Concomitant analysis of salivary tumor markers--a new diagnostic tool for oral cancer

Identification of CT based radiomic biomarkers for progression free survival in head and neck squamous cell carcinoma

This study addresses the limited noninvasive tools for Head and Neck Squamous Cell Carcinoma (HNSCC) progression-free survival (PFS) prediction by identifying Computed Tomography (CT)-based biomarkers for predicting prognosis. A retrospective analysis was conducted on data from 203 HNSCC patients. An ensemble feature selection involving correlation analysis, univariate survival analysis, best-subset selection, and the LASSO-Cox algorithm was used to select functional features, which were then used to build final Cox Proportional Hazards models (CPH). Our CPH achieved a 0.69 concordance index in an external indepedent cohort of 77 patients. The model identified five CT-based radiomics features, Gradient ngtdm Contrast, Logσ=33D-FirstorderRootMeanSquared, Logσ=0.13D-glszm SmallAreaLowGrayLevelEmphasis, Exponential-gldm LargeDependenceHighGrayLevelEmphasis, and Gradient ngtdm Strength as survival biomarkers (p-value < 0.05). These findings contribute to our knowledge of how radiomics can be used to predict the outcome so that treatment plans can be tailored for people with HNSCC to improve their prognosis.

The expression of salivary EGF, VEGF, endothelin, and transferrin in waterpipe and cigarette smokers

The aim of this study was to evaluate the effects of two forms of tobacco smoking, cigarettes and water pipe smoking (WPS), on the expression of a panel of salivary proteins in healthy adults. Three groups of age and gender-matched participants were enrolled in the study: never-smokers, cigarette smokers and WPS (N = 55 per group). Expression of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), endothelin and transferrin in unstimulated whole saliva was estimated using enzyme-linked immunosorbent assays. Statistical analysis consisted of one-way ANOVA and Tukey's post hoc tests, in addition to bioinformatics analysis. VEGF expression was the least in WPS (51.1 ± 14.5 pg/ml) compared to both controls (150.1 ± 13.8 pg/ml) and cigarette smokers (93 ± 9.9 pg/ml), with a significant difference in WPS (p < 0.001) and cigarette smokers (p < 0.01) compared to controls. Furthermore, transferrin showed the weakest expression in the WPS group (1238 ± 261.4 pg/ml) compared to controls (2205.6 ± 298.6 pg/ml) (p = 0.05) and cigarette smokers (1805.4 ± 244 pg/ml). Neither EGF nor endothelin expression showed any statistical difference between the groups (p > 0.05). Gene-gene interaction network demonstrated that FLT1, TFRC, KDR, VEGFB and PGF genes had the highest potential for interaction with the studied proteins. Further functional annotations on the identified markers in the interaction network were performed to identify HIF-1 pathways among the most relevant pathways. In conclusion, smoking habits alter the expression of salivary VEGF and transferrin, which may correspond to early sub-clinical changes in the oral mucosa. The clinical relevance of these salivary changes requires further research.

Rosini Silva A, Brites C, Angelo da Silva Miyaguti N, Raposo Passos Mansoldo F, Vaz Nunes S, Henrique Godoy Sanches P, Regiani Cataldi T, Pais de Carvalho C, Reis da Silva A, Ribeiro da Rosa J, Magalhães Borges M, Vilarindo Oliveira W, Canevari TC, Beatriz Vermelho A, Nogueira Eberlin M, M. Porcari A. Mass Spectrometry-Based Metabolomics Reveals a Salivary Signature for Low-Severity COVID-19

Omics approaches were extensively applied during the coronavirus disease 2019 (COVID-19) pandemic to understand the disease, identify biomarkers with diagnostic and prognostic value, and discover new molecular targets for medications. COVID-19 continues to challenge the healthcare system as the virus mutates, becoming more transmissible or adept at evading the immune system, causing resurgent epidemic waves over the last few years. In this study, we used saliva from volunteers who were negative and positive for COVID-19 when Omicron and its variants became dominant. We applied a direct solid-phase extraction approach followed by non-target metabolomics analysis to identify potential salivary signatures of hospital-recruited volunteers to establish a model for COVID-19 screening. Our model, which aimed to differentiate COVID-19-positive individuals from controls in a hospital setting, was based on 39 compounds and achieved high sensitivity (85%/100%), specificity (82%/84%), and accuracy (84%/92%) in training and validation sets, respectively. The salivary diagnostic signatures were mainly composed of amino acids and lipids and were related to a heightened innate immune antiviral response and an attenuated inflammatory profile. The higher abundance of thyrotropin-releasing hormone in the COVID-19 positive group highlighted the endocrine imbalance in low-severity disease, as first reported here, underscoring the need for further studies in this area.

A review: early detection of oral cancer biomarkers using microfluidic colorimetric point-of-care devices

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck cancers. OSCC constitutes 90% of the head and neck malignancies. The delayed identification of oral cancer is the primary cause of ineffective medical treatment. To address this issue, low-cost, reliable point-of-care devices that can be utilized for large-scale screening, even in low-resource settings, including rural areas and primary healthcare centers, are of great interest. Herein, a comprehensive analysis of numerous salivary biomarkers that exhibit significant variations in concentration between individuals with oral cancer and those without is given. Furthermore, the article explores several point-of-care devices that exhibit potential in the realm of oral cancer detection. The biomarkers are discussed with a focus on their structural characteristics and role in oral cancer progression. The devices based on colorimetry and microfluidics are discussed in detail, considering their compliance with the 'REASSURED' criteria given by the World Health Organization (WHO) and suitability for mass screening in low-resource settings. Finally, the discourse revolves around the fundamental aspects pertaining to the advancement of multiplex, cost-effective point-of-care devices designed for widespread screening purposes.

Synergistic Assembly of 1DZnO and Anti-CYFRA 21-1: A Physicochemical Approach to Optical Biosensing

Objective: We conducted a comprehensive physicochemical analysis of one-dimensional ZnO nanowires (1DZnO), incorporating anti-CYFRA 21-1 immobilization to promote fast optical biomarker detection up to 10 ng ml-1. Impact Statement: This study highlights the effectiveness of proof-of-concept 1DZnO nanoplatforms for rapid cancer biomarker detection by examining the nanoscale integration of 1DZnO with these bioreceptors to deliver reliable photoluminescent output signals. Introduction: The urgent need for swift and accurate prognoses in healthcare settings drives the rise of sensitive biosensing nanoplatforms for cancer detection, which has benefited from biomarker identification. CYFRA 21-1 is a reliable target for the early prediction of cancer formation that can be perceptible in blood, saliva, and serum. However, 1DZnO nanostructures have been barely applied for CYFRA 21-1 detection. Methods: We assessed the nanoscale interaction between 1DZnO and anti-CYFRA 21-1 antibodies to develop rapid CYFRA 21-1 detection in two distinct matrices: PhosphateBuffered Saline (PBS) buffer and artificial saliva. The chemical modifications were tracked utilizing Fourier transform infrared spectroscopy, while transmission electron microscopy and energy dispersive spectroscopy confirmed antigen-antibody interplay over nanostructures. Results: Our results show high antibody immobilization efficiencies, affirming the effectiveness of 1DZnO nanoplatforms for rapid CYFRA 21-1 testing within a 5-min detection window in both PBS and artificial saliva. Photoluminescence measurements also revealed distinct optical responses across biomarker concentrations ranging from 10 to 1,000 ng ml-1. Conclusion: Discernible PL signal responses obtained after 5 min affirm the potential of 1DZnO nanoplatforms for further advancement in optical biomarker detection for application in early cancer prognosis.

CXCL14 and miR-4484 serves as potential salivary biomarkers for early detection of peri-implantitis

Peri-implantitis develops in 43.3% of implant patients, which affects tissues around the implant that may ultimately cause implant loss if not treated properly. Due to difficulties in detecting peri-implantitis in its early phases, implant failures are constantly on the rise. Therefore, new specific molecular markers need to be identified to prevent or limit disease progression in peri-implantitis patients. We investigated levels of CXCL9, CXCL12, and CXCL14 in saliva samples of 45 patients with commercially pure grade 4/5 Titanium-Aluminum-Vanadium implants. We analyzed the correlation of the chemokine levels using Pearson's Correlation test and investigated their power to discriminate peri-implantitis vs. non-peri-implantitis patients using receiver operating characteristic analysis. Our in silico investigation revealed CXCL9, CXCL12, and CXCL14 as predicted targets of miR-4484, which has been demonstrated as a powerful biomarker candidate for early detection of peri-implantitis in our previous study. We measured high CXCL9 and low CXCL14 levels in the saliva of peri-implantitis patients. We also reported that the CXCL14 level showed a significant positive correlation with miR-4484. Besides, CXCL14 together with miR-4484 in saliva differentiated peri-implantitis patients from non-peri-implantitis individuals with 100% success. We offer differential expressions of CXCL14 and miR-4484 in the saliva of patients with peri-implantitis as potential salivary biomarkers for early detection of this disease.

A simple and effective method for smartphone-based detection of polyamines in oral cancer

Oral cancer accounts for 50%-70% of all cancer-related deaths in India and ranks sixth among the most frequent cancers globally. Roughly 90% of oral malignancies are histologically arise from squamous cells and are therefore called oral squamous cell carcinoma. Organic polycations known as biogenic polyamines, for example, putrescine (Put), spermidine (Spd), and spermine (Spm), are vital for cell proliferation, including gene expression control, regulation of endonuclease-mediated fragmentation of DNA, and DNA damage inhibition. Higher Spm and Spd levels have been identified as cancer biomarkers for detecting tumour development in various cancers. The current study utilises tannic acid, a polyphenolic compound, as a reducing and capping agent to fabricate AuNPs via a one-step microwave-assisted synthesis. The fabricated TA@AuNPs were utilised as a nanoprobe for colourimetric sensing of polyamines in PBS. When TA@AuNPs are added to the polyamine, the amine groups in polyamines interact with the phenolic groups of TA@AuNPs via hydrogen bonding or electrostatic interactions. These interactions cause the aggregation of TA@AuNPs, resulting in a red shift of the Surface Plasmon Resonance band of TA@AuNPs from 530 nm to 560 nm. The nanoprobe was found to be highly specific for Spm at low concentrations. TA@AuNPs were able to detect Spm successfully in artificial saliva samples. On recording the RGB values of the sensing process using a smartphone app, it was found that as the nanoparticles aggregated due to the presence of Spm, the intensity of theR-value decreased, indicating the aggregation of TA@AuNPs due to interaction with the polyamine.

Salivary biomarkers: The early diagnosis of Alzheimer's disease

The precise identification of Alzheimer's disease and other prevalent neurodegenerative diseases remains a difficult issue that requires the development of early detection of the disease and inexpensive biomarkers that can replace the present cerebrospinal fluid and imaging biomarkers. Blood biomarkers, such as amyloid and neurofilament light, have been emphasized as an important and practical tool in a testing or examination procedure thanks to advancements in ultra-sensitive detection techniques. Although saliva is not currently being researched for neurodegenerative diseases, it is an important source of biomarkers that can be used for the identification of diseases and has some advantages over other biofluids. While this may be true for most people, getting saliva from elderly people presents some significant challenges. In this overview, we will first discuss how saliva is created and how aging-related illnesses may affect the amount and kind of saliva produced. The findings support the use of salivary amyloid protein, tau species, and novel biomarkers in the diagnosis of Alzheimer's disease.

Identification of CT-based non-invasive radiomic biomarkers for overall survival prediction in oral cavity squamous cell carcinoma

This study addresses the limited non-invasive tools for Oral Cavity Squamous Cell Carcinoma (OSCC) survival prediction by identifying Computed Tomography (CT)-based biomarkers to improve prognosis prediction. A retrospective analysis was conducted on data from 149 OSCC patients, including CT radiomics and clinical information. An ensemble approach involving correlation analysis, score screening, and the Sparse-L1 algorithm was used to select functional features, which were then used to build Cox Proportional Hazards models (CPH). Our CPH achieved a 0.70 concordance index in testing. The model identified two CT-based radiomics features, Gradient-Neighboring-Gray-Tone-Difference-Matrix-Strength (GNS) and normalized-Wavelet-LLL-Gray-Level-Dependence-Matrix-Large-Dependence-High-Gray-Level-Emphasis (HLE), as well as stage and alcohol usage, as survival biomarkers. The GNS group with values above 14 showed a hazard ratio of 0.12 and a 3-year survival rate of about 90%. Conversely, the GNS group with values less than or equal to 14 had a 49% survival rate. For normalized HLE, the high-end group (HLE > - 0.415) had a hazard ratio of 2.41, resulting in a 3-year survival rate of 70%, while the low-end group (HLE ≤ - 0.415) had a 36% survival rate. These findings contribute to our knowledge of how radiomics can be used to predict the outcome so that treatment plans can be tailored for patients people with OSCC to improve their survival.

Identification of CT-based non-invasive Radiographic Biomarkers for Overall Survival Stratification in Oral Cavity Squamous Cell Carcinoma

This study addresses the limited non-invasive tools for Oral Cavity Squamous Cell Carcinoma OSCC survival prediction by identifying Computed Tomography (CT)-based biomarkers for improved prognosis. A retrospective analysis was conducted on data from 149 OSCC patients, including radiomics and clinical. An ensemble approach involving correlation analysis, score screening, and the Sparse-L1 algorithm was used to select functional features, which were then used to build Cox Proportional Hazards models (CPH). Our CPH achieved a 0.70 concordance index in testing. The model identified two CT-based radiomics features, Gradient-Neighboring-Gray-Tone-Difference-Matrix-Strength (GNS) and normalized-Wavelet-LLL-Gray-Level-Dependence-Matrix-Large-Dependence-High-Gray-Level-Emphasis (HLE), as well as smoking and alcohol usage, as survival biomarkers. The GNS group with values above 14 showed a hazard ratio of 0.12 and a 3-year survival rate of about 90%. Conversely, the GNS group with values less than or equal to 14 had a 49% survival rate. For normalized HLE, the high-end group (HLE > -0.415) had a hazard ratio of 2.41, resulting in a 3-year survival rate of 70%, while the low-end group (HLE <= -0.415) had a 36% survival rate. These findings contribute to our knowledge of how radiomics can be used to anticipate the outcome and tailor treatment plans from people with OSCC.

A systematic review on the role of biomarkers in liquid biopsies and saliva samples in the monitoring of salivary gland cancer

BACKGROUND

Salivary gland cancer is a rare disease, and approximately 20% of tumors in the salivary glands are malignant. Reliable biomarkers may have a role in monitoring salivary gland cancer.

AIM

To review the current literature on the role of biomarkers in liquid biopsies and saliva samples in the monitoring of salivary gland cancer.

MATERIALS AND METHOD

This study systematically reviewed the literature on studies detecting salivary gland cancer by biomarkers in liquid biopsies and saliva samples by systematically searching PubMed and Embase between 1 January 2013 and 7 March 2023.

RESULTS

Five studies covering 64 malignant cases of salivary gland cancer were included, which considered inflammatory biomarkers or markers of genetic material in either blood or saliva. In saliva, there were demonstrated elevations of CA-19-9 in malignant cases, and elevations of miRNA in malignant and benign cases. In blood, there were demonstrated elevations of IL-33 in malignant and benign cases, elevations of ctDNA in malignant cases, and elevations of CTC in malignant cases.

CONCLUSION AND SIGNIFICANCE

The studies indicate that there is potential in the detection method. The studies detecting genetic material by liquid biopsies showed the most promising results. At present, there is still progression to be made before the method can be implemented for diagnostic use.

Review Insights on Salivary Proteomics Biomarkers in Oral Cancer Detection and Diagnosis

Early detection is crucial for the treatment and prognosis of oral cancer, a potentially lethal condition. Tumor markers are abnormal biological byproducts produced by malignant cells that may be found and analyzed in a variety of bodily fluids, including saliva. Early detection and appropriate treatment can increase cure rates to 80-90% and considerably improve quality of life by reducing the need for costly, incapacitating medicines. Salivary diagnostics has drawn the interest of many researchers and has been proven to be an effective tool for both medication monitoring and the diagnosis of several systemic diseases. Since researchers are now searching for biomarkers in saliva, an accessible bodily fluid, for noninvasive diagnosis of oral cancer, measuring tumor markers in saliva is an interesting alternative to blood testing for early identification, post-treatment monitoring, and monitoring high-risk lesions. New molecular markers for oral cancer detection, treatment, and prognosis have been found as a result of developments in the fields of molecular biology and salivary proteomics. The numerous salivary tumor biomarkers and how they relate to oral cancer and pre-cancer are covered in this article. We are optimistic that salivary protein biomarkers may one day be discovered for the clinical detection of oral cancer because of the rapid advancement of proteomic technology.

Strategies for Improving Transdermal Administration: New Approaches to Controlled Drug Release

In this work, we aim to address several strategies to improve transdermal drug delivery, such as iontophoresis, sonophoresis, electroporation and micron. We also propose a review of some transdermal patches and their applications in medicine. TDDs (transdermal patches with delayed active substances) are multilayered pharmaceutical preparations that may contain one or more active substances, of which, systemic absorption is achieved through intact skin. The paper also presents new approaches to the controlled release of drugs: niosomes, microemulsions, transfersomes, ethosomes, but also hybrid approaches nanoemulsions and microns. The novelty of this review lies in the presentation of strategies to improve the transdermal administration of drugs, combined with their applications in medicine, in light of pharmaceutical technological developments.

NMR-Based Metabolomics Demonstrates a Metabolic Change during Early Developmental Stages from Healthy Infants to Young Children

The present study aims to identify the salivary metabolic profile of healthy infants and young children, and to correlate this with age, salivary gland maturation, and dentition. Forty-eight children were selected after clinical evaluation in which all intraoral structures were examined. Total unstimulated saliva was collected, and salivary metabolites were analyzed by 1H Nuclear Magnetic Resonance (NMR) at 25 °C. Partial least squares discriminant analysis (PLS-DA), orthogonal PLS-DA (O-PLS-DA), and univariate analysis were used, adopting a 95% confidence interval. The study showed a distinct salivary metabolomic profile related to age and developmental phase. The saliva of children in the pre-eruption teeth period showed a different metabolite profile than that of children after the eruption. However, more evident changes were observed in the saliva profile of children older than 30 months. Alanine, choline, ethanol, lactate, and sugar region were found in higher levels in the saliva of patients before 30 months old. Acetate, N-acetyl sugar, butyrate, caproate, creatinine, leucine, phenylalanine, propionate, valine, succinate, and valerate were found to be more abundant in the saliva of children after 30 months old. The saliva profile is a result of changes in age and dental eruption, and these findings can be useful for monitoring the physiological changes that occur in infancy.

Opal photonic crystal-enhanced upconversion turn-off fluorescent immunoassay for salivary CEA with oral cancer

The point-of-care test of tumor markers in saliva with high specificity and sensitivity for early diagnosis of oral cancer is of great interest and significance, but remaining a daunting challenge due to the low concentration of such biomarkers in oral fluid. Herein, a turn-off biosensor based on opal photonic crystal (OPC) enhanced upconversion fluorescence is proposed to detect the carcinoembryonic antigen (CEA) in saliva by applying fluorescence resonance energy transfer sensing strategy. Hydrophilic PEI ligands are modified on upconversion nanoparticles to enhance the sensitivity of biosensor by promoting sufficient contact between saliva and detection region. As a substrate for the biosensor, OPC can also provide a local-field effect for greatly enhanced upconversion fluorescence by coupling the stop band and excitation light, and a 66-fold amplification of the upconversion fluorescence signal was obtained. For the CEA detection in spiked saliva, such sensors showed a favorable linear relationship at 0.1-2.5 ng mL^-1 and more than 2.5 ng mL^-1, respectively. The limit of detection was down to 0.1 ng mL^-1. Moreover, by monitoring real saliva, the effective discrepancy between patients and healthy people was confirmed, indicating remarkable practical application value in clinical early diagnosis and home-based self-monitoring of tumors.

Microneedles: structure, classification, and application in oral cancer theranostics

Oral cancer is a malignant tumor that threatens the health of individuals on a global scale. Currently available clinical treatment methods, including surgery, radiotherapy, and chemotherapy, significantly impact the quality of life of patients with systemic side effects. In the treatment of oral cancer, local and efficient delivery of antineoplastic drugs or other substances (like photosensitizers) to improve the therapy effect is a potential way to optimize oral cancer treatments. As an emerging drug delivery system in recent years, microneedles (MNs) can be used for local drug delivery, offering the advantages of high efficiency, convenience, and noninvasiveness. This review briefly introduces the structures and characteristics of various types of MNs and summarizes MN preparation methods. An overview of the current research application of MNs in different cancer treatments is provided. Overall, MNs, as a means of transporting substances, demonstrate great potential in oral cancer treatments, and their promising future applications and perspectives of MNs are outlined in this review.

Current advances in noninvasive methods for the diagnosis of oral squamous cell carcinoma: a review

Oral squamous cell carcinoma (OSCC), one of the most common types of cancers worldwide, is diagnosed mainly through tissue biopsy. However, owing to the tumor heterogeneity and other drawbacks, such as the invasiveness of the biopsy procedure and high cost and limited usefulness of longitudinal surveillance, there has been a focus on adopting more rapid, economical, and noninvasive screening methods. Examples of these include liquid biopsy, optical detection systems, oral brush cytology, microfluidic detection, and artificial intelligence auxiliary diagnosis, which have their own strengths and weaknesses. Extensive research is being performed on various liquid biopsy biomarkers, including novel microbiome components, noncoding RNAs, extracellular vesicles, and circulating tumor DNA. The majority of these elements have demonstrated encouraging clinical outcomes in early OSCC detection. This review summarizes the screening methods for OSCC with a focus on providing new guiding strategies for the diagnosis of the disease.

Nano-diagnostics as an emerging platform for oral cancer detection: Current and emerging trends

Globally, oral cancer kills an estimated 150,000 individuals per year, with 300,000 new cases being diagnosed annually. The high incidence rate of oral cancer among the South-Asian and American populations is majorly due to overuse of tobacco, alcohol, and poor dental hygiene. Additionally, socio-economic issues and lack of general awareness delay the primary screening of the disease. The availability of early screening techniques for oral cancer can help in carving out a niche for accurate disease prognosis and also its prevention. However, conventional diagnostic approaches and therapeutics are still far from optimal. Thus, enhancing the analytical performance of diagnostic platforms in terms of specificity and precision can help in understanding the disease progression paradigm. Fabrication of efficient nanoprobes that are sensitive, noninvasive, cost-effective, and less labor-intensive can reduce the global cancer burden. Recent advances in optical, electrochemical, and spectroscopy-based nano biosensors that employ noble and superparamagnetic nanoparticles, have been proven to be extremely efficient. Further, these sensitive nanoprobes can also be employed for predicting disease relapse after chemotherapy, when the majority of the biomarker load is eliminated. Herein, we provide the readers with a brief summary of conventional and new-age oral cancer detection techniques. A comprehensive understanding of the inherent challenges associated with conventional oral cancer detection techniques is discussed. We also elaborate on how nanoparticles have shown tremendous promise and effectiveness in radically transforming the approach toward oral cancer detection. This article is categorized under: Diagnostic Tools > Biosensing Diagnostic Tools > Diagnostic Nanodevices Diagnostic Tools > In Vitro Nanoparticle-Based Sensing.

Gold nanorod-based multiplex bioanalytical assay for the detection of CYFRA 21-1 and CA-125: towards oral cancer diagnostics

The study emphasizes the application of gold nanorods (GNRs) with different aspect ratios (ARs) for the development of multiplex assay for oral cancer detection. The tunable optical properties of the GNRs that rely on the geometrical alterations of the nanostructure and the corresponding change in the refractive indices of the local environment form the basis of the label-free biosensing mechanism. In the present work, two GNRs with AR 2.1 and AR 3.9 exhibiting LSPR at 620 and 775 nm were used for sensing oral cancer biomarkers (Cyfra 21-1 and CA-125). Clinically relevant salivary concentrations of CYFRA 21-1 and CA-125 were taken into consideration for designing the assay range. Herein, the antibodies against Cyfra 21-1 and CA-125 have been employed as biospecific probes to functionalize the GNRs with different ARs. Molecular interactions that induce a spectral shift of distinct plasmon band maxima facilitated quantitative assessment of the target analyte. The GNR bioprobe employed for sensing Cyfra 21-1 had a wide linear detection range of 0.496-48.4 ng mL^-1 with a detection limit as low as 0.84 ng mL^-1 and for CA-125 the detection range was 5-320 U mL^-1 with a detection limit of 1.6 U mL^-1. The individual GNR bioprobe also showed high specificity against several interferents. For multiplexed biosensing, the plasmon spectra of the GNR bioprobe mixture showed distinct responses upon binding of single and dual targets in the sample mixture and/or artificial saliva. The quantitative data from the developed method are of high clinical significance that can aid in the understanding of clinicopathological advancements in oral cancer at an early stage. This simple yet novel nanosized optical transducer technology can be further converted into miniaturized biochips and can be deployed in clinics as a nanoparticle-based point-of-care diagnostic adjunct.

Liquid Biopsy and Circulating Biomarkers for the Diagnosis of Precancerous and Cancerous Oral Lesions

Oral cancer is one of the most common malignancies worldwide, accounting for 2% of all cases annually and 1.8% of all cancer deaths. To date, tissue biopsy and histopathological analyses are the gold standard methods for the diagnosis of oral cancers. However, oral cancer is generally diagnosed at advanced stages with a consequent poor 5-year survival (~50%) due to limited screening programs and inefficient physical examination strategies. To address these limitations, liquid biopsy is recently emerging as a novel minimally invasive tool for the early identification of tumors as well as for the evaluation of tumor heterogeneity and prognosis of patients. Several studies have demonstrated that liquid biopsy in oral cancer could be useful for the detection of circulating biomarkers including circulating tumor DNA (ctDNA), microRNAs (miRNAs), proteins, and exosomes, thus improving diagnostic strategies and paving the way to personalized medicine. However, the application of liquid biopsy in oral cancer is still limited and further studies are needed to better clarify its clinical impact. The present manuscript aims to provide an updated overview of the potential use of liquid biopsy as an additional tool for the management of oral lesions by describing the available methodologies and the most promising biomarkers.

Emerging Biosensors for Oral Cancer Detection and Diagnosis—A Review Unravelling Their Role in Past and Present Advancements in the Field of Early Diagnosis

Oral cancer is a serious concern to people all over the world because of its high mortality rate and metastatic spread to other areas of the body. Despite recent advancements in biomedical research, OC detection at an early stage remains a challenge and is complex and inaccurate with conventional diagnostics procedures. It is critical to study innovative approaches that can enable a faster, easier, non-invasive, and more precise diagnosis of OC in order to increase the survival rate of patients. In this paper, we conducted a review on how biosensors might be an excellent tool for detecting OC. This review covers the strategies that use different biosensors to target various types of biomarkers and focuses on biosensors that function at the molecular level viz. DNA biosensors, RNA biosensors, and protein biosensors. In addition, we reviewed non-invasive electrochemical methods, optical methods, and nano biosensors to analyze the OC biomarkers present in body fluids such as saliva and serum. As a result, this review sheds light on the development of ground-breaking biosensors for the early detection and diagnosis of OC.

On the Cutting Edge of Oral Cancer Prevention: Finding Risk-Predictive Markers in Precancerous Lesions by Longitudinal Studies

Early identification and management of precancerous lesions at high risk of developing cancers is the most effective and economical way to reduce the incidence, mortality, and morbidity of cancers as well as minimizing treatment-related complications, including pain, impaired functions, and disfiguration. Reliable cancer-risk-predictive markers play an important role in enabling evidence-based decision making as well as providing mechanistic insight into the malignant conversion of precancerous lesions. The focus of this article is to review updates on markers that may predict the risk of oral premalignant lesions (OPLs) in developing into oral squamous cell carcinomas (OSCCs), which can logically be discovered only by prospective or retrospective longitudinal studies that analyze pre-progression OPL samples with long-term follow-up outcomes. These risk-predictive markers are different from those that prognosticate the survival outcome of cancers after they have been diagnosed and treated, or those that differentiate between different lesion types and stages. Up-to-date knowledge on cancer-risk-predictive markers discovered by longitudinally followed studies will be reviewed. The goal of this endeavor is to use this information as a starting point to address some key challenges limiting our progress in this area in the hope of achieving effective translation of research discoveries into new clinical interventions.

Detection of inaccessible head and neck lesions using human saliva and fluorescence spectroscopy

Head and neck cancer detection using fluorescence spectroscopy from human saliva is reported here. This study has been conducted on squamous cell carcinoma (SCC), and dysplastic (precancer) and control (normal) groups using an in-house developed compact set-up. Fluorescence set-up consists of a 375-nm laser diode and optical components. Spectral bands of flavin adenine dinucleotide (FAD), porphyrins, and Raman are observed in the spectral range of 400 to 800 nm. Presence of FAD and porphyrin bands in human saliva is confirmed by the liquid phantoms of FAD and porphyrin. Significant differences in fluorescence intensities among all the three groups are observed. Three spectral ranges from 455 to 600, 605 to 770, and 400 to 800 nm are selected for each group and area values under each spectral range are computed. To differentiate among the groups, receiver operating characteristic (ROC) analysis is employed on the area values. ROC differentiates among the groups with accuracies of 98%, 92.85%, and 81.13% respectively in the spectral ranges of 400 to 800 nm. However, in other two spectral ranges (455 to 600 and 605 to 770 nm), low accuracy values are found. Obtained accuracy values indicate that selection of human saliva for head and neck cancer detection may be a good alternative.

Beyond liquid biopsy: Toward non-invasive assays for distanced cancer diagnostics in pandemics

Liquid biopsy technologies have seen a significant improvement in the last decade, offering the possibility of reliable analysis and diagnosis from several biological fluids. The use of these technologies can overcome the limits of standard clinical methods, related to invasiveness and poor patient compliance. Along with this there are now mature examples of lab-on-chips (LOC) which are available and could be an emerging and breakthrough technology for the present and near-future clinical demands that provide sample treatment, reagent addition and analysis in a sample-in/answer-out approach. The possibility of combining non-invasive liquid biopsy and LOC technologies could greatly assist in the current need for minimizing exposure and transmission risks. The recent and ongoing pandemic outbreak of SARS-CoV-2, indeed, has heavily influenced all aspects of life worldwide. Ordinary tasks have been forced to switch from “in presence” to “distanced”, limiting the possibilities for a large number of activities in all fields of life outside of the home. Unfortunately, one of the settings in which physical distancing has assumed noteworthy consequences is the screening, diagnosis and follow-up of diseases.

In this review, we analyse biological fluids that are easily collected without the intervention of specialized personnel and the possibility that they may be used -or not-for innovative diagnostic assays. We consider their advantages and limitations, mainly due to stability and storage and their integration into Point-of-Care diagnostics, demonstrating that technologies in some cases are mature enough to meet current clinical needs.

Genetic polymorphism of tumor necrosis factor alpha (TNF-α) and tumor necrosis factor beta (TNF-β) genes and risk of oral pre-cancer and cancer in North Indian population

OBJECTIVE

There are inconclusive data connecting single-nucleotide polymorphisms (SNPs) of TNF-α (rs361525) and TNF-β (rs909253) to potential malignant oral disorder (PMOD) such as lichen planus and oral fibrosis. Here, we have investigated the risk of oral squamous cell carcinoma as well as oral pre-cancerous lesions in North Indian population with the polymorphism of the TNFα/ β genes.

MATERIAL AND METHODS

A total 500 patients with oral pre-cancer and OSCC and 500 healthy volunteers were genotypes for the TNF-α (-238) G/A (rs361525) and TNF-β (252) A/G (rs909253) gene polymorphism. Genotypes were identified by polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP). Genotype frequencies were evaluated by Chi-square test.

RESULTS

Compared to the GG genotype, the GA genotype of TNF-α (G238A) polymorphism (rs361525) has been found to significantly increase the risk of oral disease (OR = 1.99) and especially the risk of lichen planus and OSCC (OR = 2.805 and 5.790, respectively). Similarly, the risk of oral disease was also more in the heterozygote (AG) than the common allele homozygote (AA) of TNF-β (A252G) polymorphism (rs909253) (OR = 1.483).

CONCLUSION

We conclude that the SNPs rs361525 and rs909253 were significantly associated with oral pre-cancer and OSCC.

Ultrasensitive biosensing platform based on yttria doped zirconia-reduced graphene oxide nanocomposite for detection of salivary oral cancer biomarker

Herein, we report results of the studies relating to the fabrication of yttria-doped zirconia-reduced graphene oxide nanocomposite (nYZR) based biosensing platform for detection of salivary CYFRA-21-1 biomarker. The nYZR nanocomposite was hydrothermally synthesized and amine-functionalized using 3-aminopropyl triethoxysilane (APTES). This functionalized nanocomposite (APTES/nYZR) was electrophoretically deposited (45 V; 3 min) onto pre-hydrolyzed indium tin oxide (ITO) coated glass substrate (APTES/nYZR/ITO) followed by biofunctionalization via covalent immobilization of the anti-CYFRA-21-1 antibodies (anti-CYFRA-21-1/APTES/nYZR/ITO). The synthesized nanomaterial and the fabricated electrodes were characterized to investigate crystal structure, morphology and electrochemical properties via X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. The fabricated biosensing electrode (BSA/anti-CYFRA-21-1/APTES/nYZR/ITO) has an operating shelf life of 56 days and can be used to detect salivary CYFRA-21-1 biomarker concentration as low as 7.2 pg mL^-1 with wide linear detection range of 0.01-50 ng mL^-1. This work opens new opportunities to explore the electrochemical behavior of nanostructured yttria stabilized zirconia (YSZ) and its composites at room temperature and its utility in developing biosensors and other electrochemical devices.

Recent advances in graphene-based nanobiosensors for salivary biomarker detection

As biosensing research is rapidly advancing due to significant developments in materials, chemistry, and electronics, researchers strive to build cutting-edge biomedical devices capable of detecting health-monitoring biomarkers with high sensitivity and specificity. Biosensors using nanomaterials are highly promising because of the wide detection range, fast response time, system miniaturization, and enhanced sensitivity. In the recent development of biosensors and electronics, graphene has rapidly gained popularity due to its superior electrical, biochemical, and mechanical properties. For biomarker detection, human saliva offers easy access with a large variety of analytes, making it a promising candidate for its use in point-of-care (POC) devices. Here, we report a comprehensive review that summarizes the most recent graphene-based nanobiosensors and oral bioelectronics for salivary biomarker detection. We discuss the details of structural designs of graphene electronics, use cases of salivary biomarkers, the performance of existing sensors, and applications in health monitoring. This review also describes current challenges in materials and systems and future directions of the graphene bioelectronics for clinical POC applications. Collectively, the main contribution of this paper is to deliver an extensive review of the graphene-enabled biosensors and oral electronics and their successful applications in human salivary biomarker detection.

Serum alkaline phosphatase in oral squamous cell carcinoma and its association with clinicopathological characteristics

Context:

Biochemical changes occur in biological fluids and tissues of different types of malignancies. Tumor markers in serum, tissue, and other body fluids during neoplastic process are of clinical value in the management of patients with cancers. Serum alkaline phosphatase (ALP) activity is potentially a useful indicator for detection of malignancies, but its status in oral squamous cell carcinoma (OSCC) is less explored.

Aims:

The aim of this study is to evaluate the serum level of ALP in OSCC patients and assess its relation with the clinicopathological features.

Settings and Design:

A total of 175 participants (145 OSCC patients and 30 healthy controls) were included in the study. One hundred and forty-five patients with OSCC who underwent treatment at our institution were included to obtain the clinicopathological data.

Materials and Methods:

Fasting blood ALP activity was evaluated using ALP assessment kit and biochemistry analyzer.

Statistical Analysis Used:

The data were analyzed by SPSS-21 software (SPSS Statistics for Windows, Version 21.0, Armonk, NY, USA), using t-test, Mann–Whitney U, and Kruskal–Wallis tests.

Results:

Raised ALP was seen in 24% of OSCC patients. The mean ALP in OSCC was significantly higher than the control. ALP level in patients with advanced stage was significantly higher than with early stage. The serum ALP level in OSCC patients with bone involvement (BI) by local extension of tumor was significantly higher than without BI.

Conclusion:

ALP showed statistically significant differences in relation to tumor stages and BI. Hence, ALP could be useful in advanced stage disease for expressing the endurance of patient and tumor expansion. Elevated ALP in OSCC patients may indicate BI.

Microneedles and Nanopatches-Based Delivery Devices in Dentistry

Needle-based devices are evolving as a promising diagnostic and therapeutic tool in the field of medicine. They can be used for drug delivery, as well as extraction of fluids, for systemic and local effects. The conventional methods of drug delivery require repeated dosing in the oral cavity due to the presence of saliva. Hence delivery systems, such as needle-based devices that could provide sustained release of the drug in the oral cavity, are required. These devices could also be a useful adjunct in diagnosis and therapy of oral cancers, delivering anti-cariogenic and antiplaque agents, for remote monitoring of oral health, and for administering painless and fearless local anesthesia. Since they offer many advantages, such as increased compliance, absence of needle phobia, they are painless, safe, self-applicable and are minimally invasive, they will have a major impact in the field of dentistry. This paper summarizes the various types of needle-based devices and their manufacturing technologies. The manuscript aims to serve as a foundational review that highlights and proposes several current and prospective impactful applications of these devices in various fields of dentistry.

Application of salivary noncoding microRNAs for the diagnosis of oral cancers

Oral cancer is on the rise globally and survival rates, despite improvements in clinical care, have not significantly improved. Early detection followed by immediate intervention is key to improving patient outcomes. The use of biomarkers has changed the diagnostic landscape for many cancers. For oral cancers, visual inspection followed by a tissue biopsy is standard practice. The discovery of microRNAs as potential biomarkers has attracted clinical interest but several challenges remain. These microRNAs can be found in bodily fluids such as blood and saliva which have been investigated as potential sources of biomarker discovery. As oral cancer is localized within the oral cavity, saliva may contain clinically relevant molecular markers for disease detection. Our review provides an outline of the current advances for the application of salivary microRNAs in oral cancer. We also provide a technical guide for the processing of salivary RNAs to ensure accurate clinical measurement and validation.

[Diagnostic accuracy of salivary biomarkers for oral cancer and potentially malignant disorders: A systematic review protocol]

INTRODUCTION

Oral cancer has a 5-year survival rate of 50% because diagnosis is commonly performed at an advanced stage of the disease, so new diagnostic tools are needed. Nowadays, there is a vast number of publications suggesting the use of salivary biomarkers for oral cancer and potentially malignant disorders diagnosis, but their diagnostic accuracy is unclear. Thus, the goal of this systematic review is to evaluate the diagnostic accuracy of salivary biomarkers for oral cancer and potentially malignant disorders.

METHODS

This protocol is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P). We will include primary studies assessing the diagnostic accuracy of salivary biomarkers for oral cancer and potentially malignant disorders. Studies must report data about sensitivity and specificity; gold standard must be the histopathology diagnosis. We will search MEDLINE, EMBASE, the Cochrane Library, and gray literature. Two authors will independently select the studies and extract the data. The methodology quality of studies will be determined using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2).

EXPECTED RESULTS AND CONCLUSION

Our findings will provide information about the diagnostic accuracy of salivary biomarkers for oral cancer and potentially malignant disorders.

Salivary biomarkers in breast cancer: a cross-sectional study

AIM

The objective was to evaluate the diagnostic value of salivary biomarkers in breast cancer.

MATERIALS AND METHODS

A prospective study was carried out of 91 consecutive breast cancer patients and 60 controls without neoplastic disease. Demographic data were recorded, along with the Hospital Anxiety Depression (HAD), risk for development periodontal diseases questionnaire and Mini-Nutritional Assessment (MNA) scores, and the TNM classification and stage of the primary tumor. Unstimulated basal saliva samples were collected and stored at - 80 °C until analysis.

RESULTS

The mean salivary CA125 concentration was 102.1 pg/ml in the control group and 267.6 pg/ml in the breast cancer group (p = 0.005). The soluble Fas (sFas) concentration in turn was 84.1 pg/ml and 145.9 pg/ml, respectively (p = 0.008). None of the biomarkers was related to questionnaire-assessed risk for development of periodontal diseases. The area under the ROC curve was 0.68 for CA125 (95% CI, 0.05-0.56) and 0.67 for sFas (95% CI, 0.08-0.55).

CONCLUSIONS

The salivary biomarkers CA125 and sFas appear to be promising tools in the diagnosis of breast cancer.

A Review of Salivary Diagnostics and Its Potential Implication in Detection of Covid-19

Saliva is an exocrine secretion produced from the salivary glands and has numerous functions, such as cleansing and protection of the oral cavity, antimicrobial effects and aids in digestion. Due to the speedy development in the field of salivaomics, saliva is now well accepted as a pool of biological markers that vary from changes in biochemicals, nucleic acids and proteins to the microflora. Saliva has an immense potential as a diagnostic fluid and offers an edge over other biological fluids as its collection method does not require invasive procedure, economical and is useful for monitoring systemic health. Development of sensitive and precise salivary diagnostic tools and the formulation of defined guidelines following meticulous testing will allow salivary diagnostics to be utilised as chair side tests for various oral and systemic diseases in the near future. The coronavirus disease (Covid-19) pandemic is the biggest challenge and global health crisis for the world since World War Two. Rapid and accurate diagnosis of Covid-19 is crucial in controlling the outbreak in the community and in hospitals. Nasopharyngeal and oropharyngeal swabs are the recommended specimen types for Covid-19 diagnostic testing. The collection of these specimen types requires close contact between healthcare workers and patients and poses a risk of transmission of the virus, causes discomfort and may cause bleeding, especially in patients with condition such as thrombocytopenia. Hence, nasopharyngeal or oropharyngeal swabs are not desirable for sequential monitoring of viral load. Saliva specimens can be obtained easily as the patient is asked to spit into a sterile bottle. The collection of saliva is non-invasive and greatly minimizes the exposure of healthcare workers to Covid-19. Saliva has a high consistency rate of greater than 90% with nasopharyngeal specimens in the detection of respiratory viruses, including coronaviruses. Saliva has also been used in screening respiratory viruses among hospitalized patients without pyrexia or respiratory symptoms. SARS-CoV can be detected in saliva at high titers. Salivary diagnostics is a dynamic field that is being incorporated as part of disease diagnosis, clinical monitoring of systemic health and to make significant clinical decisions for patient care. More research is required to analyze the potential diagnostic of Covid-19 in saliva to develop rapid chair side tests for the detection of Covid-19 and it is also pivotal to improve and develop successful strategies for prevention, especially for dentists and healthcare professionals who are involved in performing aerosol-generating procedures.

Oral squamous cell carcinoma: metastasis, potentially associated malignant disorders, etiology and recent advancements in diagnosis

Oral squamous cell carcinoma (OSCC) is a commonly occurring head and neck cancer. It has a high prevalence in certain parts of the world, and is associated with a high mortality rate. In this review, we describe metastasis related to OSCC, and disorders that could lead to OSCC with common etiological factors. In addition, a brief account of the diagnosis of OSCC and role of salivary biomarkers in its early detection has also been highlighted. Google Scholar and PubMed search engines were searched with keywords including “oral squamous cell carcinoma”, “OSCC”, “oral cancer”, “potentially malignant disorders in oral cavity”, “etiological factors of OSCC”,  “diagnosis of OSCC”, and “salivary biomarkers and OSCC” to gather the literature for this review. The review concludes that OSCC has the potential for regional as well as distant metastasis, and many potentially malignant diseases can transform into OSCC with the help of various etiological factors. Diagnosis of OSCC involves traditional biopsy, but salivary biomarkers could also be utilized for early recognition.

Ratio of Salivary Sialic Acid to Fucose as Tumor Markers in Potentially Malignant Disorders and Oral Cancer

BACKGROUND

Lack of noninvasive and economically feasible laboratory investigations in the early detection of cancer is a set-back in the prognosis of oral cancer (OC) patients.

AIMS

The aim of the study was to evaluate the ratio of sialic acid to fucose in salivary samples of OC and oral potentially malignant disorder (OPMD) patients.

MATERIALS AND METHODS

A total of 60 participants were selected and divided into three groups based on clinical and histopathological diagnosis: OC patients (n = 20), OPMD patients (n = 20), and healthy patients (n = 20). Unstimulated whole saliva of 1.5 ml was collected from the selected individuals for evaluating the salivary levels of sialic acid and fucose using the biochemical assay.

RESULTS

The difference in mean salivary sialic acid and fucose among the study groups was statistically significant (P = 0.001); one-way analysis of variance. The mean sialic acid to fucose ratio in the control group, OPMD group, and OC group were 0.34 mg/dl, 0.88 mg/dl, and 0.89 mg/dl, respectively. OC patients had significant elevation in the levels of salivary sialic acid, fucose, and their ratios (P = 0.001, P = 0.001, P = 0.003, respectively); Tukey's post hoc test.

CONCLUSIONS

The ratio of salivary sialic acid to fucose is a predictable tumor marker for the diagnosis of OC. Further investigations are required to evaluate the influence of OC grading on this diagnostic marker.

Saliva as a diagnostic tool for dental caries, periodontal disease and cancer: is there a need for more biomarkers?

Introduction: A biomarker is a biological indicator of normal or pathogenic processes. Identification of biomarkers is useful for the prevention, diagnosis and prognosis of diseases as well as for monitoring the progression of pathological disorders. Several types of molecules present in biological fluids can act as biomarkers such as DNA, coding and non-coding RNA, lipids, metabolites, proteins and even microbes. In this context, saliva emerges as a useful diagnostic tool for the detection of biomarkers involved with oral and systemic diseases, since it reflects the pathophysiological conditions of the organism and allows early, rapid, practical and noninvasive detection of biomarkers.Areas covered: This review discusses the properties of saliva as a diagnostic tool and addresses the main identified biomarkers related to dental caries, periodontal disease, head and neck cancer and other types of cancer of considerable incidence among the world population.Expert commentary: Despite extensive efforts which have been directed toward the identification of one or a combination of biomarkers with good predictive values for the early detection of dental caries, periodontal disease and cancer, these biomarkers still need validation before chairside point-of-care devices can be widely used in the clinic.

Salivary exosomal miR-24-3p serves as a potential detective biomarker for oral squamous cell carcinoma screening

OBJECTIVES

miRNAs in salivary exosomes are used as novel non-invasive biomarkers for detection strategies of human disease. Here, we aimed to investigate the diagnostic potential of salivary exosomal miRNAs as biomarkers for screening oral squamous cell carcinoma (OSCC) and to explore the underlying mechanisms of OSCC pathogenesis.

MATERIALS AND METHODS

Differentially expressed miRNAs were obtained from salivary exosomes of four healthy controls and four OSCC patients using miRNA microarray analysis. The expression of miR-24-3p in the salivary exosomes was then verified by qRT-PCR. The diagnostic power was assessed by receiver operating characteristic (ROC) analysis. Cell proliferation was measured using CCK-8 cell viability assay and colony formation assay. The target gene of miR-24-3p was confirmed by dual luciferase reporter assay.

RESULTS

A total of 109 miRNAs were found to be more than 2-fold altered in the salivary of patients and healthy individuals by miRNA microarray. qRT-PCR analysis further confirmed a significant increase of miR-24-3p in the salivary exosomes from 45 preoperative OSCC patients compared to 10 normal controls. ROC analysis showed that miR-24-3p has excellent diagnostic accuracy for OSCC (area under the ROC curve [AUC] = 0.738; P =  0.02). Similarly, we found that miR-24-3p expressed a higher level in OSCC neoplastic tissues, suggesting that circulating miR-24-3p may originate from tumor cells. Furthermore, exogenous exosomal miR-24-3p increased proliferation of recipient malignant cells. Additionally, overexpression of miR-24-3p promoted the proliferation of OSCC cells and regulated the expression of cell cycle-related genes. Dual luciferase reporter assay indicated that miR-24-3p can interact with PER1 directly.

CONCLUSIONS

Salivary exosomal miR-24-3p is a potential novel diagnostic biomarker for OSCC, and miR-24-3p can maintain the proliferation of OSCC cells through targeting PER1.

A New Approach for the Diagnosis of Systemic and Oral Diseases Based on Salivary Biomolecules

Early diagnosis represents the target of contemporary medicine and has an important role in the prognosis and further treatment. Saliva is a biofluid that generated a high interest among researchers due to its multiple advantages over other body fluids. The multitude of components that can act as biomarkers influenced the existing technologies to develop protocols that could allow saliva to become the new noninvasive diagnostic method. Saliva as a diagnostic tool can bring substantial addition to the diagnostic armamentarium, providing important information about oral and general health. The diagnostic applications of saliva extended and had a rapid evolution due to the advancement in salivaomics. The present review summarizes the latest researches in saliva-related studies and explores the information and correlations that saliva can offer regarding the systemic and oral diseases, highlighting its great potential of diagnosis. It is expected that in the future specific guidelines and results regarding the salivary diagnostics are to be available, together with high-sensitivity and specificity tests for multiple systemic and oral diseases.

A review of the most promising biomarkers for early diagnosis and prognosis prediction of tongue squamous cell carcinoma

BACKGROUND

There is a great interest in developing biomarkers to enhance early detection and clinical management of tongue squamous cell carcinoma (TSCC). However, the developmental path towards a clinically valid biomarker remains extremely challenging. Ideally, the initial key step in moving a newly discovered biomarker towards clinical implementation is independent replication. Therefore, the focus of this review is on biomarkers that consistently showed clinical relevance in two or more publications.

METHODS

We searched PubMed database for relevant papers across different TSCC sample sources, i.e., body fluids (saliva, serum/plasma) and tissues. No restriction regarding the date of publication was applied except for immunohistochemistry (IHC); only studies published between 2010 and June 2017 were included.

RESULTS

The search strategy identified 1429 abstracts, of which 96 papers, examining 150 biomarkers, were eventually included. Of these papers, 66% were exploratory studies evaluating single or a panel of biomarkers in one publication. Ultimately, based on studies that had undergone validation for their clinical relevance in at least two independent studies, we identified 10 promising candidates, consisting of different types of molecules (IL-6, IL-8, and Prolactin in liquid samples; HIF-1α, SOX2, E-cadherin, vimentin, MALAT1, TP53, and NOTCH1 in tissue biopsies) CONCLUSIONS: Although more exploratory research is needed with newer methods to identify biomarkers for TSCC, rigorous validation of biomarkers that have already shown unbiased assessment in at least two publications should be considered a high priority. Further research on these promising biomarkers or their combination in multi-institutional studies, could provide new possibilities to develop a specific panel for early diagnosis, prognosis, and individualized treatments.

Role of Salivary Biomarkers in Oral Cancer Detection

Oral cancers are the sixth most frequent cancer with a high mortality rate. Oral squamous cell carcinoma accounts for more than 90% of all oral cancers. Standard methods used to detect oral cancers remain comprehensive clinical examination, expensive biochemical investigations, and invasive biopsy. The identification of biomarkers from biological fluids (blood, urine, saliva) has the potential of early diagnosis. The use of saliva for early cancer detection in the search for new clinical markers is a promising approach because of its noninvasive sampling and easy collection methods. Human whole-mouth saliva contains proteins, peptides, electrolytes, organic, and inorganic salts secreted by salivary glands and complimentary contributions from gingival crevicular fluids and mucosal transudates. This diagnostic modality in the field of molecular biology has led to the discovery and potential of salivary biomarkers for the detection of oral cancers. Biomarkers are the molecular signatures and indicators of normal biological, pathological process, and pharmacological response to treatment hence may provide useful information for detection, diagnosis, and prognosis of the disease. Saliva's direct contact with oral cancer lesions makes it more specific and potentially sensitive screening tool, whereas more than 100 salivary biomarkers (DNA, RNA, mRNA, protein markers) have already been identified, including cytokines (IL-8, IL-1b, TNF-α), defensin-1, P53, Cyfra 21-1, tissue polypeptide-specific antigen, dual specificity phosphatase, spermidine/spermineN1-acetyltransferase , profilin, cofilin-1, transferrin, and many more. However, further research is still required for the reliability and validation of salivary biomarkers for clinical applications. This chapter provides the latest up-to-date list of known and emerging potential salivary biomarkers for early diagnosis of oral premalignant and cancerous lesions and monitoring of disease activity.

Saliva CA125 and TPS Levels in Patients with Oral Squamous Cell Carcinoma

Objectives

To determine the levels of carbohydrate antigen 125 (CA125) and tissue polypeptide-specific antigen (TPS) in saliva of patients with oral squamous cell carcinoma (OSCC) and patients with nonneoplastic disease of the oral cavity, and to investigate their diagnostic value and their relationship with pathological grade and clinical stage.

Methods

A total of 97 hospitalized patients with OSCC, 36 patients with nonneoplastic disease of the oral cavity and 50 healthy individuals were included in this investigation. Mixed saliva was collected from these patients and the healthy controls before treatment. Saliva samples were analyzed by enzyme-linked immunosorbent assay (ELISA).

Results

The saliva CA125 and TPS concentrations were significantly higher in patients with OSCC than in patients with nonneoplastic disease and healthy controls, but not significantly different between patients with nonneoplastic disease and controls. Neither the saliva CA125 nor the TPS level was correlated with pathological grade and clinical stage. The sensitivity, specificity and accuracy of saliva CA125 and TPS for the diagnosis of OSCC were 80.0%, 66.0%, 75.7%, and 82.1%, 74.0%, 79.3%, respectively. When CA125 and TPS were analyzed independently, there was no significant difference in sensitivity, specificity and accuracy between the two markers. When CA125 and TPS were analyzed in combination, there was no significant difference in sensitivity, specificity and accuracy between independent detection and combined detection.

Conclusions

The saliva CA125 and TPS concentrations were elevated in patients with OSCC. CA125 and TPS may prove to be useful tumor markers in OSCC.

Salivary proteome profiling of oral squamous cell carcinoma in a Hungarian population

Oral squamous cell carcinoma (OSCC) is the seventh most common malignancy and the ninth most frequent cause of cancer death in Europe. Within Europe, Hungary has one of the highest rates of OSCC incidence and mortality. Thus, there is an urgent need to improve early detection. Saliva, as a readily available body fluid, became an increasingly important substance for the detection of biomarkers for many diseases. Different research groups have identified salivary biomarkers specific for OSCC for different countries. In this study, saliva samples of Hungarian patients with OSCC were studied to discover disease‐specific and perhaps region‐specific biomarkers. LC‐mass spectrometry (MS)/MS analysis on a linear ion trap‐Orbitrap mass spectrometer was used for qualitative and quantitative salivary protein profiling. More than 500 proteins were identified from saliva by shotgun proteomics. The up‐ and downregulated proteins in the saliva of patients with OSCC highlighted the importance of protein–protein interaction networks involving the immune system and proteolysis in disease development. Two potential biomarkers from our shotgun analysis and a third candidate reported earlier by a Taiwanese group were further examined by ELISA on a larger reference set of samples. Resistin, a biomarker reported in Taiwan but not validated in our study, highlights the necessity of application of standardized analysis methods in different ethnic or geographical populations to identify biomarkers with sufficient specificity and sensitivity.

Human Saliva for Oral Precancer Detection: a Comparison of Fluorescence & Stokes Shift Spectroscopy

We report here a study on human saliva tested as a diagnostic medium for oral cancer detection on three groups: oral squamous cell carcinoma (OSCC), oral sub mucous fibrosis (OSMF; precancer), and healthy controls (normal). Measurements have been conducted using fluorescence spectroscopy with 350 nm excitation and Stokes shift (SS) spectroscopy (SSS) with 120 nm shift from a total of 99 saliva samples. For classification, principal component analysis (PCA) and linear discriminant analysis (LDA) have been applied on the data sets. Linear discriminant (LD) scores of fluorescence spectra are able to differentiate OSCC to normal, OSMF to normal and OSCC to OSMF with sensitivities 91%, 92%, 91% and specificities 97%, 100%, 94% respectively, while LD scores of SS spectra differentiate respective groups with sensitivities 100%, 94%, 94% and specificities 97%, 100%, 94%. Cross-validation on the datasets of PC scores during LDA illustrates that sensitivity and specificity of SSS data are less affected than those of fluorescence data. Saliva is thus seen as a potential non-invasive and simple diagnostic medium, with SS spectroscopy as a better diagnostic tool for oral precancer.

"Omics" in oral cancer: New approaches for biomarker discovery

OBJECTIVES

In this review paper, we explored the application of "omics" approaches in the study of oral cancer (OC). It will provide a better understanding of how "omics" approaches may lead to novel biomarker molecules or molecular signatures with potential value in clinical practice. A future direction of "omics"-driven research in OC is also discussed.

METHODS

Studies on "omics"-based approaches [genomics/proteomics/transcriptomics/metabolomics] were investigated for differentiating oral squamous cell carcinoma,oral sub-mucous fibrosis, oral leukoplakia, oral lichen planus, oral erythroplakia from normal cases. Electronic databases viz., PubMed, Springer, and Google Scholar were searched.

RESULTS

One eighty-one studies were included in this review. The review shows that the fields of genomics, transcriptomics, proteomics, and metabolomics-based marker identification have implemented advanced tools to screen early changes in DNA, RNA, protein, and metabolite expression in OC population.

CONCLUSIONS

It may be concluded that despite advances in OC therapy, symptomatic presentation occurs at an advanced stage, where various curative treatment options become very limited. A molecular level study is essential for detecting an OC biomarker at an early stage. Modern "Omics" strategies can potentially make a major contribution to meet this need.

Proteomics investigation of OSCC-specific salivary biomarkers in a Hungarian population highlights the importance of identification of population-tailored biomarkers

Oral squamous cell carcinoma (OSCC) accounting for about 90% of malignant oral lesions is the 6th most common malignancy worldwide. Diagnostic delay may contribute to dismal survival rate therefore, there is a need for developing specific and sensitive biomarkers to improve early detection. Hungarian population occupies the top places of statistics regarding OSCC incidence and mortality figures therefore, we aimed at finding potential salivary protein biomarkers suitable for the Hungarian population. In this study we investigated 14 proteins which were previously reported as significantly elevated in saliva of patients with OSCC. In case of IL-1α, IL-1β, IL-6, IL-8, TNF-α and VEGF a Luminex-based multiplex kit was utilized and the salivary concentrations were determined. In case of catalase, profilin-1, S100A9, CD59, galectin-3-bindig protein, CD44, thioredoxin and keratin-19, SRM-based targeted proteomic method was developed and the relative amount of the proteins was determined in the saliva of patients with OSCC and controls. After several rounds of optimization and using stable isotope-containing peptides, we developed an SRM-based method for rapid salivary protein detection. The validation of the selected potential biomarkers by ELISA revealed salivary protein S100A9 and IL-6 as useful protein biomarkers for OSCC detection improving the diagnostic accuracy for OSCC in the Hungarian population.A noninvasive diagnostic method to detect biomarkers useful for the early diagnosis of OSCC was developed. This can be an attractive strategy in screening saliva samples collected in a nation-wide multi-centric study in order to decrease morbidity, mortality, to enhance survival rate and to improve quality of life. The heterogeneity of protein biomarkers found in different ethnic groups presented in the literature highlights the importance of identification of population-tailored protein biomarkers.