Oral mucositis and microbial colonization in oral cancer patients undergoing radiotherapy and chemotherapy: A prospective analysis in a tertiary care dental hospital

Nano-Drug Delivery Systems in Oral Cancer Therapy: Recent Developments and Prospective

Oral cancer (OC), characterized by malignant tumors in the mouth, is one of the most prevalent malignancies worldwide. Chemotherapy is a commonly used treatment for OC; however, it often leads to severe side effects on human bodies. In recent years, nanotechnology has emerged as a promising solution for managing OC using nanomaterials and nanoparticles (NPs). Nano-drug delivery systems (nano-DDSs) that employ various NPs as nanocarriers have been extensively developed to enhance current OC therapies by achieving controlled drug release and targeted drug delivery. Through searching and analyzing relevant research literature, it was found that certain nano-DDSs can improve the therapeutic effect of drugs by enhancing drug accumulation in tumor tissues. Furthermore, they can achieve targeted delivery and controlled release of drugs through adjustments in particle size, surface functionalization, and drug encapsulation technology of nano-DDSs. The application of nano-DDSs provides a new tool and strategy for OC therapy, offering personalized treatment options for OC patients by enhancing drug delivery, reducing toxic side effects, and improving therapeutic outcomes. However, the use of nano-DDSs in OC therapy still faces challenges such as toxicity, precise targeting, biodegradability, and satisfying drug-release kinetics. Overall, this review evaluates the potential and limitations of different nano-DDSs in OC therapy, focusing on their components, mechanisms of action, and laboratory therapeutic effects, aiming to provide insights into understanding, designing, and developing more effective and safer nano-DDSs. Future studies should focus on addressing these issues to further advance the application and development of nano-DDSs in OC therapy.

Targeting anticancer immunity in oral cancer: Drugs, products, and nanoparticles

Oral cavity carcinomas are the most frequent malignancies among head and neck malignancies. Oral tumors include not only oral cancer cells with different potency and stemness but also consist of diverse cells, containing anticancer immune cells, stromal and also immunosuppressive cells that influence the immune system reactions. The infiltrated T and natural killer (NK) cells are the substantial tumor-suppressive immune compartments in the tumor. The infiltration of these cells has substantial impacts on the response of tumors to immunotherapy, chemotherapy, and radiotherapy. Nevertheless, cancer cells, stromal cells, and some other compartments like regulatory T cells (Tregs), macrophages, and myeloid-derived suppressor cells (MDSCs) can repress the immune responses against malignant cells. Boosting anticancer immunity by inducing the immune system or repressing the tumor-promoting cells is one of the intriguing approaches for the eradication of malignant cells such as oral cancers. This review aims to concentrate on the secretions and interactions in the oral tumor immune microenvironment. We review targeting tumor stroma, immune system and immunosuppressive interactions in oral tumors. This review will also focus on therapeutic targets and therapeutic agents such as nanoparticles and products with anti-tumor potency that can boost anticancer immunity in oral tumors. We also explain possible future perspectives including delivery of various cells, natural products and drugs by nanoparticles for boosting anticancer immunity in oral tumors.

Radioprotective potential of whey protein against gamma irradiation-induced lingual damage

Introduction: Ionizing radiation (IR) is effectively used in the treatment of oral malignancies; however, it might also significantly harm the surrounding tissues. Whey protein isolate (WP) is a protein derived from milk that exhibits a wide range of bioactivities. Therefore, the present research aimed to delineate the mitigating impact of WP against gamma irradiation-induced lingual damage. Methods: Rats were randomized into 5 groups: Control (saline, orally, 14 days), WP (WP; 0.5 g/kg b. w., orally, 14 days), IR (saline, orally, 14 days, exposed to 6 and 3 Gy on days 4 and 6, respectively), WP+IR (WP was given orally for 14 days before and after IR exposure; exposed to 6 and 3 Gy on days 4 and 6, respectively), and IR+WP (WP, orally, started 24 h after 1st IR exposure till the end of the experiment) groups. Samples were collected at two-time intervals (on the 7th and 14th days). Results and Discussion: Oxidative stress was stimulated upon IR exposure in tongue, indicated by boosted malondialdehyde (MDA) level, along with a decrease in the total antioxidant capacity (TAC) level, superoxide dismutase (SOD), and catalase (CAT) activities. Additionally, IR exposure depicted an increase of serum IgE, inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin (IL)-6, along with overexpression mRNA levels of nuclear factor kappa-B transcription factor/p65 (NF-κB/p65), and down-regulation of nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase (HO-1) mRNA levels in tongue tissue. Moreover, IR triggered alterations in lingual histological architecture. The antioxidant and anti-inflammatory properties of WP mitigated oxidative damage, inflammation, and desquamation that were brought on following IR exposure. The protective administration of WP markedly decreases IR-induced lingual harm compared to the mitigation protocol. Our findings recommend WP supplements to the diets of cancer patients undergoing IR that might aid radioprotective effects.

Metronomic Chemotherapy in Oral Cancer: A Review

Treatment of locally advanced oral cancer requires multidisciplinary care, including surgery, radiotherapy, and chemotherapy, which varies based on the stage of the disease, site of involvement, and surgical access. Oral cancer usually presents with an increased recurrence rate and potential for distant metastatic spread. It confers a poor prognosis with a 50% mortality rate after five years. Oral metronomic chemotherapy aims to achieve higher patient compliance due to its ease of administration, lower dosage, and lesser side effects than conventional IV regimens of platinum-based drugs. In this review, we have summarized the relevant literature to benefit the readers regarding the potential application of metronomic therapy in the management of oral cancer.

Attempts to Understand Oral Mucositis in Head and Neck Cancer Patients through Omics Studies: A Narrative Review

Oral mucositis (OM) is a common and clinically impactful side effect of cytotoxic cancer treatment, particularly in patients with head and neck squamous cell carcinoma (HNSCC) who undergo radiotherapy with or without concomitant chemotherapy. The etiology and pathogenic mechanisms of OM are complex, multifaceted and elicit both direct and indirect damage to the mucosa. In this narrative review, we describe studies that use various omics methodologies (genomics, transcriptomics, microbiomics and metabolomics) in attempts to elucidate the biological pathways associated with the development or severity of OM. Integrating different omics into multi-omics approaches carries the potential to discover links among host factors (genomics), host responses (transcriptomics, metabolomics), and the local environment (microbiomics).

Tumor microenvironment remodeling in oral cancer: Application of plant derived-natural products and nanomaterials

Oral cancers consist of squamous cell carcinoma (SCC) and other malignancies in the mouth with varying degrees of invasion and differentiation. For many years, different modalities such as surgery, radiation therapy, and classical chemotherapy drugs have been used to control the growth of oral tumors. Nowadays, studies have confirmed the remarkable effects of the tumor microenvironment (TME) on the development, invasion, and therapeutic resistance of tumors like oral cancers. Therefore, several studies have been conducted to modulate the TME in various types of tumors in favor of cancer suppression. Natural products are intriguing agents for targeting cancers and TME. Flavonoids, non-flavonoid herbal-derived molecules, and other natural products have shown promising effects on cancers and TME. These agents, such as curcumin, resveratrol, melatonin, quercetin and naringinin have demonstrated potency in suppressing oral cancers. In this paper, we will review and discuss about the potential efficacy of natural adjuvants on oral cancer cells. Furthermore, we will review the possible therapeutic effects of these agents on the TME and oral cancer cells. Moreover, the potential of nanoparticles-loaded natural products for targeting oral cancers and TME will be reviewed. The potentials, gaps, and future perspectives for targeting TME by nanoparticles-loaded natural products will also be discussed.

Assessment of Salivary ABO Blood Group Antigens and Secretor Status in Sriganganagar, Rajasthan: A Correlational Analysis of 300 Samples

Aim To estimate the ABO blood groups from saliva samples and to correlate with the secretor status. Materials and methods A sample size of 300 individuals was selected from the outpatient department of Surendera Dental College & Research Institute, Sriganganagar, India, and from dental camps organized by the college in the near vicinity. Informed consent was obtained from selected individuals to collect their blood and saliva samples. Salivary samples were evaluated for ABO blood groups by the absorption-inhibition method. The indicator erythrocytes were prepared after blood group confirmation from serum. It was used to identify the blood group antigens in saliva to confirm the secretor status. The results were tabulated and the Pearson's chi-squared test was performed for statistical analysis using SPSS 15.0 (SPSS Inc., Chicago, IL). Results The present study showed that 282 subjects (94%) were Rhesus positive and 18 subjects (6%) were Rhesus negative. Two-hundred-and-fifty subjects (83.3%) were secretors of antigens in saliva. Non-secretors were 50 subjects (16.7%). We identified that 250/300 were secretors and the majority were in AB & A group. Conclusion Blood groups could not be detected from the saliva of subjects who were non-secretors. In contrast, blood types could be accurately identified from the saliva of those subjects who were secretors of antigen.

Antimicrobial photodynamic therapy for the treatment of oral mucositis - a comparative study

OBJECTIVES

The aim was to evaluate the effectiveness of the photobiomodulation associated to antimicrobial photodynamic therapy in the treatment of oral mucositis.

BACKGROUND

Oral Mucositis is a frequent complication of oral cavity and oropharynx cancer. Considering the OM aggravation by microorganisms contamination, disinfection provide by antimicrobial photodynamic therapy could be an effective approach.

MATERIAL AND METHODS

This comparative study included fourteen patients undergoing radiochemotherapy for oral cavity and oropharynx cancer treatment, who developed oral mucositis.

CONTROL GROUP

photobiomodulation. Intervention group: photobiomodulation and antimicrobial photodynamic therapy. The lesion size, duration, pain, and identification of microorganisms were evaluated.

RESULTS

The mean reduction in oral mucositis size in the intervention group was 0.70 cm² (±0.35) and 0.30 cm² (±1.10) for the control group. The mean duration of oral mucositis was 18.37 days (±12.12) for the intervention group and 23 days (±14.78) for the control group. The intervention group had a mean reduction of 3.40 points on the pain scale (±2.44), while the control group had 0.17 (±2.28). In the intervention group, the predominant isolated microbiota was featured as mixed culture (n=4/ 50%), followed of Gram Positive (n=3/ 37.50%), and Gram Negative (n=1/ 12.55%). In the control group, mixed culture was also more frequent (n=4 / 66%), followed by Gram Positive (n=2 /34%). Gram Negative was not predominantly isolated in the control group.

CONCLUSION

No statistical significance was found between PBM-T alone and PBM-T + PDT. However, the better outcomes reached by PBM-T + PDT group would suggest there could be a role for combined treatment in the management of OM lesions.

Oral microbiota dysbiosis accelerates the development and onset of mucositis and oral ulcers

With the rapid development of metagenomic high-throughput sequencing technology, more and more oral mucosal diseases have been proven to be associated with oral microbiota shifts or dysbiosis. The commensal oral microbiota can greatly influence the colonization and resistance of pathogenic microorganisms and induce primary immunity. Once dysbiosis occurs, it can lead to damage to oral mucosal epithelial defense, thus accelerating the pathological process. As common oral mucosal diseases, oral mucositis and ulcers seriously affect patients' prognosis and quality of life. However, from the microbiota perspective, the etiologies, specific alterations of oral flora, pathogenic changes, and therapy for microbiota are still lacking in a comprehensive overview. This review makes a retrospective summary of the above problems, dialectically based on oral microecology, to provide a new perspective on oral mucosal lesions management and aims at improving patients' quality of life.

Chitosan as a potential biomaterial for the management of oral mucositis, a common complication of cancer treatment

Oral mucositis is a serious issue in patients receiving oncological therapies. Mucosal protectants considered to be one of the preferred choices used in the management of mucositis. However, the protective efficacy of currently available mucosal protectants has been significantly compromised due to poor retention, lack of lubrication, poor biodegradability, and inability to manage secondary complications. Chitosan is a promising material for mucosal applications due to its beneficial biomedical properties. Chitosan is also anti-inflammatory, anti-microbial, and capable of scavenging free radicals, makes it a good candidate for the treatment of oral mucositis. Additionally, chitosan's amino polysaccharide skeleton permits a number of chemical alterations with better bioactive performance. This article provides a summary of key biological properties of chitosan and its derivatives that are useful for treating oral mucositis. Current literature evidence shows that Chitosan has superior mucosal protective properties when utilised alone or as delivery systems for co-encapsulated drugs.

Assessment of Oral Lesions With Tobacco Usage: A Cross-Sectional Clinicopathological Study in Sri Ganganagar, Rajasthan, India

Background Tobacco usage in the form of smoking or chewing has increased the risk of oral potentially malignant disorders (OPMDs) and oral cancer. These deleterious habits are also related to changes in dentition and the oral mucosa. Aim The aim of our study was to evaluate the oral changes associated with tobacco usage among residents of Sri Ganganagar. Materials and methods This study was conducted among the residents of Sri Ganganagar, Rajasthan, India, using stratified cluster random sampling, prestructured questionnaires, and detailed oral examination. A total of 100 patients with a previous history of tobacco usage were enrolled in this study after obtaining informed consent. Age- and gender-matched controls were also evaluated to correlate the findings. Clinical details were documented, including the Oral Hygiene Index-Simplified (OHI-S), Decayed-Missing-Filled Teeth (DMFT) index, Community Periodontal Index (CPI), loss of attachment, dental findings, and oral mucosal changes. Suspicious lesions were stained with toluidine blue, and a biopsy was performed for histopathological evaluation. The tabulated results were statistically analyzed using the Statistical Package for the Social Sciences (SPSS) version 21.0 (IBM SPSS Statistics, Armonk, NY, USA) for significance. Results Attrition, abrasion, and erosion of teeth were more frequent in tobacco users than in controls. Smoker's palate, tobacco pouch keratosis, and leukoplakia were commonly noted mucosal lesions. The mean values of the parameters of the DMFT score (3.560), CPI score (2.190), and loss of attachment score (0.542) were higher among tobacco users, and it was statistically significant (P value < 0.05). Out of 100 patients, 17 had suspicious lesions. It included seven cases of oral submucous fibrosis (OSMF), two cases of tobacco pouch keratosis, and eight cases of leukoplakia. Toluidine blue staining and biopsy were performed. Histopathological examination of suspicious lesions revealed hyperkeratosis, various grades of epithelial dysplasia, and differing inflammatory responses. Out of 17 biopsied cases, there were two cases of hyperkeratosis with severe epithelial dysplasia, four cases of hyperkeratosis with moderate epithelial dysplasia, two cases of hyperkeratosis with mild dysplasia, two cases of superficially invasive squamous cell carcinoma, five cases of advanced OSMF, and two cases of moderately advanced OSMF. Conclusion Tobacco usage produces visible changes in dentition and latent alterations in the oral mucosa. Suspicious lesions should always be referred for histopathological examination to identify oral potentially malignant disorders and oral cancer so that prompt treatment could be initiated. Patient education is mandatory to avoid the usage of tobacco in any form.

Prophylactic management of radiation-induced mucositis using herbal mouthwash in patients with head and neck cancer: an assessor-blinded randomized controlled trial

OBJECTIVES

Radiation-induced mucositis (RIOM) is one of the most common side effects from head and neck radiotherapy. Several reagents have been introduced to manage the symptom; however, there is still a limited number of effective reagents. Herbal mouthwashes with payayor (Clinacanthus nutans Lindau) and fingerroot (Boesenbergia rotunda) were tested their efficacies in preventing and reducing severity of RIOM in comparison with normal saline with sodium bicarbonate.

METHODS

One hundred twenty patients with head and neck cancer undergoing radiotherapy participated in the study and were randomly assigned into three treatment groups using block randomization method. The participants were assigned one of the three mouthwashes for use throughout their radiotherapy course and were assessed for their mucositis scores from week one to six into their radiotherapy course as well as at one-month follow-up. Body mass index was also measured for comparison of nutritional status.

RESULTS

The two mouthwashes were similarly effective in prophylaxis of RIOM in term of severity. The averaged mucositis scores were less than two for all groups. For the onset of RIOM, both herbal mouthwashes could slightly delay the symptom but not statistically significant. Patients' body mass index across the three treatment groups was also comparable. The patients were largely satisfied with all the mouthwashes with no clear preference on any of them.

CONCLUSIONS

Prophylactic treatment of RIOM using herbal mouthwashes could substitute the current standard of normal saline with bicarbonate. A different formulation of the two herbs could potentially improve the prophylactic outcome.

TRIAL REGISTRATION NO

NCT03359187.

Impact of different fixed dental prostheses on radiation dose in helical tomotherapy as measured with metal oxide semiconductor field-effect transistor dosimetry

OBJECTIVE

This ex vivo study evaluated the effects of different fixed dental prostheses and protective materials on scattered radiation during radiation therapy (RT).

STUDY DESIGN

Natural teeth (group NT) and 4 types of prostheses (group BL: bilayer lithium disilicate glass-ceramic; group MZ: monolithic zirconia ceramic; group BZ: bilayer zirconia-based all ceramic; and group BM: bilayer metal-ceramic restorations) were examined in maxillary and mandibular arch phantoms. All groups were divided into 3 subgroups: (1) without protective material over the prostheses; (2) protected with a soft acrylic night guard; and (3) protected with polyvinylsiloxane putty. All groups were irradiated with helical RT at 2 Gy and 6 MV photon energy. Doses were measured internally and externally 3 times on each phantom. Results were significant at P < .05.

RESULTS

No statistically significant differences in doses were found between groups NT and BL in either phantom, but these groups were different from the others. The differences between groups BZ and MZ were insignificant. Doses in group BM were significantly larger than all other groups. No significant differences existed between doses with and without protective material.

CONCLUSIONS

Doses increased significantly due to scattered radiation from the prostheses with increasing material density. Protective materials had no significant effect on dose.

Evaluation of Bacteria and Fungi DNA Abundance in Human Tissues

Whereas targeted and shotgun sequencing approaches are both powerful in allowing the study of tissue-associated microbiota, the human: microorganism abundance ratios in tissues of interest will ultimately determine the most suitable sequencing approach. In addition, it is possible that the knowledge of the relative abundance of bacteria and fungi during a treatment course or in pathological conditions can be relevant in many medical conditions. Here, we present a qPCR-targeted approach to determine the absolute and relative amounts of bacteria and fungi and demonstrate their relative DNA abundance in nine different human tissue types for a total of 87 samples. In these tissues, fungi genomes are more abundant in stool and skin samples but have much lower levels in other tissues. Bacteria genomes prevail in stool, skin, oral swabs, saliva, and gastric fluids. These findings were confirmed by shotgun sequencing for stool and gastric fluids. This approach may contribute to a more comprehensive view of the human microbiota in targeted studies for assessing the abundance levels of microorganisms during disease treatment/progression and to indicate the most informative methods for studying microbial composition (shotgun versus targeted sequencing) for various samples types.

Interaction between properties of commercial Australian honey and saliva: in vitro exploratory study of a potential mechanism in the treatment of oral mucositis

OBJECTIVES

Oral mucositis is a debilitating oncology treatment side effect, with honey identified as a viable management option due to established wound-healing abilities. However, effects of saliva on properties attributed to honey's wound-healing abilities is unknown. Therefore, this study aimed to identify interactions between saliva, and antioxidant characteristics and pH of honey.

METHODS

Saliva was collected from 15 healthy participants (Females n=9; mean age=34.1 ± 11.2 years). Centrifuged salivary supernatant, whole saliva, and water were independently used to dilute commercial Australian honeys (n=42). Antioxidant characteristics (DPPH and FRAP) and pH of diluted honeys were analysed, and differences between dilution conditions were determined.

RESULTS

Honey and saliva dilutions increased antioxidant characteristics compared to water, and addition of honey to saliva reduced pH compared with saliva alone. There were significant differences between dilutions for FRAP and pH, and water and salivary conditions for DPPH (p<0.001). No difference was observed between salivary conditions for DPPH (p=0.931), suggesting smaller cells remaining in the supernatant possess antioxidant abilities. However, differences observed for FRAP suggest precipitable molecules, including epithelial and food debris, could provide additional antioxidant power.

CONCLUSIONS

The addition of saliva to honey may support properties attributed to honey's wound-healing abilities and should be considered in the context of oral mucositis management.

An Integrative Review of the Role of the Oral and Gut Microbiome in Oral Health Symptomatology During Cancer Therapy

PROBLEM IDENTIFICATION

Both chemotherapy and radiation therapy cause considerable symptom burden on patients' oral health, influencing nutritional status and quality of life. The role of the oral and gut microbiome in oral health alterations during cancer therapy is an emerging area of science in symptom management.

LITERATURE SEARCH

PubMed®, CINAHL®, and Scopus® were searched for articles published from January 2000 through July 2020.

DATA EVALUATION

Articles published in English that were focused on chemotherapy and/or radiation therapy were included in the review.

SYNTHESIS

Of the 22 identified studies, 12 described oral health symptoms during chemotherapy and radiation therapy for head and neck cancer. Ten studies assessed symptoms during treatment for a variety of solid tumors and blood cancers, with four of these describing microbial interventions for the management of oral mucositis. Interventions varied, but the results supported the benefits of probiotics and synbiotics in reducing mucositis severity. Overall, less diverse oral and gut microbiome environments were associated with increased severity of oral health symptomatology.

IMPLICATIONS FOR PRACTICE

Additional research is needed to determine how the oral and gut microbiome and microbial interventions may be used to improve oral health management during cancer treatment.

Preliminary insights into the impact of primary radiochemotherapy on the salivary microbiome in head and neck squamous cell carcinoma

Squamous cell carcinoma is the most common type of throat cancer. Treatment options comprise surgery, radiotherapy, and/or chemo(immuno)therapy. The salivary microbiome is shaped by the disease, and likely by the treatment, resulting in side effects caused by chemoradiation that severely impair patients’ well-being. High-throughput amplicon sequencing of the 16S rRNA gene provides an opportunity to investigate changes in the salivary microbiome in health and disease. In this preliminary study, we investigated alterations in the bacterial, fungal, and archaeal components of the salivary microbiome between healthy subjects and patients with head and neck squamous cell carcinoma before and close to the end point of chemoradiation (“after”). We enrolled 31 patients and 11 healthy controls, with 11 patients providing samples both before and after chemoradiation. Analysis revealed an effect on the bacterial and fungal microbiome, with a partial antagonistic reaction but no effects on the archaeal microbial community. Specifically, we observed an individual increase in Candida signatures following chemoradiation, whereas the overall diversity of the microbial and fungal signatures decreased significantly after therapy. Thus, our study indicates that the patient microbiome reacts individually to chemoradiation but has potential for future optimization of disease diagnostics and personalized treatments.

The Effectiveness Chewing gum versus Cryotherapy on Salivary Volume among Patient with Head and Neck Cancer undergoing Radiotherapy

Introduction: Hyposalivation is a common problem experienced by head and neck (H&N) cancer patients undergoing radiotherapy. Hyposalivation can cause negative effects on the physical aspects of making oral mucositis, pain during eating and talking as well as psychological effects that cause feeling of discomfort sadness and, ultimately, depression. Many nonpharmacological interventions can be done for hyposalivation that occur in patients, among which are chewing gum and cryotherapy because they are easy to do, easy to access, inexpensive and have minimal side effects. However, the effectiveness of these interventions is not yet clear. Hence, this study is aimed to determine the effectiveness of chewing gum versus cryotherapy to increase salivary volume in H&N cancer patients undergoing radiotherapy.Methods: A quasi-experimental time series group design to determine the most effective time to influence the increase in salivary volume. This research was conducted on 36 respondents H&N cancer undergoing radiotherapy with four times measurement are pretest-posttest on the 3rd, 5th, and 7th day of intervention between February and March 2020. Subjects were chosen using consecutive sampling. Chewing gum group will chew gum six (6) pieces/day and cryotherapy group will suck on ice cubes five (5) minutes before and after radiotherapy. The spitting method was used to collect saliva and the data were analyzed using General Linear Model-Repeated Measure (GLMRM).Results: Chewing gum is more effective to increase salivary volume than cryotherapy. The GLMRM within subjects at four (4) times measurement showed a significant difference between chewing gum and cryotherapy group with p value <0.05 on the 7th day. Subjects in the chewing gum group had better salivary volume increment than cryotherapy group.Conclusion: This study showed that chewing gum is more effective to increase salivary volume on patient H&N cancer undergoing radiotherapy because chewing gum has higher salivary volume increment than cryotherapy groups

Oral Mucositis: An Update on Innate Immunity and New Interventional Targets

Oral mucositis (OM), a common debilitating toxicity associated with chemo- and radiation therapies, is a significant unmet clinical need for head and neck cancer patients. The biological complexities of chemoradiotherapy-induced OM involve interactions among disrupted tissue structures, inflammatory infiltrations, and oral microbiome, whereby several master inflammatory pathways constitute the complicated regulatory networks. Oral mucosal damages triggered by chemoradiotherapy-induced cell apoptosis were further exacerbated by the amplified inflammatory cascades dominantly governed by the innate immune responses. The coexistence of microbiome and innate immune components in oral mucosal barriers indicates that a signaling hub coordinates the interaction between environmental cues and host cells during tissue and immune homeostasis. Dysbiotic shifts in oral microbiota caused by cytotoxic cancer therapies may also contribute to the progression and severity of chemoradiotherapy-induced OM. In this review, we have updated the mechanisms involving innate immunity-governed inflammatory cascades in the pathobiology of chemoradiotherapy-induced OM and the development of new interventional targets for the management of this severe morbidity in head and neck cancer patients.