Risk analysis of malignant potential of oral verrucous hyperplasia: A follow-up study of 269 patients and copy number variation analysis

Molecular landscape of proliferative verrucous leukoplakia: a systematic review

Proliferative verrucous leukoplakia (PVL) is a rare oral potentially malignant disorder characterised by multifocal origin and unpredictable long-term evolution to oral squamous cell carcinoma (OSCC) or oral verrucous carcinoma (OVC). Currently no predictive biomarkers are in clinical use. We aimed to explore the genomic profile of PVL. A total of 685 cases in 26 studies were included in this review. Genomic data were presented in 15% of studies and biomarker analysis was reported in 85% of studies. At first clinical presentation, PVL is characterised by a high loss of heterozygosity (LOH), similar to OSCC, and low copy number alterations (CNA). As these progress, more CNAs and mutations in CDKN2A and alterations to ELAVL1 expression are noted, but no TP53 mutations are identified. There is significantly lower LOH at 17p in early PVL compared with OSCC (p = 0.037). Deletions in chromosomal loci 17q12, 5q31.1 and amplifications in 7q11.2, 7q22 are shared between early lesions and OVC. PVL shows CNAs at 11q31. WNT signalling pathway genes (SUZ12, CTTN and FOLR3) are enriched in CN-altered regions. PVL stroma shows significantly lower α-SMA and higher CD34 expression than OVC and OSCC. The exact genomic landscape is currently unclear, and further studies are necessary to unravel this mystery.

Controversies in verruco papillary lesions of the oral cavity-A systematic review

INTRODUCTION

Verruco papillary lesions (VPL) in the oral cavity encompass a spectrum of lesions starting from benign, potentially malignant to entirely malignant tumors. Much of the controversies in these entities occur due to lack of consensus on the disease characteristics and the management. This systematic review was conducted to identify and describe different lesions categorized as VPL in the oral cavity and their association with malignancy.

METHODS

An electronic literature search was conducted in MEDLINE (via PubMed), Scopus, LILAC, IMSEAR, and CENTRAL databases, which retrieved a total of 1020 abstracts. These abstracts were managed through Rayyan and Mendeley software, and only 28 studies with high quality were included in the systematic review.

RESULTS

Studies were published from 1992 to 2021. From the extracted data, nine different entities under the umbrella term VPL were identified associated with malignancy. We describe the clinical and histopathological characteristics of these and propose a uniform framework for nomenclature.

CONCLUSIONS

Lack of well-planned research with adequate follow-up duration and inadequate quality standards are major barriers for the lack of evidence. The use of uniform nomenclature, as proposed in this study, and research at the molecular level will greatly reduce the controversies in understanding oral VPL associated with malignancy.

Malignant transformation of oral potentially malignant disorders in Taiwanese indigenous peoples: A nationwide retrospective cohort study

Malignant transformation of oral potentially malignant disorders (OPMDs) is a potential cause of oral cancer. Currently, there is no research investigating the rate of malignant transformation of OPMDs into oral cancer in indigenous Taiwanese peoples. This study aimed to retrospectively investigate whether ethnicity (indigenous vs non-indigenous people) plays a role in increasing the malignant transformation rate of OPMDs into oral cancer. This study used data from the oral mucosal screening database and the Cancer Registry File, both of which originated from the National Health Insurance Research Database. We matched the baseline characteristics to control for confounding factors between indigenous peoples and non-indigenous peoples (17,768 indigenous subjects vs 71,072 non-indigenous subjects; 1:4 match) and compared the 2 cohorts. After matching for confounding factors such as age, sex, habits, and OPMD subtype, the malignant transformation rate was not statistically higher for indigenous people than for non-indigenous people. We also discovered that indigenous people with oral verrucous hyperplasia might have a higher chance of malignant transformation into oral cancer than the non-indigenous cohort. We conclude that ethnicity is not a risk factor for the malignant transformation of OPMDs into oral cancer; however, indigenous people with oral verrucous hyperplasia need to pay special attention and are suggested to undergo regular follow-ups for the occurrence of oral cancer.

Areca Nut and Oral Cancer: Evidence from Studies Conducted in Humans

Areca nut chewing is one of the major risk factors for oral cancer, with large-magnitude risks reported in studies comparing betel quid chewers and never users, and it has been evaluated as a group 1 carcinogen by the International Agency for Research on Cancer. Data from a high-quality meta-analysis examining risk estimates are presented in summary form with additional information from more recent studies (pooled adjusted relative risk, 7.9; 95% CI, 7.1 to 8.7). The risk of oral cancer increases in a dose-response manner with the daily number of quids consumed and the number of years chewing. In the Indian subcontinent and in Taiwan, approximately half of oral cancers reported are attributed to betel quid chewing (population attributable fraction, 53.7% for residents in Taiwan and 49.5% for the Indian population), a disease burden that could be prevented. Oral leukoplakia and oral submucous fibrosis are 2 main oral potentially malignant disorders caused by areca nut chewing that can progress to oral cancer with continued use. Ex-chewers seem to demonstrate lower risks than current chewers, but the impact of areca nut cessation on oral cancer risk has not been scientifically evaluated on the basis of randomized controlled studies. These data strongly reconfirm that betel quid chewing, primarily areca nut use, should be taken into account in assessing the cancer risk of South Asian, East Asian populations and Pacific Islanders for the development of oral cancer.

Oral epithelial dysplasia: Recognition, grading and clinical significance

Histopathological grading of epithelial dysplasia remains the principal laboratory method for assessing the risk of malignant transformation in oral potentially malignant disorders (OPMDs). Current views on the molecular pathogenesis and histological interpretation of the features of epithelial dysplasia are described, and the use of grading systems for epithelial dysplasia is discussed. Changes to the current 2017 WHO criteria for diagnosis are proposed with emphasis on the architectural features of epithelial dysplasia. The predictive values of three-grade and binary systems are summarised, and categories of epithelial dysplasia are reviewed, including lichenoid and verrucous lesions, keratosis of unknown significance, HPV-associated dysplasia, differentiated and basaloid epithelial dysplasia. The implications of finding epithelial dysplasia in an oral biopsy for clinical management are discussed from the pathologists' viewpoint.

Oral potentially malignant disorders: A consensus report from an international seminar on nomenclature and classification, convened by the WHO Collaborating Centre for Oral Cancer

Oral potentially malignant disorders (OPMDs) are associated with an increased risk of occurrence of cancers of the lip or oral cavity. This paper presents an updated report on the nomenclature and the classification of OPMDs, based predominantly on their clinical features, following discussions by an expert group at a workshop held by the World Health Organization (WHO) Collaborating Centre for Oral Cancer in the UK. The first workshop held in London in 2005 considered a wide spectrum of disorders under the term "potentially malignant disorders of the oral mucosa" (PMD) (now referred to as oral potentially malignant disorders: OPMD) including leukoplakia, erythroplakia, proliferative verrucous leukoplakia, oral lichen planus, oral submucous fibrosis, palatal lesions in reverse smokers, lupus erythematosus, epidermolysis bullosa, and dyskeratosis congenita. Any new evidence published in the intervening period was considered to make essential changes to the 2007 classification. In the current update, most entities were retained with minor changes to their definition. There is sufficient evidence for an increased risk of oral cancer among patients diagnosed with "oral lichenoid lesions" and among those diagnosed with oral manifestations of 'chronic graft-versus-host disease'. These have now been added to the list of OPMDs. There is, to date, insufficient evidence concerning the malignant potential of chronic hyperplastic candidosis and of oral exophytic verrucous hyperplasia to consider these conditions as OPMDs. Furthermore, due to lack of clear evidence of an OPMD in epidermolysis bullosa this was moved to the category with limited evidence. We recommend the establishment of a global research consortium to further study the natural history of OPMDs based on the classification and nomenclature proposed here. This will require multi-center longitudinal studies with uniform diagnostic criteria to improve the identification and cancer risk stratification of patients with OPMDs, link them to evidence-based interventions, with a goal to facilitate the prevention and management of lip and oral cavity cancer.

Social and behavioural determinants of areca nut consumption in adolescents

OBJECTIVE

This study aimed to investigate the prevalence of areca nut consumption and to identify social and behavioural determinants among a Taiwanese adolescent population.

SUBJECTS AND METHODS

A random sample of 5,343 high school students aged between 15-18 years in Kaohsiung, Taiwan, participated in the study. Participants underwent a clinical dental examination and completed a self-administered questionnaire. Data analyses were performed using multivariate logistic regression to establish a relationship between areca nut consumption as well as social and behavioural characteristics.

RESULTS

The prevalence of areca nut consumption was 3.0%. The chewing habit was more prevalent among older adolescents (p < .001, OR = 1.50, 95% CI: 1.26, 1.78), males (p < .001, OR = 17.91, 95% CI: 8.57, 37.40), pupils living with non-birth parent(s) (p = .003, OR = 2.13, 95% CI: 1.29, 3.50), children of family heads with primary (p = .001, OR = 2.90, 95% CI: 1.50, 5.59) or secondary level of education (p < .001, OR = 2.78, 95% CI: 1.74, 4.46), frequent risk takers (p < .001, OR = 1.35, 95% CI: 1.27, 1.43) and students of low physical fitness (p < .001, OR = 3.65, 95% CI: 1.81, 7.35).

CONCLUSIONS

Areca nut consumption has become an ongoing pertinent issue in adolescent health. Future investigations into neurocognitive influences of risk-taking behaviour on areca nut consumption and social dependence of the habit are indicated.

Malignant development in patients with oral potentially malignant disorders detected through nationwide screening: Outcomes of 5-year follow-up at a single hospital

BACKGROUND

Although survival rate and quality of life are improved if patients with oral carcinoma can be detected early, however, such lesions are usually asymptomatic; therefore, it is hard to raise awareness. Screening has proved to be cost-effective for early detection.

METHODS

Sixty-two patients with oral carcinomas and 555 patients with oral potentially malignant disorders (OPMDs) who were detected through screening were examined the relationship between clinicopathological features and follow-up outcomes.

RESULTS

The 5-year cumulative cancer-free interval rate was 94.1%, and the annual malignant transformation rate was 1.16%. The rate of interval carcinoma development from Candida hyperplasia, oral submucous fibrosis, homogeneous leukoplakia, non-homogenous leukoplakia, and verrucous hyperplasia, was 13.6%, 5.7%, 4.6%, 12.1%, and 21.3%, respectively. Significant independent risk factors for interval carcinoma development were heavy betel quid chewing, verrucous hyperplasia, and surgery refusal.

CONCLUSIONS

Well-designed risk assessment, treatment, and surveillance program could lead to earlier cancer detection and thereby reduce mortality and morbidity.

Selected Golgi-Localized Proteins and Carcinogenesis: What Do We Know?

The role of the Golgi apparatus in carcinogenesis still remains unclear. A number of structural and functional cis-, medial-, and trans-Golgi proteins as well as a complexity of metabolic pathways which they mediate may indicate a central role of the Golgi apparatus in the development and progression of cancer. Pleiotropy of cellular function of the Golgi apparatus makes it a "metabolic heart" or a relay station of a cell, which combines multiple signaling pathways involved in carcinogenesis. Therefore, any damage to or structural abnormality of the Golgi apparatus, causing its fragmentation and/or biochemical dysregulation, results in an up- or downregulation of signaling pathways and may in turn promote tumor progression, as well as local nodal and distant metastases. Three alternative or parallel models of spatial and functional Golgi organization within tumor cells were proposed: (1) compacted Golgi structure, (2) normal Golgi structure with its increased activity, and (3) the Golgi fragmentation with ministacks formation. Regardless of the assumed model, the increased activity of oncogenesis initiators and promoters with inhibition of suppressor proteins results in an increased cell motility and migration, increased angiogenesis, significantly activated trafficking kinetics, proliferation, EMT induction, decreased susceptibility to apoptosis-inducing factors, and modulating immune response to tumor cell antigens. Eventually, this will lead to the increased metastatic potential of cancer cells and an increased risk of lymph node and distant metastases. This chapter provided an overview of the current state of knowledge of selected Golgi proteins, their role in cytophysiology as well as potential involvement in tumorigenesis.

Clinical features and presentation of oral potentially malignant disorders

Oral potentially malignant disorders (OPMDs) are conditions that precede the onset of invasive cancers of the oral cavity. The term embraces precancerous lesions and conditions referred to in earlier World Health Organization (WHO) definitions. Leukoplakia is the most common OPMD; erythroplakia, although rare, is more serious. Several variants of leukoplakia are recognized, and clinical subtyping may help determine the prognosis to a limited extent. Biopsy is essential to confirm the provisional clinical diagnosis, and timely referral to a specialist is indicated. Certain OPMDs, such as oral submucous fibrosis, are encountered particularly in population groups from Asia with specific lifestyle habits. This review provides clinical descriptions of the wide range of potentially malignant disorders encountered in the oral cavity as a prelude to the topics discussed in this focus issue.