To treat...or not to treat? Clinicians' views on the management of oral potentially malignant disorders

Proliferative verrucous leukoplakia: a case report of multiple metachronous oral verrucous carcinoma

Proliferative verrucous leukoplakia (PVL) is a distinct progressive and multi-focal form of oral leukoplakia, not associated with the traditional risk factors (ie, tobacco and alcohol consumption). The incidence of oral squamous cell carcinoma in PVL patients is high. Here, we describe the case of a patient affected by PVL, who developed two metachronous oral verrucous carcinomas at different sites of the oral mucosa. Owing to the high risk of multiple oral squamous cell carcinoma, periodical clinical and histopathological follow-up is mandatory and should continue lifelong.

Oral leukoplakia diagnosis and treatment in Europe and Australia: Oral Medicine Practitioners' attitudes and practice

The management of oral potentially malignant disorders (OPMD) including oral leukoplakia (OL) is not currently structured according to agreed guidelines. The current report presents survey data gathered from Oral Medicine Practitioners (OMPs) in Europe and Australia and is aimed to investigate attitudes and practice in the diagnosis, risk stratification and treatment of OL. In the presence of a clinical provisional diagnosis of OL, respondents reported always undertaking biopsy in 83% of cases, with most OMPs also relying on diagnostic adjuncts. The potential for malignant transformation is almost invariably assessed through epithelial dysplasia status, with other biomarkers described in the literature used less often. Active treatment of OL was considered mandatory by 20% of OMPs, while others reserve treatment for selected cases only. OMPs are mostly driven to active treatment by lesion-related features which are frequently jointly considered including lesion site, clinical appearance and dysplasia status. Inconsistent assessment was observed regarding mild dysplasia, lesion size, presence of unavoidable trauma, exposure to tobacco and patient age. Frequently observed geographical variations were seldom statistically significant. In agreement with previous surveys, a lack of consensus around the management of OL was observed, supporting claims from learned academies and societies for treatment guidelines aiming to reduce inter-practitioner variability.

Molecular Signatures of Tumour and Its Microenvironment for Precise Quantitative Diagnosis of Oral Squamous Cell Carcinoma: An International Multi-Cohort Diagnostic Validation Study

BACKGROUND

Heterogeneity in oral potentially malignant disorder (OPMD) poses a problem for accurate prognosis that impacts on treatment strategy and patient outcome. A holistic assessment based on gene expression signatures from both the tumour cells and their microenvironment is necessary to provide a more precise prognostic assessment than just tumour cell signatures alone.

METHODS

We reformulated our previously established multigene qPCR test, quantitative Malignancy Index Diagnostic System (qMIDS) with new genes involved in matrix/stroma and immune modulation of the tumour microenvironment. An algorithm calculates and converts a panel of 16 gene mRNA expression levels into a qMIDS index to quantify risk of malignancy for each sample.

RESULTS

The new qMIDS^V2 assay was validated in a UK oral squamous cell carcinoma (OSCC) cohort (n = 282) of margin and tumour core samples demonstrating significantly better diagnostic performance (AUC = 0.945) compared to previous qMIDS^V1 (AUC = 0.759). Performance of qMIDS^V2 were independently validated in Chinese (n = 35; AUC = 0.928) and Indian (n = 95; AUC = 0.932) OSCC cohorts. Further, 5-year retrospective analysis on an Indian dysplastic lesion cohort (n = 30) showed that qMIDS^V2 was able to significantly differentiate between lesions without transformation and those with malignant transformation.

CONCLUSIONS

This study validated a novel multi-gene qPCR test on a total of 535 tissue specimens from UK, China and India, demonstrating a rapid minimally invasive method that has a potential application for dysplasia risk stratification. Further study is required to establish if qMIDS^V2 could be used to improve OPMD patient management, guide treatment strategy and reduce oral cancer burden.

Oral Potentially Malignant Disorders

Oral potentially malignant disorders (OPMDs) are precursor lesions that may undergo malignant transformation to oral cancer. These lesions most commonly present clinically as white patches (leukoplakia). However, they may also be red (erythroplakia), or red and white (erythroleukoplakia). There are many risk factors associated with the development of an OPMD, and with the risk of malignant transformation of the lesion. A biopsy with subsequent microscopic examination from the lesional tissue is necessary in identification of OPMD. This article reviews the clinical appearance of OPMDs, associated risk factors, diagnosis and histologic appearance, and treatment.

Perspectives on oral squamous cell carcinoma prevention-proliferation, position, progression and prediction

Squamous cell carcinoma arising from oral mucosal epithelium remains a lethal and deforming disease due to tumour invasion, oro-facial destruction, cervical lymph node metastasis and ultimate blood-borne dissemination. Worldwide, 300 000 new cases are seen each year, with a recent and significant rise in incidence affecting particularly the young. To rationalize perspectives on preventive strategies in oral cancer management, this study addresses a number of fundamental questions regarding carcinogenesis: proliferation-what epithelial cell changes precede tumour development? Position-why are certain oral sites so predisposed to cancer? Progression-why do some precursor lesions progress to invasive carcinoma and others do not? Prediction-how can we predict individual patient and/or lesion behaviour to prevent disease progression? By improving our understanding of oral carcinogenesis, can we thereby facilitate more effective primary, secondary and tertiary preventive strategies and ultimately reduce the global burden of oral squamous cell carcinoma (OSCC)?

Potentially malignant disorders revisited-The lichenoid lesion/proliferative verrucous leukoplakia conundrum

BACKGROUND

Clinically identifiable potentially malignant disorders (PMD) precede oral squamous cell carcinoma development. Oral lichenoid lesions (OLL) and proliferative verrucous leukoplakia (PVL) are specific precursor lesions believed to exhibit both treatment resistance and a high risk of malignant transformation (MT).

METHODS

A retrospective review of 590 PMD patients treated in Northern England by CO₂ laser surgery between 1996 and 2014 was carried out. Lesions exhibiting lichenoid or proliferative verrucous features were identified from the patient database and their clinicopathological features and outcome post-treatment determined at the study census date of 31 December 2014.

RESULTS

One hundred and 98 patients were identified as follows: 118 OLL and 80 PVL, most frequently leukoplakia at ventrolateral tongue and floor of mouth sites, equally distributed between males and females. Most exhibited dysplasia on incision biopsy (72% OLL; 85% PVL) and were treated by laser excision rather than ablation (88.1% OLL; 86.25% PVL). OLL were more common in younger patients (OLL 57.1 year; PVL 62.25 years; P = .008) and more likely than PVL to present as erythroleukoplakia (OLL 15.3%; PVL 2.5%; P = .003). Whilst no significant difference was seen between OLL and PVL achieving disease-free status (69.5% and 65%, respectively; P = .55), this was less than the overall PMD cohort (74.2%). MT was identified in 2 OLL (1.7%) and 2 PVL (2.5%) during follow-up.

CONCLUSION

One-third of PMD cases showed features of OLL or PVL, probably representing a disease presentation continuum. Post-treatment disease-free status was less common in OLL and PVL, although MT was infrequent.

Evaluation and Management of Oral Potentially Malignant Disorders

Oral potentially malignant disorders (OPMDs) refer to epithelial lesions and conditions with an increased risk for malignant transformation; oral leukoplakia is the most commonly encountered. Overall, OPMDs have a low risk for malignant transformation, yet the challenge is the difficulty to reliably identify and predict which patients with OPMDs are at the highest risk for malignant transformation. Future research is needed to elucidate the molecular aspects of OPMDs, to improve current diagnostic strategies, leading to personalized management.

Treatment resistance in potentially malignant disorders-'Nature' or 'Nurture'…?

BACKGROUND

Contemporary potentially malignant disorder management is based upon provisional histological diagnosis followed by interventional surgery to excise or ablate 'high-risk' mucosal lesions. Although the majority of patients achieve disease-free status post-treatment, others develop further or persistent disease unresponsive to intervention.

METHODS

A detailed, retrospective clinico-pathological review of treatment resistant potentially malignant lesions, from a 590 patient cohort treated by CO₂ laser surgery and followed for a mean of 7.3 years, was undertaken. Clinical outcome was determined at study census date (31 December 2014).

RESULTS

A total of 87 patients (15%) exhibited PMD disease resistant to treatment: 34 (6%) became disease free following further treatment, whilst 53 (9%) had persistent disease despite intervention. Disease-free patients were younger, changed lesion appearance from erythroleukoplakia to leukoplakia (P = .004), developed further lesions at new sites, demonstrated reduction in dysplasia severity with time and required multiple treatments to achieve disease-free status (P = .0005). In contrast, persistent disease patients were older, male, often presented with proliferative verrucous leukoplakia (PVL) on gingival and alveolar sites, displayed less severe dysplasia initially and underwent laser ablation rather than excision (P = .027).

CONCLUSION

Despite clinico-pathological profiling of treatment resistant patients, the precise inter-relationship between the inherent nature of potentially malignant disease and the external influence of treatment intervention remains obscure.

Independent evaluation of a FOXM1-based quantitative malignancy diagnostic system (qMIDS) on head and neck squamous cell carcinomas

The forkhead box M1 (FOXM1) transcription factor gene has been implicated in almost all human cancer types. It would be an ideal biomarker for cancer detection but, to date, its translation into a cancer diagnostic tool is yet to materialise. The quantitative Malignancy Index Diagnostic System (qMIDS) was the first FOXM1 oncogene-based diagnostic test developed for quantifying squamous cell carcinoma aggressiveness. The test was originally validated using head and neck squamous cell carcinomas (HNSCC) from European patients. The HNSCC gene expression signature across geographical and ethnic differences is unknown. This is the first study evaluated the FOXM1-based qMIDS test using HNSCC specimens donated by ethnic Chinese patients. We tested 50 Chinese HNSCC patients and 18 healthy subjects donated 68 tissues in total. qMIDS scores from the Chinese cohort were compared with the European datasets (n = 228). The median ± SD scores for the Chinese cohort were 1.13 ± 0.66, 4.02 ± 1.66 and 5.83 ± 3.13 in healthy oral tissues, adjacent tumour margin and HNSCC core tissue, respectively. Diagnostic test efficiency between the Chinese and European datasets was almost identical. Consistent with previous European data, qMIDS scores for HNSCC samples were not influenced by gender or age. The degree of HNSCC differentiation, clinical stage and lymphatic metastasis status were found to be correlated with qMIDS scores. This study provided the first evidence that the pathophysiology of HNSCC was molecularly indistinguishable between the Chinese and European specimens. The qMIDS test robustly quantifies a universal FOXM1-driven oncogenic program, at least in HNSCC, which transcends ethnicity, age, gender and geographic origins.

Managing oral potentially malignant disorders:A question of risk

The concept of an oral disease process that presents as a ‘potentially malignant state’ that is neither entirely benign nor frankly malignant is a difficult concept both for clinicians and their affected patients. While it is recognised that a range of oral mucosal conditions, now collectively termed ‘potentially malignant disorders’, harbour an increased risk of squamous carcinoma, we remain frustratingly unable in contemporary clinical practice to predict individual lesion behaviour, quantify the risk of malignant transformation or objectively plan interventions.