Oral Epithelial Dysplasia May Progress to Squamous Cell Carcinoma:

Prognostic biomarkers for malignant progression of oral epithelial dysplasia: an updated systematic review and meta-analysis

Oral epithelial dysplasia (OED) is a premalignant condition that carries an appreciable risk of malignant progression. The current grading system for severity, as defined by the World Health Organization, is a valuable clinical tool, but further work is required to improve the accuracy of predicting OED malignant progression. This systematic review aimed to assess progress in prognostic biomarker discovery in OED over the past 16 years. The primary objective was to update the latest evidence on prognostic biomarkers that may predict malignant progression of OED, with strict inclusion criteria of studies with a longitudinal design and long-term follow-up data to enhance the robustness and translational clinical potential of the findings. Of 2829 studies identified through the searching of five databases, 20 met our inclusion criteria. These studies investigated a total of 32 biomarkers, 20 of which demonstrated significant potential to predict malignant progression of OED. Meta-analysis demonstrated the significant prognostic value of four biomarkers: podoplanin, EGFR expression, p16 methylation, and DNA aneuploidy. Our review has identified 20 reported biomarkers with prognostic potential to predict malignant progression in OED, but their translation into clinical practice remains elusive. Further research is required, and this should focus on validating the promising biomarkers identified in large cohort studies, with adherence to standardised reporting guidelines.

Exome sequencing of oral leukoplakia and oral squamous cell carcinoma implicates DNA damage repair gene defects in malignant transformation

OBJECTIVES

To map the genomic pathways of patients with oral leukoplakia (OLK) which transformed to cancer (progressive) and those which did not (non-progressive), and to compare their exomic profiles.

MATERIALS AND METHODS

Whole exome sequencing was performed on 42 sequential samples from five progressive and eight non-progressive patients. Association of genomic variant frequencies with progression or lesion severity were analysed by non-parametric tests (Kruskal-Wallis and Mann-Whitney-Wilcoxon) and multivariate sparse partial least squares discriminant analysis (sPLS-DA). Enrichment analysis was used to characterise the effect of mutations upon biological pathways. Confirmatory studies used qPCR and immunohistochemistry.

RESULTS

Using sPLS-DA, the variant frequency of a small number of genes could be used to classify the samples based on lesion severity or progressive status. Enrichment analysis showed that DNA damage repair gene related pathways were highly impacted in lesions which progressed to cancer. Multivariate analysis of a set of 148 DNA damage repair genes could be used to classify progressive lesions using mutation frequency. BRCA1, BRCA2 and other double strand break (DSB) repair Fanconi anaemia (FA)/BRCA pathway genes were prominent contributors to this classification.

CONCLUSION

Patients with progressive and non-progressive OLK can be differentiated using the frequency of exomic variants, particularly in DNA damage repair pathway genes. To our knowledge, this is the first report of FA/BRCA (DSB) pathway involvement in malignant transformation of OLK to oral squamous cell carcinoma (OSCC).

Mucosal disorders with oral epithelial dysplasia risk--development of a simple screening tool for general health care setting

OBJECTIVES

Oral visual screening can avert oral cancer mortality. Oral premalignancies are currently considered as separate, individual disorders. The objective was to develop a simple clinical screening tool to detect oral premalignancies in general health care setting and validate diagnostic accuracy against Oral Medicine specialist examination as gold standard.

MATERIALS AND METHODS

All steps in development of new tool, from item generation to item selection and item reduction were carried out. Item generation was done using qualitative methods. After pre-testing and piloting, junior dental house surgeon administered the refined tool, to patients attending dental outpatient department (n=255). Subsequent evaluation by an Oral Medicine specialist using consensus clinical criteria, detected 59 screen positive cases. Each case was recoded as per scores assigned by binary logistic regression coefficients and total score computed. The Receiver Operator Characteristic (ROC) was performed against specialist examination as gold standard. Performance ability and reliability coefficient of final tool was assessed. A simple score was assigned to indicate stage and clinical severity.

RESULTS

Screening Tool for Oral Premalignancies (STOP) has sensitivity 96.6%, specificity 99.0% and accuracy 98.4% with reliability coefficient 0.874. Scores detect clinical signs and staging reflect clinical severity alerts.

CONCLUSION

Oral Potentially Malignant Disorders need to be evaluated as single entity, under a common umbrella - Mucosal Disorders with Oral Epithelial Dysplasia risk (MD-OEDr). STOP is a simple tool for opportunistic general health care screening of MD-OEDr.