E-cigarette: a safe tool or a risk factor for oral cancer? A systematic review

Electronic cigarettes (e-cigarettes) are considered relatively safe, thus tobacco and nicotine delivery products have become popular in the last few years. However, the safety of long-term use of these products on oral health is still questionable. E-cigarettes may have potential risks to oral health that can be demonstrated as cellular damage, genetic instability, and mucosal lesions. This review aims to observe the role of e-cigarettes as a risk factor for oral cancer development.

This systematic review was conducted following the PRISMA guidelines to provide reliable data on the role of electronic cigarettes as a risk factor for oral cancer development. The research was performed on Pubmed and Scopus by three reviewers from the Oral Pathology Department (Sapienza University of Rome) in May 2024. The search terms included: "e-cigarette", "oral cancer", and "risk factor" where 32 articles from PubMed and 75 from Scopus were collected. A total of 12 studies met the eligibility criteria: 6 clinical studies and 6 in vitro. All the included studies were subjected to quality assessment and data extraction processes. The risk of bias assessment of in vitro studies revealed low or unknown risk. None of the studies had any industrial sponsoring and almost all the papers (90%) had the same methods, 64% measured the cell vitality. The qualitative analysis was done for all the included clinical studies using the RoB assessment tool (MINORS). The range of the total RoB score in the comparative studies was between 12 and 23.

The clinical studies involved a total of 413 participants were also included. Most studies did not specify the age and gender of participants and patients were divided into three main groups based on specific criteria: non-smokers, smokers, and e-cigarette users. These studies highlighted cases of mucosal lesions and genetic instability associated with e-cigarette use.

However, the limited long-term data and conflicting results emphasize the need for a larger number of studies, such as randomized controlled trials and cohort studies, to acquire more data about the safety and risks associated with e-cigarettes. Key words:E-cigarettes, squamous cell carcinoma, oral oncology, smoking.