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

Premalignant lesions of the oral cavity: a narrative review of factors and mechanisms of transformation into cancer

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck cancer. The development and progression of OSCC are closely linked to various aetiological factors. Early signs of OSCC may manifest as oral lesions, genetic abnormalities, and chronic inflammation. Lesions with dysplastic features have a high risk of malignant transformation into OSCC. Moreover, dysplastic lesions are characteristic of many oral potentially malignant disorders (OPMDs). Currently, there is no unified standard of treatment for OPMD patients, due to the variability in risk factors and mechanisms of transformation. Therefore, it is essential to detect and manage OPMDs at an early stage in order to prevent their malignant transformation into OSCC. This necessitates analysing OPMD mechanisms to identify objective markers for predicting the risk of malignant transformation. The aim of this review was to describe the process of OPMD transformation into OSCC under the influence of environmental, immune, microbiome, and molecular factors.

Challenges and improvements in multi-layer mucosa-adhesive films for oral diseases treatment and prognosis

Due to the complexity of oral physiology and pathology, the treatment of oral diseases faces multiple and complex clinical requirements. Mucosa-adhesive films (MAFs) with a single layer have demonstrated considerable potential in delivering therapeutic bioactive ingredients directly to the site of oral diseases. However, their functions are often hindered by certain factors such as limited loading capacity, poor site specificity, and sensitivity to mechanical stimuli. To overcome these limitations, the development of multi-layer MAFs has become a focal point for recent research. This involves the improvement of construction methods for multi-layer MAFs to minimize potential health risks from residual solvents, and conducting comprehensive in vivo studies to evaluate their safety and therapeutic efficacy more accurately, thus paving the way for their commercialization. Additionally, the exploration of multi-layer MAFs as personalized drug delivery systems could further broaden their application prospect. Precisely, multi-layer MAFs compensate for the shortcomings of current therapeutic strategies for oral diseases to a great extent, indicating a promising future in the market.

Potential of melatonin to reverse epigenetic aberrations in oral cancer: new findings

It is now an accepted principle that epigenetic alterations cause cellular dyshomeostasis and functional changes, both of which are essential for the initiation and completion of the tumor cycle. Oral carcinogenesis is no exception in this regard, as most of the tumors in the different subsites of the oral cavity arise from the cross-reaction between (epi)genetic inheritance and the huge challenge of environmental stressors. Currently, the biochemical machinery is put at the service of the tumor program, halting the cell cycle, triggering uncontrolled proliferation, driving angiogenesis and resistance to apoptosis, until the archetypes of the tumor phenotype are reached. Melatonin has the ability to dynamically affect the epigenetic code. It has become accepted that melatonin can reverse (epi)genetic aberrations present in oral and other cancers, suggesting the possibility of enhancing the oncostatic capacity of standard multimodal treatments by incorporating this indolamine as an adjuvant. First steps in this direction confirm the potential of melatonin as a countermeasure to mitigate the detrimental side effects of conventional first-line radiochemotherapy. This single effect could produce synergies of extraordinary clinical importance, allowing doses to be increased and treatments not to be interrupted, ultimately improving patients' quality of life and prognosis. Motivated by the urgency of improving the medical management of oral cancer, many authors advocate moving from in vitro and preclinical research, where the bulk of melatonin cancer research is concentrated, to systematic randomized clinical trials on large cohorts. Recognizing the challenge to improve the clinical management of cancer, our motivation is to encourage comprehensive and robust research to reveal the clinical potential of melatonin in oral cancer control. To improve the outcome and quality of life of patients with oral cancer, here we provide the latest evidence of the oncolytic activity that melatonin can achieve by manipulating epigenetic patterns in oronasopharyngeal tissue.

Progression to malignancy in oral potentially malignant disorders: a retrospective study of 5,036 patients in Ontario, Canada

OBJECTIVES

Determine the rate of malignant transformation (MT) of oral potentially malignant disorders (OPMDs) and risk factors for transformation.

STUDY DESIGN

The OPMD database (2001-2015) from 2 biopsy services in Ontario, Canada, was linked to the Ontario Cancer Registry to determine the rate of progression to oral squamous cell carcinoma (OSCC). Clinical and histologic features of progressed and non-progressed cases were compared to determine risk factors for progression.

RESULTS

The MT rate was 6.4% (322/5,036 cases). The mean time for cancer development was 51.2 months. 33.6% of cases (107/322) progressed after over 60 months. The risk of cancer increased with age and was higher in non-smokers. The MT rate was highest in the tongue (11.4%), followed by the floor of mouth (7.1%) and gingiva (6.5%). Histologic grade was associated with progression to cancer (P < .0001). Atypical verrucous-papillary lesions with no or mild dysplasia predominantly affected older patients' gingiva, and the progression rate was significantly higher than conventional mild dysplasia (9.2% vs 3.2%, P = .0002).

CONCLUSIONS

Our population-based retrospective study showed that <10% of OPMDs progressed to cancer, which could take many years. Atypical papillary-verrucous proliferation without high-grade dysplasia is a subtype of OPMD requiring further study.

American Association of Oral and Maxillofacial Surgeon's Position Paper on Oral Mucosal Dysplasia R2

Oral potentially malignant disorders (OPMDs) of the oral mucosa include leukoplakia, erythroplakia, erythroleukoplakia, lichen planus, and oral lichenoid lesions, each with varying incidences of dysplastic disease at the time of presentation and each with observed incidences of malignant transformation over time. The primary goal of the management of dysplasia, therefore, includes their early detection and treatment prior to malignant transformation. The recognition and management of these OPMDs and an understanding of their potential progression to oral squamous cell carcinoma will reduce the morbidity and mortality associated with these lesions with expedient and properly executed treatment strategies that will have a positive effect on patient survival. It is the purpose of this position paper to discuss oral mucosal dysplasia in terms of its nomenclature, epidemiology, types, natural history, and treatment to acquaint clinicians regarding the timing of biopsy, type of biopsy, and follow-up of patients with these lesions of the oral mucosa. This position paper represents a synthesis of existing literature on this topic with the intention of closing gaps in our understanding of oral mucosal dysplasia while also stimulating new thinking to guide clinicians in the proper diagnosis and management of OPMDs. The fifth edition of the World Health Organization classification of head and neck tumors published in 2022 represents new information regarding this topic and a construct for this position paper.

Designing a Mucoadhesive ChemoPatch to Ablate Oral Dysplasia for Cancer Prevention

Oral cancer has a high mortality rate, and its treatment often causes debilitating complications. More than 90% of oral cancers are oral squamous cell carcinomas (OSCCs) that may develop from clinically recognizable oral premalignant lesions (OPLs). To eradicate OPLs before they turn into cancers, a non-invasive topical formulation is developed based on a novel combination of synergistically acting oxaliplatin (OXP) and mycophenolate (MPS) embedded in a controlled-release mucoadhesive patch fabricated by computer-aided 3D printing. After multiple rounds of testing and optimization, a v6.4 ChemoPatch is designed, which shows sustained release of OXP and MPS in vitro, minimal side leakage of drugs, an average elastic modulus of 2.38 MPa, and suitable drug stability at 4 °C or below for up to 12 months. In vivo analyses show almost all patches adhere to the dorsal tongue surface for 4 hours, and display a sustained release of OXP and MPS to tongue tissue for 3-4 hours. When applied in the 4-nitroquinoline-1-oxide-induced OPL rat model, the OXP-MPS patch significantly ablates dysplastic lesions with no damage to normal epithelial cells and minimal systemic absorption and side effects. This study reports the design of a novel mucoadhesive ChemoPatch as a noninvasive therapy to treat OPLs.