Diagnostic salivary biomarkers in oral cancer and oral potentially malignant disorders and their relationships to risk factors - A systematic review

Genetic associations between gene polymorphisms on 3p25 and oral squamous cell carcinoma

OBJECTIVES

To evaluate the association of SYN2, PPARG, RAF1, TIMP4, and IQSEC1 polymorphisms in 3p25 with oral squamous cell carcinoma (OSCC) in the Chinese Han population.

SUBJECTS AND METHODS

Genomic DNA was extracted from 494 subjects with or without OSCC. Basic information on the subjects, clinical data, and prognoses were collected. Fifteen candidate single nucleotide polymorphisms (SNPs) were selected and genotyped. The statistical analyses included descriptive statistics, logistic regression, survival, and functional annotation was performed.

RESULTS

IQSEC1-rs2686742 correlated with OSCC occurrence. In addition, RAF1-rs1051208, PPARG-rs10865710, PPARG-rs3856806, IQSEC1-rs2686742, PPARG-rs1175544, IQSEC1-rs9211, and IQSEC1-rs2600322 were significantly associated with the clinical characteristics of patients with OSCC. The log-rank test showed that IQSEC1-rs2600322 may play an important role in the survival of patients with OSCC. The Cox regression analysis suggested that PPARG-rs10865710, PPARG-rs7649970, IQSEC1-rs9211, IQSEC1-rs2600322, and IQSEC1-rs12487715 influenced survival outcomes. The functional annotation indicated that the transcript levels of IQSEC1 were upregulated in head and neck squamous cell carcinoma tissues, whereas PPARG gene transcription was downregulated.

CONCLUSIONS

IQSEC1-rs2686742 may be closely associated with OSCC onset. Multiple SNPs in IQSEC1 and PPARG genes correlated with the clinical characteristics of OSCC, among which PPARG-rs10865710, IQSEC1-rs9211, and IQSEC1-rs2600322 were associated with cancer prognosis.

Shaping the future of oral cancer diagnosis: advances in salivary proteomics

INTRODUCTION

Saliva has gained increasing attention in the quest for disease biomarkers. Because it is a biological fluid that can be collected is an easy, painless, and safe way, it has been increasingly studied for the identification of oral cancer biomarkers. This is particularly important because oral cancer is often diagnosed at late stages with a poor prognosis.

AREAS COVERED

The review addresses the evolution of the experimental approaches used in salivary proteomics studies of oral cancer over the years and outlines advantages and pitfalls related to each one. In addition, examines the current landscape of oral cancer biomarker discovery and translation focusing on salivary proteomic studies. This discussion is based on an extensive literature search (PubMed, Scopus and Google Scholar).

EXPERT OPINION

The introduction of mass spectrometry has revolutionized the study of salivary proteomics. In the future, the focus will be on refining existing methods and introducing powerful experimental techniques such as mass spectrometry with selected reaction monitoring, which, despite their effectiveness, are still underutilized due to their high cost. In addition, conducting studies with larger cohorts and establishing standardized protocols for salivary proteomics are key challenges that need to be addressed in the coming years.

Clinical validation of a saliva-based matrix metalloproteinase-1 rapid strip test for detection of oral cavity cancer

BACKGROUND

We previously identified matrix metalloproteinase-1 (MMP-1) as one of the most promising salivary biomarkers for oral squamous cell carcinoma (OSCC) and developed a sensitive ELISA for MMP-1 with good performance in detection of OSCC using a cohort of 1160 saliva samples.

METHODS

A time-saving rapid strip test (RST) for MMP-1 was developed in this study and its diagnostic performance compared with ELISA using saliva samples from a new cohort of 603 subjects (171 healthy controls, 236 patients with oral potentially malignant disorders, and 196 OSCC patients).

RESULTS

Salivary MMP-1 levels measured using RST and ELISA were highly comparable and both assays could effectively distinguish between OSCC and non-cancerous groups. Similar to ELISA, receiver operating characteristic curve analysis of the MMP-1 RST was effective in identifying patients with OSCC at different oral cavity sites and stages.

CONCLUSIONS

Salivary MMP-1 can be sensitively detected using both RST and ELISA methods. Our newly developed point-of-care MMP-1 RST is a promising in vitro diagnostic device (IVD) that may serve as a novel auxiliary tool in the routine clinical detection and monitoring of OSCC.

Early Detection of Oral Potentially Malignant Disorders: A Review on Prospective Screening Methods with Regard to Global Challenges

Oral cancer is a cancer type that is widely prevalent in low-and middle-income countries with a high mortality rate, and poor quality of life for patients after treatment. Early treatment of cancer increases patient survival, improves quality of life and results in less morbidity and a better prognosis. To reach this goal, early detection of malignancies using technologies that can be used in remote and low resource areas is desirable. Such technologies should be affordable, accurate, and easy to use and interpret. This review surveys different technologies that have the potentials of implementation in primary health and general dental practice, considering global perspectives and with a focus on the population in India, where oral cancer is highly prevalent. The technologies reviewed include both sample-based methods, such as saliva and blood analysis and brush biopsy, and more direct screening of the oral cavity including fluorescence, Raman techniques, and optical coherence tomography. Digitalisation, followed by automated artificial intelligence based analysis, are key elements in facilitating wide access to these technologies, to non-specialist personnel and in rural areas, increasing quality and objectivity of the analysis while simultaneously reducing the labour and need for highly trained specialists.

Validity of nomograms for predicting cancer risk in oral leukoplakia and oral lichen planus

OBJECTIVES

This study assessed the validity of nomograms for predicting malignant transformation (MT) among patients with oral leukoplakia (OL) and oral lichen planus (OLP).

MATERIALS AND METHODS

Two nomograms were identified following a systematic search. Variables to interrogate both nomograms were obtained for a retrospective OL/OLP cohort. Then, the nomograms were applied to estimate MT probabilities twice and their average was used to calculate the discriminatory performance, calibration, and potential net benefit of the models. Subgroup analyses were performed for patients with OL, OLP, and oral epithelial dysplasia.

RESULTS

Predicted probabilities were mostly significantly higher among OL/OLP patients who developed MT compared to those who did not (p = <0.001-0.034). AUC values and Brier scores of the nomograms were 0.644-0.844 and 0.040-0.088 among OL patients and 0.580-0.743 and 0.008-0.072 among OLP patients. Decision curve analysis suggested that the nomograms had some net benefit for risk stratification. However, the models did not best binary dysplasia grading in discriminatory validity and net benefit among patients with OL and oral epithelial dysplasia.

CONCLUSION

Nomograms for predicting MT may have satisfactory validity among patients with OL than OLP, but they do not outperform binary dysplasia grading in risk stratification of OL.

Assessment of salivary levels of ErbB2 in oral squamous cell carcinoma

Introduction

Oral cancer is the sixth-most common cancer globally. The survival rate of oral cancer is 5 years, depending on the stage it is diagnosed. To diagnose in the early stage, specialised tumour markers may assist and also help in improving the survival rate of oral cancer. ErbB2 is a transmembrane cell surface receptor required in signal transduction and an essential part of signalling pathways that take part in controlling the basic cellular processes like cell cycle, migration, metabolism and survival, besides cellular proliferation and differentiation. It is over-expressed in oral squamous cell carcinoma (OSCC) and is directly proportional to the poor prognosis, as it is expressed at a very low concentration in a healthy individual. Due to this, ErbB2 could be used as a diagnostic marker in OSCC. Nowadays, the search for tumour expression in the saliva with the use of salivary biomarkers could aid in the diagnosis of the OSSC.

Aim and Objectives

To assess the expression of ErbB2 in the saliva of patients with oral squamous cell carcinoma by correlating the ErbB2 level in the disease group with the healthy group. To determine the diagnostic significance of ErbB2 in OSCC.

Materials and Methods

The study comprises 20 salivary samples from OSCC patients and 20 salivary samples from healthy individuals. The salivary level of ErbB2 was estimated using Enzyme Linked Immunosorbent Assay. To analyse the data, SPSS (IBM SPSS Statistics for Windows, Version 26.0, Armonk, NY: IBM Corp. Released 2019) is used. The significance level is fixed at 5% (α = 0.05). P value <0.05 is considered to be statistically significant. To compare the mean values of mean and concentration, an unpaired/independent sample t-test was used.

Results

The mean age of OSCC and control were found to be 57 ± 8.13 and 26.6 ± 1.51, respectively. The mean age was compared between OSCC and control by the Chi-square test, and the P value was <0.01, which was found to be statistically significant. The salivary levels of ErbB2 in the OSCC and control groups were measured by an unpaired sample t-test. The mean salivary ErbB2 level in the OSCC group is 3.20 ng/ml ± 0.57, and in the control group, it is 2.43 ng/ml ± 0.13. When a pairwise comparison of ErbB2 concentration was performed between OSCC and control, it showed a statistically significant difference with a P value of 0.007, which is P < 0.05.

Conclusion

The present study has demonstrated an increased salivary expression of ErbB2 in OSCC patients when compared to healthy individuals. This suggests that ErbB2 could aid in the diagnosis of OSCC and could be used as a diagnostic marker in the early detection of oral cancer, a finding that has to be further established with a larger sample size.

Salivary Interleukin Levels in Oral Squamous Cell Carcinoma and Oral Epithelial Dysplasia: Findings from a Sri Lankan Study

The incidence of oral squamous cell carcinoma (OSCC), and its precursor, oral epithelial dysplasia (OED), is on the rise, especially in South Asia. OSCC is the leading cancer in males in Sri Lanka, with >80% diagnosed at advanced clinical stages. Early detection is paramount to improve patient outcome, and saliva testing is a promising non-invasive tool. The aim of this study was to assess salivary interleukins (lL1β, IL6, and IL8) in OSCC, OED and disease-free controls in a Sri Lankan study cohort. A case-control study with OSCC (n = 37), OED (n = 30) patients and disease-free controls (n = 30) was conducted. Salivary lL1β, IL6, and IL8 were quantified using enzyme-linked immuno-sorbent assay. Comparisons between different diagnostic groups and potential correlations to risk factors were assessed. Salivary levels for the three tested interleukins increased from disease-free controls through OED, and were highest in OSCC samples. Furthermore, the levels of IL1β, IL6, and IL8 increased progressively with OED grade. The discrimination between patients (OSCC and OED) and controls, as assessed by AUC of receiver operating characteristic curves, was 0.9 for IL8 (p = 0.0001) and 0.8 for IL6 (p = 0.0001), while IL1β differentiated OSCC from controls (AUC 0.7, p = 0.006). No significant associations were found between salivary interleukin levels and smoking, alcohol, and betel quid risk factors. Our findings suggest that salivary IL1β, IL6, and IL8 are associated with disease severity of OED, and are potential biomarkers for predicting disease progression in OED, and the screening of OSCC.

Evaluation of Salivary Interleukin-6 in Patients with Oral Squamous Cell Carcinoma, Oral Potentially Malignant Disorders, Chronic Periodontitis and in Healthy Controls - A Cross-Sectional Comparative Study

Introduction

Oral squamous cell carcinoma (OSCC) accounts for 95% among all head and neck cancers. Literature reveals saliva as a predictive, diagnostic and prognostic tool in carcinoma, inflammatory and genetic disorders. Expression of salivary interleukin-6 (IL-6) has been reported in patients with OSCC and in oral potentially malignant disorders (OPMDs). This study aims at the following objectives: • To evaluate the changes in the salivary levels of IL-6 in healthy individuals and those with chronic periodontitis (CP), OPMD and OSCC. • To compare the estimated levels of salivary IL-6 individually in healthy individuals and those with CP, OPMD and OSCC. • To assess the estimated levels of salivary IL-6 individually within histopathologically differentiated OSCC. • To analyse salivary IL-6 as a reliable biomarker in the diagnosis of OSCC.

Materials and Methods

Totally, 60 patients were divided into four groups consisting of 15 patients in each group. Salivary samples were collected by simple drooling method. The concentration of IL-6 is to be determined by using Quantitative sandwich ELISA technique. All analyses were carried out using Statistical Package for Social Sciences (SPSS).

Results

The concentration values of IL-6 were found to be more in OSCC group in comparison with the other three groups and the concentration values of OPMD were found to be more than in the CP and control group and was statistically significant.

Discussion

We attempted a study to evaluate the salivary IL-6 in patients with OSCC, OPMDs and CP in comparison with the healthy controls. We achieved a pragmatic result showed that salivary IL-6 can be a reliable biomarker in the detection of OSCC. Saliva, due its wide array of functional characteristics, is an upcoming diagnostic fluid in the field of medicine and salivary IL-6 can be one such biomarker in the diagnosis of OSCC.

The Use of Salivary Levels of Matrix Metalloproteinases as an Adjuvant Method in the Early Diagnosis of Oral Squamous Cell Carcinoma: A Narrative Literature Review

Oral squamous cell carcinoma (OSCC) is an aggressive malignancy with increased mortality, in which the early diagnosis is the most important step in increasing patients' survival rate. Extensive research has evaluated the role of saliva as a source of diagnostic biomarkers, among which matrix metalloproteinases (MMPs) have shown a valuable potential for detecting even early stages of OSCC. The aim of this review was to present recent clinical data regarding the significance of salivary MMPs in the detection of early malignant transformation of the oral mucosa. A narrative review was conducted on articles published in PubMed, Cochrane Library, Web of Science, EBSCO and SciELO databases, using specific terms. Our search revealed that MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, MMP-12 and MMP-13 had significantly higher levels in saliva from patients with OSCC compared to controls. However, the strength of evidence is limited, as most information regarding their use as adjuvant diagnostic tools for OSCC comes from studies with a low number of participants, variable methodologies for saliva sampling and diagnostic assays, and insufficient adjustment for all covariates. MMP-1, MMP-3 and MMP-9 were considered the most promising candidates for salivary diagnosis of OSCC, but larger studies are needed in order to validate their clinical application.

PLCE1 as a diagnostic and prognostic biomarker by promoting the growth and progression of oral squamous cell carcinoma

OBJECTIVE

This study aimed to explore the role of phospholipase C epsilon1 (PLCE1) in the growth and progression of oral squamous cell carcinoma (OSCC) and determine its potential as a biomarker with respect to diagnosis, prognosis and treatment of OSCC.

METHODS

The expression level of PLCE1 in tissue specimens was detected by immunohistochemistry (182 OSCC cases and 76 controls) and its relationship to clinicopathological parameters was analyzed. Then, the diagnostic value of PLCE1 in OSCC was verified by constructing the receiver operating characteristic (ROC) curve. Kaplan-Meier and Cox analysis were performed to investigate the role of PLCE1 in predicting the prognosis of OSCC patients. Furthermore, the effects of PLCE1 on the occurrence and development of OSCC were revealed by knocking down the level of PLCE1.

RESULTS

PLCE1 was mainly located in the cytoplasm of OSCC cells, and its level in OSCC tissues was obviously higher than in adjacent normal tissues. While the expression of PLCE1 did not correlate with clinicopathological parameters of OSCC. The area under the ROC curve (AUC) of PLCE1 was 0.865 with a sensitivity of 75.8% and a specificity of 78.8%. Besides, high expression of PLCE1 suggested a worse prognosis in OSCC patients than those with low expression. The knockdown of PLCE1 obviously inhibited proliferation, migration, and invasion of OSCC cells, and induce G0 cell cycle phase arrest and apoptosis, thus preventing the progression of OSCC.

CONCLUSION

PLCE1 may cause carcinogenesis and development of OSCC, which provide a novel possibility in diagnosis, prognosis and treatment of OSCC. This article is protected by copyright. All rights reserved.

Multifunctional photodynamic/photothermal nano-agents for the treatment of oral leukoplakia

Oral leukoplakia (OLK) has gained extensive attention because of the potential risk for malignant transformation. Photosensitizers (PSs) played an indispensable role in the photodynamic therapy (PDT) of OLK, but the poor light sensitivity greatly hampered its clinical application. Herein, a novel organic photosensitive ITIC-Th nanoparticles (ITIC-Th NPs) were developed for OLK photodynamic/photothermal therapy (PTT). ITIC-Th NPs present both high photothermal conversion efficiency (~ 38%) and suitable reactive oxygen species (ROS) generation ability under 660 nm laser irradiation, making them possess excellent PDT and PTT capability. In 4-nitroquinoline 1-oxide (4NQO)-induced oral precancerous animal models, ITIC-Th NPs effectively suppress the OLK's cancerization without apparent topical or systemic toxicity in vivo. This study offers a promising therapeutic strategy for PDT and PTT in OLK treatment, and this study is the first interdisciplinary research in the field of multimodal therapy for OLK.

Development and validation of a nomogram prediction model for malignant transformation of oral potentially malignant disorders

OBJECTIVE

Oral potentially malignant disorders have increased the risk of oral squamous cell carcinoma. This study developed a nomogram model to assess the risks of malignant transformation of oral potentially malignant disorders.

MATERIALS AND METHODS

A retrospective analysis of patients diagnosed with oral potentially malignant disorders confirmed by pre-treatment biopsy was performed between 2010 and 2017 at the Peking University Hospital of Stomatology. The candidate risk factors for malignant transformation were screened from clinicopathological variables using Cox and stepwise regression analyses. The nomogram model was constructed based on the regression results and was validated through receiver operating characteristic curves and calibration curves. Decision curve analysis was used to estimate clinical usefulness.

RESULTS

A total of 6964 cases of oral potentially malignant disorders were assessed. The malignant transformation rate of oral potentially malignant disorders was 2.00%. Risk factors (age, site, kind of oral potentially malignant disorder, existence of dysplasia and its grade, and other cancers) derived from the regression analyses were entered into the nomogram model. Time-dependent receiver operating characteristic curve, calibration curve, and decision curve analyses showed high levels of predictive value and clinical relevance, although not for all oral potentially malignant disorders.

CONCLUSION

A specific dynamic nomogram could be adopted to predict the malignant transformation of oral potentially malignant disorders and implement interventions.