Is salivary epidermal growth factor a biomarker for oral leukoplakia? A preliminary study

Salivary EGF: EGFR ratio as potential early diagnostic biomarker for oral cancer detection in tobacco chewers: a preliminary cross-sectional study

BACKGROUND

Tobacco chewing and smoking are major risk factors for oral cancer, with Oral Squamous Cell Carcinoma (OSCC), comprising approximately 90% of cases, especially in South-Central Asia. This study examines the early diagnostic value of salivary Epidermal Growth Factor (EGF) and Epidermal Growth Factor Receptor (EGFR) for OSCC in long-term chewers of tobacco.

METHODS

This study assessed salivary EGF and EGFR concentrations by Enzyme-Linked Immunosorbent Assay (ELISA), in three groups: Healthy Controls (HC, n = 41), Tobacco Chewers with a 10-years history of tobacco use (TC, n = 41), and newly diagnosed OSCC patients (with tobacco chewing history of more than 10 years) with no prior history of neoplasms or anticancer treatment (OSCC, n = 19). All participants were over the age of 35.

RESULTS

Salivary EGF levels were significantly reduced, while EGFR levels were elevated in tobacco chewers (TC) and newly diagnosed OSCC patients compared to healthy controls (HC), with no significant difference observed between TC and OSCC groups. Notably, the EGF: EGFR ratio demonstrated better diagnostic performance for OSCC in TC compared to EGF or EGFR alone. ROC analysis highlighted the potential of these biomarkers as diagnostic tools for OSCC in TC.

CONCLUSION

Salivary EGF: EGFR ratio may serve as an early diagnostic biomarker for OSCC in TC. Reduced EGF and elevated EGFR levels suggest their role in disease progression, warranting further large-scale studies for clinical validation.

Expression of epithelial growth factor receptor as a protein marker in oral reticular and erosive lichen planus

BACKGROUND

Oral lichen planus (OLP) is a chronic inflammatory mucosal disease that is classified as a premalignant condition. Epithelial growth factor receptor (EGFR) is associated with tumorigenesis and tumor progression and is overexpressed in several oral malignant disorders. Despite the association of EGFR overexpression with oral potentially malignant lesions, few studies have analyzed its expression in OLP, showing controversial results. This study aimed to compare the expression of EGFR as a protein marker in Reticular and Erosive OLP.

METHODS

This descriptive-analytical cross-sectional was conducted on 15 paraffin blocks of reticular lichen planus lesions, 16 paraffin blocks of erosive OLP lesions, and 8 paraffin blocks of inflammatory fibrous hyperplasia lesions as the control group (39 in total). After immunohistochemical staining for EGFR, samples were simultaneously observed by two maxillofacial pathologist, and the percentage of stained cells, intensity of staining, pattern of staining, and the location of stained cells were obtained.

RESULTS

The Mann-Whitney-U test showed that there was no significant difference in the mean percentage of stained cells between erosive OLP and reticular OLP (P-value = 0.213) and between reticular OLP and control group (P-value = 0.137), but there was a significant difference between erosive OLP and control group (P-value = 0.035). Fisher's exact test showed that there was no significant difference between the frequency distribution of staining patterns in three types of lesions (P-value = 0.90). Kruskal-Wallis test showed that there was no significant difference between the intensity of staining in the three groups (P-value = 0.19) and also there was no significant difference between the location of stained cells in different layers of the epithelium in the three groups (P-value = 0.90).

CONCLUSIONS

The results of this study showed that in comparison of reticular OLP, erosive OLP, and the control group there was a significant difference just between erosive OLP and control group in the percentage of stained cells.

Identification of EGFR as a Biomarker in Saliva and Buccal Cells from Oral Submucous Fibrosis Patients—A Baseline Study

Oral Submucous Fibrosis (OSMF) is a chronic debilitating disease more frequently encountered in the South-East Asian population. This disease represents a public health priority as it is grouped within oral potentially malignant disorders, with malignant transformation rates of around 7–19%. Hence, early identification of high-risk OSMF patients is of the utmost importance to prevent malignant transformation. Among various biomarkers, EGFR overexpression has an unfavorable clinical outcome, poor prognosis, and low survival rates in Oral Squamous Cell Carcinoma (OSCC). The current study aimed to evaluate the expression of EGFR in saliva and exfoliated buccal cells of OSMF. Immunoexpression of EGFR was observed in healthy controls (n = 11), OSCC (n = 106), and OPMD with dysplasia (n = 56), which showed significant expression with increasing grades of dysplasia and OSCC. EGFR expression was evaluated in saliva and exfoliated buccal cells of healthy controls (n = 15), OSMF (n = 24), and OSCC (n = 10) patients using ELISA, which revealed significant expression in OSMF and OSCC. Validation studies were also performed using real-time PCR (RT-PCR) to compare gene expression in healthy controls (n = 9), OSMF (n = 9), and OSCC (n = 25), which showed significant 18-fold upregulation in OSCC and three-fold upregulation in OSMF when compared to healthy controls. Hence, saliva and exfoliated buccal cells could be considered as potential non-invasive diagnostic samples for the evaluation of high-risk patients of OSMF using EGFR as a biomarker.

Recognizing the salivary panomics for the clinical application in oral potentially malignant disorders

Oral cancer arises as a result of multistep carcinogenic progress from precursor lesion to oral squamous cell carcinoma through collective mutational process occur in the stem cells of mucosal epithelium. The detection of such oral potentially malignant disorders (OPMDs)/cancer in subclinical level will greatly improve the prognosis of a patient. The highly specific and sensitive salivary biomarkers have functioned in detection, prediction, surveillance and therapeutic monitoring of the diseases of interest. The aim of the review is to appraise various salivary biomarkers for the clinical utility in OPMDs. An electronic web-supported search was performed via PubMed, ScienceDirect and Google Scholar search engine since the year 2015–2019. A total of 28 research articles were selected for the review after screening and assessment. The various genomic, transcriptomic, proteomic, metabolomic and miscellaneous markers were analyzed and their characteristics and clinical application in OPMD patients were discussed. miR-21, miR-31, miR-84, H3F3A mRNA + IL-8P, matrix metalloproteinase-9, chemerin, tumor necrosis factor-alpha, cytokeratin-10, ornithine + O-hydroxybenzoate + R5F, 8-hydroxy-2-deoxyguanosine, malondialdehyde, Vitamin E and Vitamin C are identified as potential markers for OPMD patients. Scientifically validated, reliable and economical clinical biomarkers in OPMDs would serve as evidence-based treatment from patient point of view. Further longitudinal studies are needed to verify the accuracy and validate the applicability of these diagnostic/prognostic markers. Saliva has been reported as a valuable noninvasive valuable tool in biomarker identification. Recent advancements in salivary biomarker identification techniques lead to various potential biomarkers with precise outcome. The utilization of these biomarkers for the clinical application in OPMDs depends on the feasibility and personal choice of the clinician.

Salivary Biomarkers and Their Application in the Diagnosis and Monitoring of the Most Common Oral Pathologies

Saliva is a highly versatile biological fluid that is easy to gather in a non-invasive manner—and the results of its analysis complement clinical and histopathological findings in the diagnosis of multiple diseases. The objective of this review was to offer an update on the contribution of salivary biomarkers to the diagnosis and prognosis of diseases of the oral cavity, including oral lichen planus, periodontitis, Sjögren’s syndrome, oral leukoplakia, peri-implantitis, and medication-related osteonecrosis of the jaw. Salivary biomarkers such as interleukins, growth factors, enzymes, and other biomolecules have proven useful in the diagnosis and follow-up of these diseases, facilitating the early evaluation of malignization risk and the monitoring of disease progression and response to treatment. However, further studies are required to identify new biomarkers and verify their reported role in the diagnosis and/or prognosis of oral diseases.

Oral cancer: Deregulated molecular events and their use as biomarkers

Oral Cancer (OC) is a subset of head and neck cancer (HNC) with an annual worldwide incidence of 275,000 cases. OC remains a significant burden worldwide in terms of diagnosis, treatment and prognosis. Despite desirable outcomes in early diagnosed OCs and treatment advances most OCs are detected in advanced stages. The 5-year survival rate of early-stage disease is ∼80% and that of late-stage disease is only ∼20%. Recurrence and chemoresistance from a treatment point of view and pain and disfiguration are important factors contributing to the high morbidity and mortality of OC. Furthermore the process of oral carcinogenesis is complex and not yet fully understood. Consequently numerous potential biomarkers have been hypothesised though controversial results across the board hamper their clinical implementation. Of greatest advantage would be biomarkers signalling early events preceeding OC. Biomarker targets predominately involve deregulated molecular events that participate in cell signalling, growth, survival, motility, angiogenesis and cell cycle control but can also use changes in metabolic genes to discriminate healthy form disease state. Promising potential biomarkers include the growth signalling oncogenes, Epidermal Growth Factor Receptor and Cyclin D1, the anti-growth signalling components p53 and p21, apoptotic effectors such as Bcl-2 and also components involved in immortalisation, angiogenesis, invasion and metastasis processes. Translation of these potential biomakers to the patients is closer than ever though few issues remain to be resolved. Firstly large clinical trials are needed to validate their clinical applicability but also standardised methods of collection, storage and processing methods are needed to minimise variability.