Occurrence of field cancerization in clinically normal oral mucosa: A systematic review and meta-analysis

Validation of salivary proteomic biomarkers for early detection of oral cancer in the Egyptian population

PURPOSE

The present study evaluated the sensitivity and specificity of important proteomic salivary biomarkers; IL-6, IL-8, and sCD44 in the early detection of oral cancer, and any possible associations with risk factors of oral cancer in an Egyptian population.

METHODS

The present investigation was conducted on 100 individuals; 25 healthy controls, 25 patients having oral potentially malignant disorders (OPMDs) with dysplasia; 25 patients having OPMDs without dysplasia, and 25 oral cancer patients. Demographic data modified gingival index, oral hygiene level, and salivary levels of the biomarkers were assessed.

RESULTS

Salivary levels of IL-6, IL-8, and sCD44 progressively increased with increased disease severity. Salivary IL-8 and IL-6 levels possess a discriminating potential from normal tissue through different degrees of dysplasia to oral cancer, sCD44 levels had a discriminating power between normal and dysplastic tissues with high sensitivity and specificity. A positive correlation was found between the three biomarkers and the grade of oral squamous cell carcinoma (OSCC) and with different risk factors.

CONCLUSION

This is the first study that evaluated multiple salivary proteomic biomarkers in the Egyptian population, and the results validate the ability of IL-6, IL-8, and sCD44 to be used as sensitive diagnostic and prognostic biomarkers for screening and early detection of oral cancer.

Field Cancerisation in Oral Squamous Cell Carcinoma Patients: A Systematic Review

Introduction

Field cancerisation refers to molecular level cancerous changes that occurs in clinically normal looking tissue. In oral cavity, widespread exposure to carcinogens like tobacco/alcohol makes the entire mucosa susceptible to malignant changes. This manifests as local recurrence and/second primary after initial treatment of primary tumours. The purpose of this review is to identify the most commonly used marker in oral cavity field cancerisation and also to find out its prognostic significance.

Materials and method

Systematic review was conducted following PRISMA guidelines. Literature search was conducted using PubMed, Web of Science and Google scholar. Study selection was done independently by two reviewers and any discrepancy was resolved by third reviewer. A total of 23 articles were included after full-text reading. JBI checklist was used to assess the risk of bias for each study and RevMan 5.4 software was used to develop graphs.

Discussion and conclusion

Ki-67, p53, cyclin-D1, E-Cadherin, vascular markers like α -SMA, mi-RNAs, chromosomal polysomy, and epigenetic modifications like gene methylations were the various biomarkers used in the included studies. Both Ki-67 and p53 were found to be the most commonly employed markers in field cancerisation. However Ki-67 has more confirmed role in identifying field changes and is an established independent prognostic indicator of loco-regional control and disease free- survival rate. Further prospective studies are needed to fully evaluate the role of these markers in predicting second events like loco-regional recurrences and second primaries.

Agent Orange and head and neck cancer: A systematic review and meta-analysis

Objective

To assess the incidence of head and neck cancer in patients exposed to Agent Orange and related dioxins.

Methods

Studies were identified through CINAHL, PubMed, and Scopus. Primary studies were identified through April 2023. Articles were included reporting incidence of head and neck cancer and/or deaths due to head and neck cancer in participants exposed to Agent Orange. Meta-analysis of proportions was conducted to calculate incidence and mortality by primary site in those who were exposed to Agent Orange and for control groups. A comparison of proportions was used to compare rates in exposed and control groups.

Results

Of 1530 unique abstracts screened, 13 studies were included in the systematic review. Of the exposed patients with reported subsites, oral cavity (31.2%), and larynx (14%) were the most common. Of the exposed patients with reported deaths and subsites, oropharynx (0.25%) was the most common primary site in patients who died. The most common subsites of those who were not exposed, oropharynx (0.13%), and larynx (0.16%). Head and neck cancer of all subsites was more common in those exposed to Agent Orange than in unexposed controls (difference 0.061%; 95% confidence interval: 0.04%-0.08%, p < 0.0001).

Conclusions

Our findings suggest that head and neck cancer is more common in those who were exposed to Agent Orange than those who were not. Additionally, individuals exposed to Agent Orange were more likely to die from head and neck cancer. Further investigation is warranted to evaluate subsite-specific outcomes given the limitations of our study design.

The impact of caregiver training on the oral health of people with disabilities: A systematic review

AIMS

This systematic review aimed to assess the impact of oral health training for caregivers of individuals with disabilities.

MATERIALS AND METHODS

A systematic review was conducted using five electronic databases: Medline (PubMed), SciELO, Web of Science, LILACS, and CAFe, adhering to PRISMA guidelines. The PICO strategy was defined as follows: Participants: caregivers of individuals with disabilities; Intervention: training or education in oral health for caregivers; Control: no caregiver training; and Outcomes: evaluating whether oral health training for caregivers improves the oral health of people with disabilities. The study aimed to address the research question: "What is the impact of oral health training for caregivers of individuals with disabilities?" The study was preregistered in PROSPERO (CRD42023416760).

RESULTS

A total of 14 studies were included, with trained caregivers being either staff members or parents, and various disabilities reported, with cerebral palsy being the most prevalent. Caregiver training methods varied, such as instructions on the importance of oral health care, supervised oral hygiene, and demonstration of toothbrushing techniques. Overall, the intervention groups showed an improvement in measures such as to the Gingival Index, Plaque Index, Simplified Oral Hygiene Index, and Gingival Bleeding Index on upon probing. Additionally, improvements were observed in the quality, frequency, and duration of toothbrushing among intervention groups.

CONCLUSION

The findings suggest that oral health training for caregivers has a positive impact on the oral health of individuals with disabilities, potentially leading to better oral health outcomes.

Surgical protocols for oral leukoplakia and precancerous lesions across three different anatomic sites

OBJECTIVE

This systematic review and meta-analysis aimed to compare the risk of recurrence and cancer progression after surgical treatment for oral potentially malignant disorders (OPMD) and precancerous lesions in different anatomical sites.

MATERIALS AND METHODS

A comprehensive search was conducted in nine databases and grey literature. We included randomized controlled trials assessing surgical treatment efficacy for OPMD and precancerous lesions of cervical, vaginal, anal, and penile sites. Excision or ablation surgical treatments were considered.

RESULTS

Overall, 12 studies met the eligibility criteria for oral leukoplakia (OL), proliferative verrucous leukoplakia, cervical intraepithelial neoplasia (CIN), vaginal intraepithelial neoplasia, and anal intraepithelial neoplasia (AIN). In qualitative analysis of surgical protocols, the lack of margin description impacts the clinical outcomes of OL and AIN, and the ablative protocols were heterogeneous in both OPMD and precancerous lesions. No significant difference in OL (risk ratio 0.82 [95% CI: 0.59-1.15]) and CIN (risk ratio 0.31 [95% CI: 0.09-1.09]) for recurrence was observed when cold-knife was compared with ablative protocols. OL exhibited higher recurrence and cancer progression rates compared to CIN and AIN.

CONCLUSION

There is no difference in recurrence risk post-surgical treatment for OL and CIN. Surgical protocols for oral leukoplakia and CIN/AIN lack standardized approaches.

Non-invasive screening for laryngeal cancer using the oral cavity as a proxy for differentiation of laryngeal cancer versus leukoplakia: A novel application of ESS technology and artificial intelligence supported statistical modeling

OBJECTIVE

This preliminary study tested whether non-invasive, remote Elastic Scattering Spectroscopy (ESS) measurements obtained in the oral cavity can be used as a proxy to accurately differentiate between patients with laryngeal cancer versus laryngeal leukoplakia.

METHODS

20 patients with laryngeal lesions [cancer (n = 10),leukoplakia (n = 10)] were clinically assessed and categorized by otolaryngologists per standard clinical practice. Patient demographics of age, race, sex, and smoking history were collected. A machine-learning artificial intelligence (AI) algorithm was applied to classify patients using ESS spectra of patients with benign laryngeal leukoplakia or laryngeal cancer. Specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), F1, and area-under-the-curve (AUC) were calculated. Additional algorithms stratified spectral data by sub-anatomical site and smoking status to explore diagnostic capability.

RESULTS

Overall, the algorithm had a sensitivity = 74 %, specificity = 40 %, PPV = 51 %, NPV = 64 %, F1 = 0.61 and AUC = 0.65. When stratifying by former and active smokers, algorithm sensitivities increased to 85 % and 77 %. Analysis by sub-anatomic location yielded an AUC = 0.77 for lateral tongue, and when stratified by (former/current) smoking status, demonstrated AUC = 0.94 and 0.83, sensitivities = 98 % and 76 %, and specificities = 85 % and 86 %. Algorithm output from the mucosal lip yielded sensitivity = 89 %, specificity = 88 %, PPV = 83 %, and NPV = 92 % in former smokers.

CONCLUSION

This pilot study demonstrated ESS technology coupled with AI-assisted statistical modeling, could differentiate between patients with laryngeal leukoplakia versus cancer with good precision, especially with smoking status and anatomic subclassification. If ESS can be utilized in the oral cavity as a non-invasive screening tool for laryngeal cancer, it would greatly facilitate early detection in specialized/non-specialized clinics, and under-resourced regions.

Genomic alterations in the stepwise progression from normal mucosa to metastasizing oral squamous cell carcinoma

Introduction

The aim of this study was to investigate the genomic changes that occur in the development from dysplasia, cancer and to regional metastases in patients with oral cavity squamous cell carcinoma (OSCC).

Material and methods

We included OSCC patients with lymph node metastases at diagnosis, treated with primary surgery at Rigshospitalet, University of Copenhagen in the period 2007-2014. The resected tumor specimens were evaluated by a pathologist, who marked areas of morphologically normal tissue and dysplasia surrounding the cancer, two areas from the cancer tissue, and one area within the lymph node metastases. From these areas a punch biopsy was taken, and DNA from each sample was extracted and sequenced using Illumina's TSO500 HT cancer panel.

Results

From 51 OSCC patients, 255 samples were included, comprising a wide variety of genomic alterations. Substantial intratumor heterogeneity was found. The most commonly mutated gene was TP53, mutated in 65% of all samples. Only two patients had no TP53 mutation in any samples. We found that morphologically normal appearing mucosa as well as surrounding dysplasia also contained malignant mutations, supporting the theory of field cancerization. There was a significant lower average tumor mutational burden (TMB) in the lymph node metastases compared to the primary tumors, supporting the theory of clonal selection.

Conclusion

Substantial inter- and intratumor genomic heterogeneity was found. Mutation of TP53 was the most common and was present in all but two patients. Our data strongly supports the theory of clonal selection and the theory of field cancerization.

Diseases with oral malignant potential: Need for change to inform research, policy, and practice

This manuscript critically examines the current classification of oral potentially malignant disorders, questioning the practicality and implications of labeling such a large population as precancerous, given that the actual progression to oral cancer is significantly low for most disorders. The paper advocates for a revised classification system that accurately reflects the varying malignancy risks associated with different disorders. It suggests a reassessment of the diagnostic and management approaches to mitigate overdiagnosis and alleviate patient burdens. We propose categorizing diseases with oral malignant potential as follows: Oral Precancerous Diseases, encompassing high-risk lesions and conditions like erythroplakia, non-homogeneous leukoplakia, proliferative leukoplakia, and actinic keratosis; Oral Potentially Premalignant Diseases, covering lesions, conditions, and systemic diseases with distinct oral manifestations harboring a limited or undefined risk of transformation, such as homogeneous leukoplakia, oral submucous fibrosis, oral lichenoid diseases, chronic hyperplastic candidosis, keratosis of known aetiology (smokeless tobacco, khat), palatal lesions in reverse smokers, and dyskeratosis congenita; and Systemic Conditions with Oral Malignant Potential including Fanconi's anemia, xeroderma pigmentosum, and chronic immunosuppression (including patients post-bone marrow transplantation), which are associated with an increased risk of oral cancer without preceding precursor lesions. We provide illustrative examples to demonstrate how this framework offers practical guidance for research, policy-making, and clinical practice.

Clinicopathological risk factors of oral second primary tumours

Background

Oral second primary tumours (SPTs) have a poor prognosis due to late-stage diagnosis. This study evaluates the demographic and clinicopathological risk predictors of SPTs.

Methods

Patients with oral squamous cell carcinoma, carcinoma in situ, or severe dysplasia were accrued into the Oral Cancer Prediction Longitudinal study within one year post-curative treatment. Data on demographics, risk habits, and primary tumour characteristics were collected. Clinical follow-up included assessing the presence of second oral premalignant lesions (SOPLs), clinicopathological features, and the results from toluidine blue staining and fluorescence visualization.

Results

Among 296 patients, 23 (8 %) developed SPTs. Older age at primary cancer diagnosis (P = 0.008) and a history of chewing tobacco or betel nut (P = 0.043) increased the risk of SPTs. Patients with primary tumours located at low-risk sites had an increased risk of SPTs (P = 0.004), which often presented at high-risk sites. The presence of SOPLs (P < 0.001), and multiple lesions (P = 0.017) significantly increased the risk of SPTs. Positive toluidine blue staining indicated a trend toward higher risk of SPTs, whereas fluorescence visualization did not. The median time to SPT diagnosis was 3.25 years post-treatment.

Conclusions

Identifying second or multiple oral premalignant lesions is critical for predicting the risk of SPTs regardless of their clinical or histological characteristics. Routine biopsy of these lesions should be prioritized to ensure timely diagnosis. Incorporating these risk predictors into clinical follow-up can enhance early cancer detection and improve patient outcomes.

Identifying factors related to delayed neck metastasis after surgical treatment in patients with oral squamous cell carcinoma

BACKGROUND

General treatment of oral squamous cell carcinoma (OSCC) is surgical treatment with or without neck dissection. Although the incidence of delayed neck metastasis is rare, it may occur after the surgery and is known to be the most important factor in the prognosis. The purpose of is study is to evaluate the clinical and histopathological factors associated with delayed neck metastasis case among patients.

METHODS

A total of 195 patients who underwent surgical treatment for OSCC from 2016 to 2022 were investigated. Among them, delayed neck metastasis (DNM) was analyzed. The criterion for delayed neck metastasis was a newly developed neck lesion after the primary operation without neck dissection in cN0 necks. To identify the correlation between prognostic factors and the incidence of delayed neck metastasis, χ2 analysis with phi correlation and Cramer's V test was performed. Cumulative survival rates (CRS) were compared between the groups with the incidence of DNM and without DNM. Also, the log rank test for CSR and Cox proportional hazard model was analyzed to estimate the significance of the CSR and confirm the correlations between prognostic factors and DNM.

RESULT

Among 195 patients, 14 were discovered to have DNM. The primary tumor locations were the tongue (n = 5), floor of the mouth (n = 2), mandibular gingiva (n = 1), maxillary gingiva (n = 4), retromolartrigone (n = 1), and buccal mucosa (n = 2) each. The cases consisted of TNM stage I (n = 1), stage II (n = 3), stage III (n = 3), and stage IV (n = 8), respectively. The result of the χ2 analysis identified a correlation between positive neck (p = 0.01), depth of invasion (p = 0.09), radiation therapy (p = 0.003), and DNM. Groups without DNM showed better prognosis compared to groups with DNM. Regarding positive neck, depth of invasion, and radiation therapy, only depth of invasion showed significance in CSR analysis.

CONCLUSION

DNM after surgical treatment of OSCC is a rare event, and few were found in a review of the literature. Also, many prognostic factors have been suggested but controversial. However, in our study, some prognostic factors have been identified to have a significant correlation with the incidence of DNM, and analysis of such factors provides important information predicting neck metastasis and the prognosis.

Differences among oral carcinomas arising de novo from those associated with oral potentially malignant disorders: a systematic review and meta-analysis

OBJECTIVE

To analyze the frequency of sequential oral squamous cell carcinomas (s-OSCC), preceded by oral potentially malignant disorders, and OSCC de novo (OSCC-dn) and explore differences in their clinicopathologic presentations.

STUDY DESIGN

A structured electronic search strategy identified studies that analyzed frequency, clinical, biological, demographic, biomarkers, and prognostic features of s-OSCC and OSCC-dn according to PRISMA guidelines in PubMed, Scopus, Cochrane Library, and Google Scholar, up to January 31, 2023. Inclusion criteria were original English, Spanish, Portuguese, French, Italian, and German cross-sectional, cohort, and case-control studies. The quality of studies was assessed using the Agency for Research and Health Quality tool and the Newcastle-Ottawa Scale tool.

RESULTS

The final selection included 40 studies. OSCC-dn and s-OSCC represent, respectively, 71% and 29% of cases of OSCC (P = .00), showing a higher percentage of T1 or of T1+T2 in s-OSCC (P < .0001). The association meta-analysis showed OSCC-dn with a significant association. The meta-analysis showed that s-OSCC was significantly associated with smaller tumor size, absence of distant metastases, relapses, male sex, and tumor sites different from tongue; and OSCC-dn was associated with more advanced tumor size, more regional and distant metastases, more advanced stages, and worse survival.

CONCLUSIONS

S-OSCC was less frequent than expected. OSCC-dn seems to have specific clinical, biological, and prognostic features. Future perspectives on oral cancer prevention should address novel approaches and alternatives to screening, such as urgent referral of OSCC-dn.

Ex Vivo Analysis of Cell Differentiation, Oxidative Stress, Inflammation, and DNA Damage on Cutaneous Field Cancerization

Cutaneous field cancerization (CFC) refers to a skin region containing mutated cells' clones, predominantly arising from chronic exposure to ultraviolet radiation (UVR), which exhibits an elevated risk of developing precancerous and neoplastic lesions. Despite extensive research, many molecular aspects of CFC still need to be better understood. In this study, we conducted ex vivo assessment of cell differentiation, oxidative stress, inflammation, and DNA damage in CFC samples. We collected perilesional skin from 41 patients with skin cancer and non-photoexposed skin from 25 healthy control individuals. These biopsies were either paraffin-embedded for indirect immunofluorescence and immunohistochemistry stain or processed for proteins and mRNA extraction from the epidermidis. Our findings indicate a downregulation of p53 expression and an upregulation of Ki67 and p16 in CFC tissues. Additionally, there were alterations in keratinocyte differentiation markers, disrupted cell differentiation, increased expression of iNOS and proinflammatory cytokines IL-6 and IL-8, along with evidence of oxidative DNA damage. Collectively, our results suggest that despite its outwardly normal appearance, CFC tissue shows early signs of DNA damage, an active inflammatory state, oxidative stress, abnormal cell proliferation and differentiation.

HOXA1 3'UTR Methylation Is a Potential Prognostic Biomarker in Oral Squamous cell Carcinoma

BACKGROUND

HOXA1 is a prognostic marker and a potential predictive biomarker for radioresistance in head and neck tumors. Its overexpression has been associated with promoter methylation and a worse prognosis in oral squamous cell carcinoma (OSCC) patients. However, opposite outcomes are also described. The effect of the methylation of this gene on different gene regions, other than the promoter, remains uncertain. We investigated the methylation profile at different genomic regions of HOXA1 in OSCC and correlated differentially methylated CpG sites with clinicopathological data.

METHODS

The HOXA1 DNA methylation status was evaluated by analyzing data from The Cancer Genome Atlas and three Gene Expression Omnibus datasets. Significant differentially methylated CpG sites were considered with a |∆β| ≥ 0.10 and a Bonferroni-corrected p-value < 0.01. Differentially methylated CpGs were validated by pyrosequencing using two independent cohorts of 15 and 47 OSCC patients, respectively.

RESULTS

Compared to normal tissues, we found significantly higher DNA methylation levels in the 3'UTR region of HOXA1 in OSCC. Higher methylation levels in tumor samples were positively correlated with smoking habits and patients' overall survival.

CONCLUSIONS

Our findings suggest that HOXA1 gene body methylation is a promising prognostic biomarker for OSCC with potential clinical applications in patient monitoring.

Potential of melatonin to reverse epigenetic aberrations in oral cancer: new findings

It is now an accepted principle that epigenetic alterations cause cellular dyshomeostasis and functional changes, both of which are essential for the initiation and completion of the tumor cycle. Oral carcinogenesis is no exception in this regard, as most of the tumors in the different subsites of the oral cavity arise from the cross-reaction between (epi)genetic inheritance and the huge challenge of environmental stressors. Currently, the biochemical machinery is put at the service of the tumor program, halting the cell cycle, triggering uncontrolled proliferation, driving angiogenesis and resistance to apoptosis, until the archetypes of the tumor phenotype are reached. Melatonin has the ability to dynamically affect the epigenetic code. It has become accepted that melatonin can reverse (epi)genetic aberrations present in oral and other cancers, suggesting the possibility of enhancing the oncostatic capacity of standard multimodal treatments by incorporating this indolamine as an adjuvant. First steps in this direction confirm the potential of melatonin as a countermeasure to mitigate the detrimental side effects of conventional first-line radiochemotherapy. This single effect could produce synergies of extraordinary clinical importance, allowing doses to be increased and treatments not to be interrupted, ultimately improving patients' quality of life and prognosis. Motivated by the urgency of improving the medical management of oral cancer, many authors advocate moving from in vitro and preclinical research, where the bulk of melatonin cancer research is concentrated, to systematic randomized clinical trials on large cohorts. Recognizing the challenge to improve the clinical management of cancer, our motivation is to encourage comprehensive and robust research to reveal the clinical potential of melatonin in oral cancer control. To improve the outcome and quality of life of patients with oral cancer, here we provide the latest evidence of the oncolytic activity that melatonin can achieve by manipulating epigenetic patterns in oronasopharyngeal tissue.

Personalized Medicine in Oral Oncology: Imaging Methods and Biological Markers to Support Diagnosis of Oral Squamous Cell Carcinoma (OSCC): A Narrative Literature Review

For decades, oral squamous cell carcinoma (OSCC) has been one of the most prevalent and mortal cancers worldwide. The gold standard for OSCC diagnosis is still histopathology but this narrative multidisciplinary review has the aim to explore the literature about conventional OSCC prognostic indicators related to the pTNM stage at the diagnosis such as the depth of invasion and the lymphovascular invasion associated with distant metastasis as indicators of poor life expectancy. Despite its multifactorial nature and recognizable precursors, its diagnosis at the early stages is still challenging. We wanted to highlight the importance of the screening as a primary weapon that a stomatologist should consider, intercepting all at-risk conditions and lesions associated with OSCC and its early stages. This narrative review also overviews the most promising imaging techniques, such as CT, MRI, and US-echography, and their application related to clinical and surgical practice, but also the most-investigated prognostic and diagnostic tissue and salivary biomarkers helpful in OSCC diagnosis and prognostic assessment. Our work highlighted remarkable potential biomarkers that could have a leading role in the future. However, we are still far from defining an appropriate and concrete protocol to apply in clinical practice. The hope is that the present and future research will overcome these limitations to benefit patients, clinicians, and welfare.