 1.88]), anthracycline antibiotics (OR = 1.22, CI [1.04, 1.42] or radiation therapy potentially exposing the oral cavity (OR = 1.48, CI [1.26, 1.72]) were more likely to report at least one dental health problem after controlling for socioeconomic factors, age at last follow-up and diagnosis, other treatment exposures, and access to dental services. Survivors who had radiation therapy potentially exposing the oral cavity (OR = 1.52, CI [1.25, 1.84]) were also more likely to report at least one soft tissue abnormality after controlling for socioeconomic factors, age at last follow-up and diagnosis, other treatment exposures, and access and utilization of dental services.

CONCLUSIONS

Childhood cancer survivors have a higher prevalence of oral-dental abnormalities than the controls without a cancer history. Cancer treatment, socioeconomic factors, and access to oral health care contribute to the prevalence of dental abnormalities.

Quality of Life, Psychological Distress, and Nutritional Status of Polish Patients with Head and Neck Cancer Treated with Radiotherapy

INTRODUCTION

Head and neck cancer (HNC) is a global epidemiological and clinical problem. In 2020, it was the seventh most common type of cancer worldwide. In 2019, HNC was the fourth most common cause of cancer death among men in Poland. Radiotherapy plays an important role in the treatment of patients with HNC at all clinical stages. However, it is associated with a significant rate of early and late adverse effects. As head and neck cancers are located close to vital anatomical structures, both the local progression of the disease and the treatments used can cause serious problems for patients with HNC, reducing their health-related quality of life (HRQoL) as well as increasing the risk of depressive disorders. Despite this, the current literature lacks research on these aspects of the therapeutic process in the Polish population. The aim of this study was to assess the early impact of radiotherapy on HRQoL outcomes, psychological distress, nutritional status, and overall performance of patients with HNC.

METHODS

The study was carried out among 85 patients with HNC treated in the Inpatient Radiotherapy Unit of the Radiotherapy Department of the Lower Silesian Oncology Center in Wrocław. The patients were asked to complete a set of questionnaires, including the EORTC QLQ-H&N35, the BDI, the NRS-2002, and the ECOG scale, at two time points: before the initiation of radiotherapy treatment and after a course of radiotherapy. The period between the assessments was 7 to 8 weeks.

RESULTS

Our findings demonstrated a negative impact of radiotherapy on scores in all the cancer-specific symptom and functioning scales used in the study. As regards functioning scales, the largest differences were observed for senses and swallowing, whereas with symptoms scales, the largest differences were noted for "sticky saliva" and "dry mouth". Over half of the patients included in the study required nutritional support after radiotherapy treatment. We found statistically significant differences in the levels of depressive symptom severity before and after radiotherapy treatment.

CONCLUSION

The present study showed significant changes in the physical and psychological functioning and nutritional status of the patients with HNC studied after radiotherapy treatment, which may have an impact on the effectiveness of cancer treatment.

Intraglandular mesenchymal stem cell treatment induces changes in the salivary proteome of irradiated patients

BACKGROUND

Hyposalivation and xerostomia (dry mouth), are the leading site-effects to treatment of head and neck cancer. Currently, there are no effective therapies to alleviate radiation-induced hyposalivation. Adipose tissue-derived mesenchymal stem/stromal cells (AT-MSCs) have shown potential for restoring salivary gland function. However, the mode of action is unknown. The purpose of the present study was therefore to characterize the effect of AT-MSC therapy on the salivary proteome in previously irradiated head and neck cancer patients.

METHODS

Whole saliva was collected from patients with radiation-induced salivary gland hypofunction (n = 8) at baseline, and 120 days after AT-MSC treatment, and from healthy controls (n = 10). The salivary proteome was characterized with mass spectrometry based proteomics, and data was compared within the AT-MSC group (baseline versus day 120) and between AT-MSC group and healthy controls. Significance levels between groups were determined by using double-sided t-test, and visualized by means of principal component analysis, volcano plots and cluster analysis.

RESULTS

Here we show that 140 human proteins are significantly differentially expressed in saliva from patients with radiation-induced hypofunction versus healthy controls. AT-MSC treatment induce a significant impact on the salivary proteome, as 99 proteins are differentially expressed at baseline vs. 120 days after treatment. However, AT-MSC treatment does not restore healthy conditions, as 212 proteins are significantly differentially expressed in saliva 120 days after AT-MSCs treatment, as compared to healthy controls.

CONCLUSION

The results indicate an increase in proteins related to tissue regeneration in AT-MSCs treated patients. Our study demonstrates the impact of AT-MSCs on the salivary proteome, thereby providing insight into the potential mode of action of this novel treatment approach.

Quality of Life After Total Laryngectomy: A Retrospective Study

Quality of life is severely affected in laryngeal cancer patients, who have undergone total laryngectomy, particularly with regard to cancer diagnosis and the consequences of total laryngectomy. The aim of the present study is to record and evaluate the problems related with the quality of life in laryngectomized patients. A further goal is to investigate, whether a correlation exists between demographics and clinical characteristics of the patients. Fifty male patients, who underwent total laryngectomy, participated in the study. Two questionnaires were used to test various quality of life parameters, the EORTC QLQ C30 version 3.0 and EORTC QLQ H&N35. Specific demographic and clinical data of the patients were also recorded. The overall quality of life index was similar in both studied patients and the reference group of cancer patients provided by the European Organization for Research and Treatment of Cancer (EORTC). However, the following discrepancies were noted: voice, senses, dyspnoea were more problematic in studied patients, whereas the functional status of cognitive, physical, social and emotional function were better. In most recorded symptoms, the intensity was mild. The demographic and clinical data appeared to have interesting correlations with specific functional aspects and symptoms. Although several quality of life aspects are found to be negatively affected in laryngectomized patients, overall quality of life appears to be satisfactory.

Changes in oral function, swallowing function, and quality of life in patients with head and neck cancer: a prospective cohort study

Background

Head and neck cancer (HNC) treatment can cause oral morbidities, such as oral dryness and dysphagia, affecting the patient’s quality of life (QOL). The relationship between oral functions and QOL in patients with early-stage HNC remains poorly studied. This study aimed to evaluate changes in the QOL of patients with early-stage HNC and identify factors that affect the QOL of these patients.

Methods

In this prospective cohort study, 37 patients who underwent early-stage (Stage I/Stage II) HNC treatment were evaluated for their oral function, swallowing function, and the QOL score at baseline (BL) and 12 months after surgical treatment (12 M). The participants were divided into two groups: patients who returned to the BL QOL score at 12 M (RE; n = 26) and those who did not (NR; n = 11).

Results

In total, 29.7% (11/37) patients with early-stage HNC did not return to the BL QOL score at 12 M. There was no significant difference between the RE and NR groups regarding the oral and swallowing function. Moreover, oral and swallowing function of all patients returned to the BL at 12 M. The NR group showed lower QOL scores than the RE group in the global health status, and “sticky saliva” parameters in the questionnaires.

Conclusion

Restoration of the oral function is insufficient to improve the QOL of patients with early-stage HNC. The treatment of these patients should instead consider several factors that affect their QOL.

Short-term and bystander effects of radiation on murine submandibular glands

Many patients treated for head and neck cancers experience salivary gland hypofunction due to radiation damage. Understanding the mechanisms of cellular damage induced by radiation treatment is important in order to design methods of radioprotection. In addition, it is crucial to recognize the indirect effects of irradiation and the systemic responses that may alter saliva secretion. In this study, radiation was delivered to murine submandibular glands (SMGs) bilaterally, using a 137Cs gamma ray irradiator, or unilaterally, using a small-animal radiation research platform (SARRP). Analysis at 3, 24 and 48 h showed dynamic changes in mRNA and protein expression in SMGs irradiated bilaterally. Unilateral irradiation using the SARRP caused similar changes in the irradiated SMGs, as well as significant off-target, bystander effects in the non-irradiated contralateral SMGs.

Quality of Life and Aesthetic Satisfaction in Patients Who Underwent the “Commando Operation” with Pectoralis Major Myocutaneus Flap Reconstruction—A Case Series Study

The “commando operation” is an extensive surgical procedure used to treat patients with oral squamous carcinoma and metastasis in the cervical lymph nodes. While the procedure can be curative, it is also very mutilating, which consequently has a major impact on the patient’s quality of life. Several studies showed that the procedure is associated with loss of certain functions, such as impairments in speech, chewing, swallowing, and loss of taste and appetite. Furthermore, some of these impairments and their degree depend on the reconstruction method. However, the data regarding the functional impairments and aesthetic results in patients who underwent the “commando operation” along with the pectoralis major myocutaneus flap reconstruction are still inconclusive. This study included 34 patients that underwent partial glossectomy, ipsilateral modified radical neck dissection, pectoralis major myocutaneus flap reconstruction, and adjuvant radiotherapy. A structured questionnaire was used to evaluate aesthetical results and functional impairments as well as to grade the level of satisfaction with the functional and aesthetic outcomes both by the patients and by the operator. Most of the patients stated that their speech (N = 33; 97%) and salivation (N = 32; 94.2%) severely changed after the operation and that they cannot chew (N = 33; 97%) and swallow (N = 33; 97%) the same as before the operation. Moreover, almost half of the patients (N = 16; 47%) reported that they have severe sleep impairments. However, only few of the included patients stated that they sought professional help regarding the speech (N = 4; 11.7%), eating (N = 5; 14.7%), and sleeping (N = 4; 11.7%) disturbances. Additionally, there was a statistically significant difference between the operator and the patients in the subjective assessment of the aesthetic results (p = 0.047), as operators gave significantly better grades. Our results imply that this procedure and reconstructive method possibly cause impairments that have an impact on the patients’ wellbeing. Moreover, our outcomes also suggest that patients should be educated and rehabilitated after the “commando operation” since most of them were reluctant to seek professional help regarding their impairments. Lastly, sleep deficiency, which was observed after the procedure, should be further explored.

The Quantification of Salivary Flow and pH and Stomatognathic System Rehabilitation Interference in Patients with Oral Diseases, Post-Radiotherapy

Xerostomia is a common complication post-radiotherapy in patients with oral cancer. The acute and long-term side effects can considerably reduce the patient’s quality of life. The aim of our study was to perform analysis of salivary flow and pH in patients after radiotherapy. Methodology: Clinical and laboratory evaluations were conducted in the 2014–2019 period; out of a total 58 subjects aged between 45 and 84, 28 individuals with oral cancer were selected from St. Spiridon Hospital, Clinic of Maxillo-facial Surgery and Oncology Hospital, Iasi post-radiotherapy. Results: Significant downsized mean values of the hydrogen ion concentration (pH) in saliva (p < 0.001) were recorded in patients after radiotherapy, pH value = 4.580 (±1.051). The mean value of resting salivary flow (MRSF) was significantly lower for the group of patients with radiotherapy (MRSF) = 0.145 mL/min. In 89.29% of cases (25 post-radiotherapy cases), in order to perform oral complex rehabilitation treatment, several endodontic and periodontal treatments were performed. A total of 78.57% of the cases received complex oral rehabilitation as mobile or hybrid prostheses or fixed solutions. Conclusion: Understanding post-radiotherapy salivary biochemic modifications in patients with oral cancer could be of critical importance, in view of related oral disorder prevention.

MUC1 and Polarity Markers INADL and SCRIB Identify Salivary Ductal Cells

Current treatments for xerostomia/dry mouth are palliative and largely ineffective. A permanent clinical resolution is being developed to correct hyposalivation using implanted hydrogel-encapsulated salivary human stem/progenitor cells (hS/PCs) to restore functional salivary components and increase salivary flow. Pluripotent epithelial cell populations derived from hS/PCs, representing a basal stem cell population in tissue, can differentiate along either secretory acinar or fluid-transporting ductal lineages. To develop tissue-engineered salivary gland replacement tissues, it is critical to reliably identify cells in tissue and as they enter these alternative lineages. The secreted protein α-amylase, the transcription factor MIST1, and aquaporin-5 are typical markers for acinar cells, and K19 is the classical ductal marker in salivary tissue. We found that early ductal progenitors derived from hS/PCs do not express K19, and thus earlier markers were needed to distinguish these cells from acinar progenitors. Salivary ductal cells express distinct polarity complex proteins that we hypothesized could serve as lineage biomarkers to distinguish ductal cells from acinar cells in differentiating hS/PC populations. Based on our studies of primary salivary tissue, both parotid and submandibular glands, and differentiating hS/PCs, we conclude that the apical marker MUC1 along with the polarity markers INADL/PATJ and SCRIB reliably can identify ductal cells in salivary glands and in ductal progenitor populations of hS/PCs being used for salivary tissue engineering. Other markers of epithelial maturation, including E-cadherin, ZO-1, and partition complex component PAR3, are present in both ductal and acinar cells, where they can serve as general markers of differentiation but not lineage markers.

State of Rehabilitation Research in the Head and Neck Cancer Population: Functional Impact vs. Impairment-Focused Outcomes

PURPOSE OF REVIEW

Management of head and neck cancer (HNC) typically involves a morbid combination of surgery, radiation, and systemic therapy. As the number of HNC survivors grows, there is growing interest in rehabilitation strategies to manage HNC-related comorbidity. In this review, we summarize the current state of HNC rehabilitation research.

RECENT FINDINGS

We have organized our review using the World Health Organization's International Classification of Function (ICF) model of impairment, activity, and participation. Specifically, we describe the current research on rehabilitation strategies to prevent and treat impairments including dysphagia, xerostomia, dysgeusia, dysosmia, odynophagia, trismus, first bite syndrome, dysarthria, dysphonia, lymphedema, shoulder syndrome, cervicalgia, cervical dystonia and dropped head syndrome, deconditioning, and fatigue. We also discuss the broader impact of HNC-related impairment by exploring the state of rehabilitation literature on activity, participation, psychosocial distress, and suicidality in HNC survivors. We demonstrate that research in HNC rehabilitation continues to focus primarily on impairment-driven interventions. There remains a dearth of HNC rehabilitation studies directly examining the impact of rehabilitation interventions on outcomes related to activity and participation. More high-quality interventional studies and reviews are needed to guide prevention and treatment of functional loss in HNC survivors.

Therapeutic Advancements in Metal and Metal Oxide Nanoparticle-Based Radiosensitization for Head and Neck Cancer Therapy

Although radiation therapy (RT) is one of the mainstays of head and neck cancer (HNC) treatment, innovative approaches are needed to further improve treatment outcomes. A significant challenge has been to design delivery strategies that focus high doses of radiation on the tumor tissue while minimizing damage to surrounding structures. In the last decade, there has been increasing interest in harnessing high atomic number materials (Z-elements) as nanoparticle radiosensitizers that can also be specifically directed to the tumor bed. Metallic nanoparticles typically display chemical inertness in cellular and subcellular systems but serve as significant radioenhancers for synergistic tumor cell killing in the presence of ionizing radiation. In this review, we discuss the current research and therapeutic efficacy of metal nanoparticle (MNP)-based radiosensitizers, specifically in the treatment of HNC with an emphasis on gold- (AuNPs), gadolinium- (AGdIX), and silver- (Ag) based nanoparticles together with the metallic oxide-based hafnium (Hf), zinc (ZnO) and iron (SPION) nanoparticles. Both in vitro and in vivo systems for different ionizing radiations including photons and protons were reviewed. Finally, the current status of preclinical and clinical studies using MNP-enhanced radiation therapy is discussed.

Immune-Related Oral, Otologic, and Ocular Adverse Events

Emerging immunotherapeutic agents, including immune checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed cell death protein ligand 1 (PD-L1), have revolutionized cancer treatment. The first immune checkpoint inhibitor (ICI) ipilimumab, an anti-CTLA-4, was approved in 2011. Since then, the US Food and Drug Administration (FDA) has approved more than half a dozen immune checkpoint inhibitors to treat various malignancies. These agents are part of a broader class of chemotherapy agents termed immunotherapy, which selectively target different steps in the immune response cascade to upregulate the body's normal response to cancer. While the effects of traditional chemotherapy are well known, the toxicity profile of emerging immune therapies is not fully elucidated. They have been associated with atypical side effects labeled collectively as immune-related adverse events (irAEs).

OUP accepted manuscript

No effective therapy exists for the most common long-term side effect of radiation therapy for head and neck cancer (HNC)—xerostomia. The objective was to evaluate safety and provide proof of concept for efficacy of allogeneic adipose tissue-derived mesenchymal stem/stromal cells (AT-MSCs) injected into the major salivary glands of irradiated patients. This open-label, first-in-human, phase 1b, and single-center trial was conducted with repeated measurements days 0, 1, 5, and 30 and 4 months. Eligible patients with objective and subjective signs of radiation-induced salivary gland damage after treatment of oropharyngeal squamous cell carcinoma stages I-II (UICC 8) were enrolled. Twenty-five million cryopreserved AT-MSCs were injected into each submandibular and 50 million AT-MSCs into each parotid gland. Data were collected on adverse events, unstimulated and stimulated whole saliva (UWS and SWS) flow rates and saliva composition, patient-reported outcomes (EORTC QLQ-H&N35 and Xerostomia Questionnaire [XQ]), blood samples and salivary gland scintigraphy. Data were analyzed using repeated measures linear mixed models. Ten patients (7 men, 3 women, 59.5 years [range: 45-70]) were treated in 4 glands. No treatment-related serious adverse events occurred. During 4 months, UWS flow rate increased from 0.13 mL/minute at baseline to 0.18 mL/minute with a change of 0.06 (P = .0009) mL/minute. SWS flow rate increased from 0.66 mL/minute at baseline to 0.75 mL/minute with a change of 0.09 (P = .017) mL/minute. XQ summary score decreased by 22.6 units (P = .0004), EORTC QLQ-H&N35 dry mouth domains decreased by 26.7 (P = .0013), sticky saliva 23.3 (P = .0015), and swallowing 10.0 (P = .0016). Our trial suggests treatment of the major salivary glands with allogenic AT-MSCs is safe, warranting confirmation in larger trials.

Selected functional outcomes in advanced oral cancer: Comparison of surgery alone versus surgery with postoperative radiotherapy

BACKGROUND

Study objectives were to determine whether the addition of postoperative radiation (PORT) resulted in a decline in oral function relative to surgery alone and to describe the longitudinal course of oral function following treatment of advanced oral cancer.

METHODS

This was a 36-month retrospectively analyzed observational cohort study of patients with stage III-IV oral cancer. Prospectively collected, oral functional outcomes were acquired pretreatment and 3, 6, 12, 24, and 36 months post-treatment.

RESULTS

One hundred and eighteen patients were included. Forty-three patients treated with surgery alone were compared to 75 who received surgery with PORT. Mixed model analysis demonstrated the acute effect of PORT was associated with patient-rated xerostomia (p < 0.001) and the late or persistent effect was associated with decreased clinician-rated eating in public (p = 0.008), understandability of speech (p = 0.02), and normalcy of diet (p = 0.005) compared with surgery alone. There were no differences between surgery alone and PORT groups in clinician-rated feeding tube dependence or patient-rated speech handicap.

CONCLUSIONS

The use of PORT was associated with a demonstrable decline in oral function in four of six outcomes measures relative to surgery alone.

Upright epiglottis prevents aspiration in patients with nasopharyngeal carcinoma post-chemoradiation

NPC is the most widely found malignant tumor in the head and neck region in Indonesia. Chemoradiation therapy for NPC can induce swallowing disorders (dysphagia) that adversely affects a patients quality of life. This study aimed to assess the swallowing process by flexible endoscopic evaluation of swallowing in patients with nasopharyngeal carcinoma after chemoradiation. Thirty-nine patients with NPC who had chemoradiation therapy more than one month previously underwent flexible endoscopic evaluation of swallowing and were assessed for oral transport time, sensation, standing-secretion, pre-swallowing leakage, residue, penetration, aspiration, and silent aspiration. The most common structural abnormalities were an upright and swollen epiglottis (89.4%), poor oral hygiene, and velopharyngeal closure defects (56.4%). This examination also revealed a mild degree of standing secretion (38.5%) and aspiration (10.3%). No penetration was observed in 64.1% of the patients, and no silent aspiration was observed in any of the patients. A severe degree of residue (45.7%) was observed when administering oatmeal, while the residue was mild to moderate when administering gastric rice, crackers, and milk. The residue changed to a mild degree (32.3%-51.4%) in all food administrations after the watering maneuver. The highest penetration was noted after oatmeal administration (42.8%), and the highest aspiration was found after milk administration (8.6%). Standing secretion in almost all patients was caused by hyposensitivity of the hypopharynx. Persistent residue and hyposensitivity of the hypopharynx led to aspiration. The low percentage of aspiration and silent aspiration might have been caused by the upright and swollen epiglottis that prevented aspiration. Poor oral hygiene and a dry mouth led to prolonged oral transport. Therefore, most patients had hypopharyngeal abnormalities in the form of a swollen and upright epiglottis. Secretion and food residue were also detected. Drinking helps to expedite the swallowing process by facilitating oral phase transport and reducing residues.

A two-stage genome-wide association study of radiation-induced acute toxicity in head and neck cancer

BACKGROUND

Most head and neck cancer (HNC) patients receive radiotherapy (RT) and develop toxicities. This genome-wide association study (GWAS) was designed to identify single nucleotide polymorphisms (SNPs) associated with common acute radiation-induced toxicities (RITs) in an HNC cohort.

METHODS

A two-stage GWAS was performed in 1279 HNC patients treated with RT and prospectively scored for mucositis, xerostomia, sticky saliva, and dysphagia. The area under the curve (AUC) was used to estimate the average load of toxicity during RT. At the discovery study, multivariate linear regression was used in 957 patients, and the top-ranking SNPs were tested in 322 independent replication cohort. Next, the discovery and the replication studies were meta-analyzed.

RESULTS

A region on 5q21.3 containing 16 SNPs showed genome-wide (GW) significance association at P-value < 5.0 × 10-8 with patient-rated acute xerostomia in the discovery study. The top signal was rs35542 with an adjusted effect size of 0.17*A (95% CI 0.12 to 0.23; P-value <  = 3.78 × 10-9). The genome wide significant SNPs were located within three genes (EFNA5, FBXL17, and FER). In-silico functional analysis showed these genes may be involved in DNA damage response and co-expressed in minor salivary glands. We found 428 suggestive SNPs (P-value < 1.0 × 10-5) for other toxicities, taken to the replication study. Eleven of them showed a nominal association (P-value < 0.05).

CONCLUSIONS

This GWAS suggested novel SNPs for patient-rated acute xerostomia in HNC patients. If validated, these SNPs and their related functional pathways could lead to a predictive assay to identify sensitive patients to radiation, which may eventually allow a more individualized RT treatment.

Laminin-1 Peptides Conjugated to Fibrin Hydrogels Promote Salivary Gland Regeneration in Irradiated Mouse Submandibular Glands

Previous studies demonstrated that salivary gland morphogenesis and differentiation are enhanced by modification of fibrin hydrogels chemically conjugated to Laminin-1 peptides. Specifically, Laminin-1 peptides (A99: CGGALRGDN-amide and YIGSR: CGGADPGYIGSRGAA-amide) chemically conjugated to fibrin promoted formation of newly organized salivary epithelium both in vitro (e.g., using organoids) and in vivo (e.g., in a wounded mouse model). While these studies were successful, the model's usefulness for inducing regenerative patterns after radiation therapy remains unknown. Therefore, the goal of the current study was to determine whether transdermal injection with the Laminin-1 peptides A99 and YIGSR chemically conjugated to fibrin hydrogels promotes tissue regeneration in irradiated salivary glands. Results indicate that A99 and YIGSR chemically conjugated to fibrin hydrogels promote formation of functional salivary tissue when transdermally injected to irradiated salivary glands. In contrast, when left untreated, irradiated salivary glands display a loss in structure and functionality. Together, these studies indicate that fibrin hydrogel-based implantable scaffolds containing Laminin-1 peptides promote secretory function of irradiated salivary glands.

Fungal diseases: Oral dysbiosis in susceptible hosts

The oral cavity is colonized by a large number of microorganisms that are referred to collectively as the oral microbiota. These indigenous microorganisms have evolved in symbiotic relationships with the oral mucosal immune system and are involved in maintaining homeostasis in the oral cavity. Although Candida species are commonly found in the healthy oral cavity without causing infection, these fungi can become pathogenic. Recents advances indicate that the development of oral candidiasis is driven both by Candida albicans overgrowth in a dysbiotic microbiome and by disturbances in the host's immune system. Perturbation of the oral microbiota triggered by host-extrinsic (ie, medications), host-intrinsic (ie, host genetics), and microbiome-intrinsic (ie, microbial interactions) factors may increase the risk of oral candidiasis. In this review, we provide an overview of the oral mycobiome, with a particular focus on the interactions of Candida albicans with some of the most common oral bacteria and the oral mucosal immune system. Also, we present a summary of our current knowledge of the host-intrinsic and host-extrinsic factors that can predispose to oral candidiasis.

Oral Complications of Head and Neck Cancer Therapy

Current therapies for Head and Neck cancer treatment are extremely advanced. Though, they cause oral complications which have deleterious effects on basic life functions, affect oral and overall health, may lead to significant morbidity and treatment discontinuation and have an impact on survivorship and quality of life. As new therapies are introduced, a new spectrum of oral complications is rising, compromising the mucosal integrity and the salivary function, that may not be recognized, reported and treated properly. Oral complications, often permanent and extremely painful, may include mucositis, xerostomia, dysgeusia, infections, trismus and fibrosis, risk of dental disease and necrosis of the jaw, neurosensory disorders and when targeted therapies and immunotherapy are involved, aphthoid and lichenoid lesions can also be reported. Increased awareness is required for the prevention and management of these complications, which can be best provided by a multidisciplinary team.

Serum MicroRNAs as Xerostomia Biomarkers in Patients With Oropharyngeal Cancer Undergoing Radiation Therapy

PURPOSE

Severe xerostomia is noted in the majority of patients irradiated for oropharyngeal cancer. Extracellular microRNAs (miRNAs) may serve as effective tools allowing prediction of radiation-related toxicity. The aim of this study was to create an efficient prognostic miRNA-based test for severe, patient-rated xerostomia 3 months after primary treatment.

METHODS AND MATERIALS

This prospective study enrolled patients with oropharyngeal cancer treated between 2016 and 2018 in 3 centers in Poland. The primary endpoint was severe (grade ≥3) xerostomia as assessed by the European Organisation for Research and Treatment of Cancer H&N-35 questionnaires. Initially, a group of 10 patients with severe xerostomia was randomly selected and matched with a comparative group of 10 patients without severe xerostomia. Samples were collected before radiation therapy, after receiving 20 Gy, and within 24 hours after treatment completion. Quantitative real-time polymerase chain reaction arrays (QIAGEN, Hilden, Germany) were used to quantify expression levels of 752 miRNAs in the serum at all timepoints. The resulting logistic-regression based model was validated in additional 60 patients: 30 with grade >3 xerostomia and 30 without.

RESULTS

Of 152 eligible patients, we successfully recruited 111 patients. Severe xerostomia 3 months after treatment was reported by 63 patients (56.8%). Mean dose delivered to parotid glands was higher in both the exploratory and validation cohort. The model based on miR-185-5p and miR-425-5p expression levels measured before the start of radiation therapy had an area under the curve of 0.96 (95% confidence interval, 0.88-1.00). The model based on the same miRNAs remained robust when parameters were measured after 20 Gy (area under the curve 0.90; 95% confidence interval, 0.75-1.00). These results were confirmed in the validation group. In the validation group, preradiation therapy model application yielded 73.3% sensitivity and 80.0% specificity. In the samples taken after 20 Gy, the same 2 miRNAs yielded 67.7% sensitivity and 72.4% specificity. The model including pretreatment miR-185-5p and miR-425-5p levels together with mean parotid dose yielded 90.0% sensitivity and 80.0% specificity. In the validation cohort, this model yielded 80.6% sensitivity and 55.2% specificity. The model based on miRNA levels measured after 20 Gy and mean parotid dose had 80.0% sensitivity and 100% specificity in the exploratory group. In the validation cohort its performance fell to 71.0% sensitivity and 58.6% specificity.

CONCLUSIONS

Serum expression levels of miR-425-5p and miR-185-5p measured before the start of radiation therapy or during therapy (after 20 Gy) had significant prognostic value for the occurrence of severe xerostomia 3 months after treatment completion. The variability explained by miRNAs appears to be, at least partially, independent from that related to the dosimetric data.

Postoperative Radiation Therapy Refusal in Human Papillomavirus-Associated Oropharyngeal Squamous Cell Carcinoma

OBJECTIVES/HYPOTHESIS

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is a distinct clinical entity with good prognosis, unique demographics, and a trend toward treatment deintensification. Patients with this disease may opt out of recommended postoperative radiation therapy (PORT) for a variety of reasons. The aim of this paper was to examine factors that predict patient refusal of recommended PORT in HPV-associated OPSCC, and the association of refusal with overall survival.

STUDY DESIGN

Retrospective population-based cohort study of patients in the National Cancer Database.

METHODS

We conducted a retrospective cohort study of patients in the National Cancer Database diagnosed with OPSCC between January 2010 and December 2015. We primarily assessed overall survival and the odds of refusing PORT based on demographic, socioeconomic, and clinical factors. Analysis was conducted using multivariable logistic regression and multivariable Cox proportional hazards model.

RESULTS

A total of 4229 patients were included in the final analysis, with 156 (3.7%) patients opting out of recommended PORT. On multivariable analysis, patient refusal of PORT was independently associated with a variety of socioeconomic factors such as race, insurance status, comorbidity, treatment at a single facility, and margin status. Lastly, PORT refusal was associated with significantly lower overall survival compared to receipt of recommended PORT (hazard ratio 1.69, confidence interval 1.02-2.82).

CONCLUSIONS

Patient refusal of recommended PORT in HPV-associated OPSCC is rare and associated with variety of disease and socioeconomic factors. PORT refusal may decrease overall survival in this population. Our findings may help clinicians when counseling patients and identifying those who may be more likely to opt out of recommended adjuvant therapy.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Dosimetric Parameters Predicting Tooth Loss after Carbon Ion Radiotherapy for Head and Neck Tumors

Background: Tooth loss reduces quality of life; however, little is known about tooth loss caused by carbon ion radiotherapy (CIRT). Here, we aimed to elucidate the incidence of tooth loss post-CIRT for head and neck tumors and to identify risk-predictive dosimetric parameters. Methods: This study enrolled 14 patients (i.e., 171 teeth in total) with head and neck non-squamous cell carcinoma. All patients received CIRT comprised of 57.6 or 64.0 Gy (relative biological effectiveness, RBE) in 16 fractions. Dose–volume analysis of the teeth was performed using receiver operating characteristic (ROC) curve analysis with VX (i.e., the volume irradiated with X Gy (RBE)). Results: The median follow-up period was 69.1 months. The median time of tooth loss was 38.6 months. The 5 year cumulative incidence of tooth loss was 13.3%. The volume of irradiated teeth was significantly greater for the lost teeth than for the remaining teeth throughout the dose range. Using the cut-offs calculated from ROC curve analysis, V30–V60 showed high accuracy (i.e., >94%) for predicting tooth loss, with V50 being the most accurate (cut-off, 58.1%; accuracy, 0.95). Conclusions: This is the first report to examine the incidence of tooth loss post-CIRT and to identify risk-predictive dosimetric parameters.

Radiation-induced swallowing dysfunction in patients with head and neck cancer: A literature review

Swallowing dysfunction is a prevailing state following radiotherapy in patients with head and neck cancer. Following the advancement of cancer treatment in recent years, the survival rate of head and neck cancer has gradually increased. Simultaneously, patients with head and neck cancer suffer due to the long-duration and more prominent swallowing dysfunction states. Based on an extensive literature review, we aimed to explore the mechanisms, risk factors, and clinical evaluations of swallowing dysfunction and their related symptoms following radiotherapy. These include functional changes of the muscles, trismus, xerostomia, neuropathy, and lymphedema. When swallowing dysfunction occurs, patients usually seek medical help and are referred for rehabilitation therapy, such as muscle strengthening and tongue resistance exercise. Furthermore, clinicians should discuss with patients how and when to place the feeding tube. Only through detailed evaluation and management can swallowing dysfunction resolve and improve the quality of life of patients with head and neck cancer following radiotherapy.

The evaluation of the reliability and validity properties of the Greek version of the xerostomia questionnaire (ΧQ)

PURPOSE

Xerostomia is one of the multidimensional effects of cancer therapy that can impact on patients' quality of life. This study aims to evaluate the reliability and validity properties of the xerostomia questionnaire.

METHODS

The data were retrieved from a randomized, interventional and longitudinal follow-up study of 72 head and neck cancer patients on active oral radiotherapy. Data were retrieved by the Xerostomia Questionnaire, the EORTC-QLQ C30 and EORT QLQ HN35. Data analyzes included intrinsic credibility of affinity Cronbach alpha factor, which is related to validity and cross-sectional validity.

RESULTS

The Cronbach's alpha index of the Greek version of the questionnaire was high. Explicitly, the total scale of the questionnaire had an α = 0.97, and the individual dimensions - Degree of dryness and the quality of life had an alpha of 0.97 and 0.98 respectively. The xerostomia dimension of the questionnaire has a high positive correlation with QLQ C30 overall (r = 0.61, p < 0.001), and with the HN35 xerostomia dimension (r = 0.63, p < 0.001) which demonstrate its' concurrent validity. The dimensions of the xerostomia questionnaire were highly correlated with the EORTC-QLQ C30 dimensions which supports its' predictive validity. The level of xerostomia and the quality of life varied according to the level of pain of the patients (p < 0.001) that support the cross-sectional validity of the questionnaire.

CONCLUSION

The Greek version of the xerostomia questionnaire is a reliable and valid tool for use in head and neck cancer patients on active oral radiotherapy.

Individualized 3D-Printed Tissue Retraction Devices for Head and Neck Radiotherapy

Background

Radiotherapy for head and neck cancer may cause various oral sequelae, such as radiation-induced mucositis. To protect healthy tissue from irradiation, intraoral devices can be used. Current tissue retraction devices (TRDs) have to be either individually manufactured at considerable cost and time expenditure or they are limited in their variability. In this context, a 3D-printed, tooth-borne TRD might further facilitate clinical use.

Methods

A novel approach for the manufacturing of TRDs is described and its clinical application is analysed retrospectively. The devices were virtually designed for fabrication by 3D-printing technology, enabling—in only a single printing design—caudal or bi-lateral tongue displacement, as well as stabilization of a tongue-out position. For a total of 10 patients undergoing radiotherapy of head and neck tumors, the devices were individually adapted after pre-fabrication. Technical and clinical feasibility was assessed along with patient adherence. Tissue spacing was calculated by volumetric analysis of tongue retraction. In one exemplary case, radiotherapy treatment plans before and after tissue displacement were generated and compared. The reproducibility of maxillomandibular relation at device re-positioning was quantified by repeated intraoral optical scanning in a voluntary participant.

Results

3D-printing was useful for the simplification of TRD manufacture, resulting in a total patient treatment time of less than 30 min. The devices were tolerated well by all tested patients over the entire radiation treatment period. No technical complications occurred with the devices. The TRDs caused an effective spacing of the healthy adjacent tissue, e.g., the tongue. Position changes of maxillomandibular relation were limited to a mean value of 98.1 µm ± 29.4 µm root mean square deviation between initial reference and follow-up positions.

Conclusions

The presented method allows a resource-efficient fabrication of individualized, tooth-bourne TRDs. A high reproducibility of maxillomandibular relation was found and the first clinical experiences underline the high potential of such devices for radiotherapy in the head and neck area.

Dysbiosis From a Microbial and Host Perspective Relative to Oral Health and Disease

The significance of microbiology and immunology with regard to caries and periodontal disease gained substantial clinical or research consideration in the mid 1960's. This enhanced emphasis related to several simple but elegant experiments illustrating the relevance of bacteria to oral infections. Since that point, the understanding of oral diseases has become increasingly sophisticated and many of the original hypotheses related to disease causality have either been abandoned or amplified. The COVID pandemic has reminded us of the importance of history relative to infectious diseases and in the words of Churchill "those who fail to learn from history are condemned to repeat it." This review is designed to present an overview of broad general directions of research over the last 60 years in oral microbiology and immunology, reviewing significant contributions, indicating emerging foci of interest, and proposing future directions based on technical advances and new understandings. Our goal is to review this rich history (standard microbiology and immunology) and point to potential directions in the future (omics) that can lead to a better understanding of disease. Over the years, research scientists have moved from a position of downplaying the role of bacteria in oral disease to one implicating bacteria as true pathogens that cause disease. More recently it has been proposed that bacteria form the ecological first line of defense against "foreign" invaders and also serve to train the immune system as an acquired host defensive stimulus. While early immunological research was focused on immunological exposure as a modulator of disease, the "hygiene hypothesis," and now the "old friends hypothesis" suggest that the immune response could be trained by bacteria for long-term health. Advanced "omics" technologies are currently being used to address changes that occur in the host and the microbiome in oral disease. The "omics" methodologies have shaped the detection of quantifiable biomarkers to define human physiology and pathologies. In summary, this review will emphasize the role that commensals and pathobionts play in their interaction with the immune status of the host, with a prediction that current "omic" technologies will allow researchers to better understand disease in the future.

Integration of metabolomics and transcriptomics reveals convergent pathways driving radiation-induced salivary gland dysfunction

Radiation therapy for head and neck cancer causes damage to the surrounding salivary glands, resulting in salivary gland hypofunction and xerostomia. Current treatments do not provide lasting restoration of salivary gland function following radiation; therefore, a new mechanistic understanding of the radiation-induced damage response is necessary for identifying therapeutic targets. The purpose of the present study was to investigate the metabolic phenotype of radiation-induced damage in parotid salivary glands by integrating transcriptomic and metabolomic data. Integrated data were then analyzed to identify significant gene-metabolite interactions. Mice received a single 5 Gy dose of targeted head and neck radiation. Parotid tissue samples were collected 5 days following treatment for RNA sequencing and metabolomics analysis. Altered metabolites and transcripts significantly converged on a specific region in the metabolic reaction network. Both integrative pathway enrichment using rank-based statistics and network analysis highlighted significantly coordinated changes in glutathione metabolism, energy metabolism (TCA cycle and thermogenesis), peroxisomal lipid metabolism, and bile acid production with radiation. Integrated changes observed in energy metabolism suggest that radiation induces a mitochondrial dysfunction phenotype. These findings validated previous pathways involved in the radiation-damage response, such as altered energy metabolism, and identified robust signatures in salivary glands, such as reduced glutathione metabolism, that may be driving salivary gland dysfunction.

Trans-cutaneous electrical nerve stimulation to treat dry mouth (xerostomia) following radiotherapy for head and neck cancer. A systematic review

BACKGROUND

A dry mouth or xerostomia is one of the most common long-term complications following radiotherapy for head and neck cancer and has a negative impact on quality of life in cancer survivors. Transcutaneous electrical nerve stimulation (TENS) is a novel approach to improving saliva flow in these patients.

OBJECTIVE

To perform a systematic review of studies evaluating TENS in the treatment of radiotherapy induced xerostomia in head and neck cancer patients.

DATA COLLECTION AND ANALYSIS

A comprehensive electronic search was performed in PubMed/MEDLINE, the Cochrane Library, and Google Scholar databases for appropriate published studies. The last search was conducted in January 2020. Two review authors assessed all studies identified by the search strategy and carried out data extraction.

RESULTS

Five studies were included in the systematic review which analysed a total of 280 patients with head and neck cancer. Methodological quality and outcomes were evaluated in every study included. The outcome measure was either subjectively assessed or objectively measured. Three studies used conventional TENS therapy to stimulate parotid glands which produced a significant increase in saliva production following therapy. Two studies used acupunctured TENS type to electrically stimulate acupuncture points scattered in the body and they reported improvement in saliva production at the same level as medical treatment. No reported adverse effect of TENS was identified.

CONCLUSIONS

This systematic review confirms the safety and feasibility of TENS in the treatment of xerostomia. It is established that commencing daily TENS therapy simultaneously with radiotherapy has the most efficacy. Given the nonspecific parameters used in the included studies, further evidence is needed in order to establish optimal settings and parameters of TENS for treatment of xerostomia.