Potentially malignant disorders of the oral cavity: Current practice and future directions in the clinic and laboratory

Abstract

Despite commendable progress in the prevention, detection, and treatment of a wide variety of solid tumor types, oral squamous cell carcinoma (OSCC) remains a significant health burden across the globe. OSCC carcinogenesis involves accumulation of genetic alterations that coincide with the multistep malignant transformation of normal oral epithelium. OSCC is often first diagnosed at late stages of the disease (advanced regional disease and/or metastasis). Delayed diagnosis precludes successful treatment and favorable outcomes. In clinical practice, opportunities exist to identify patients with oral potentially malignant disorders (OPMDs), which precede the development of cancer. This review addresses the current status of laboratory and clinical research on OPMDs, with emphasis on leukoplakia and erythroplakia. OSF is also presented, though there is a paucity of published studies on this disorder. We focus on findings that could translate into earlier diagnosis and more efficacious treatment of those lesions with significant malignant potential. We explore how markers of OPMD malignant transformation might be implemented into current diagnostic practice to help clinicians objectively stratify patients into treatment/follow-up groups according to relative risk. We provide an overview of recently concluded and ongoing OPMD chemoprevention trials. We describe laboratory OPMD models that can be used to not only to reveal the genetic and molecular intricacies of oral cancer but also to develop novel screening methods and therapeutic approaches. Finally, we call for targeted screening programs of at-risk populations in order to facilitate diagnosis and treatment of OPMD and early OSCC.Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with 600,000 new cases reported annually. 1,2 Approximately half of these cases present as squamous cell carcinoma on the lip or within the oral cavity. 3 While the detection and treatment of most malignancies has improved over the last several decades, the prognosis associated with oral squamous cell carcinoma (OSCC) has remained unchanged. [4][5][6] As a result, more than 120,000 deaths can be attributed to OSCC per annum. 7 Oral cancer does not currently satisfy criteria for a screenable disease, 8 however, theory 9 suggests that most cases are preceded by asymptomatic clinical lesions collectively referred to as oral potentially malignant disorders (OPMDs). 10 Herein, we review basic and clinical research on OPMDs and suggest possible approaches to effectively address this public health burden. Particular attention is placed on how understanding OPMD might translate into earlier diagnosis and more efficacious treatment. Nomenclature and EpidemiologyThere are several OPMDs that precede the development of OSCC. Those most commonly encountered are erythroplakia

Treatment of oral leukoplakia with a low‐dose of beta‐carotene and vitamin C supplements: A randomized controlled trial

“…The less promising results of the randomized, placebo-controlled chemoprevention trials and further development of dietary chemoprevention agents were recently discussed. 47 Of note, a meta-analysis on beta-carotene supplementation and cancer risk (published after the authors commenced this RCT) reported on the absence of any protective effect associated with supplementation for various sites with regard to cancer risk. 49 Data from this study does not support the recommendation of beta-carotene combined with vitamin C for the chemoprevention of oral cancer when tested on otherwise healthy subjects living in well-nourished countries.…”

CD24 blunts oral squamous cancer development and dampens the functional expansion of myeloid-derived suppressor cells

“…3 Oral cancer carcinogenesis involves the accumulation of genetic alterations leading to the multistep malignant transformation of normal oral epithelial cells. 4 Currently, the exact mechanism is unclear; thus, further understanding and identification of factors that initiate disease and modify disease outcomes, such as immune-cancer interactions and interplay between oral bacteria and host immune responses, will contribute to better prevention and patient treatment.…”

Tanshinones in management of oral submucous fibrosis and oral squamous cell carcinoma

“…[2] OSMF has the potential to progress to oral squamous cell carcinoma (OSCC). [3] Every year, OSCC is estimated to occur in more than 400,000 people worldwide. [4] Every year, 120,000 deaths occur due to OSCC.…”

“…[4] Every year, 120,000 deaths occur due to OSCC. [3] Currently, there are several modes of management of OSCC and OSMF, depending upon the stage of the disease and several other factors. The 5-year survival of OSCC patients still remains to be 50%.…”