The risk of lung cancer from vaping or e-cigarette usage: a systematic review

Background Active tobacco smoking remains the primary etiological factor for lung cancer, the leading cause of cancer-related mortality worldwide. The use of electronic cigarettes (ECs) has recently emerged as a potential public health concern due to its suspected association with respiratory and oncogenic outcomes. This study aimed to evaluate the association between EC use and the incidence of lung cancer through a systematic review of existing scientific literature. Methods A comprehensive literature search was conducted in PubMed, the Cochrane Library, Embase, ScienceDirect, Web of Science, Scopus, and Google Scholar up to June 2024. Original research articles of any study design that reported on the association between vaping or EC use and the risk of lung cancer were included. The quality of studies was assessed using the critical appraisal checklists for studies created by the Joanna Briggs Institute. Findings Of 2252 identified citations, 5 articles were selected for qualitative analysis. These were primarily non-randomised observational designs published between 2019 and 2024. Sample sizes ranged from 3162 to 4 329 288 participants of both genders. A potential association between EC use and the risk of developing lung cancer was observed. Individuals who concurrently use conventional cigarettes and ECs exhibit an increased likelihood of lung cancer incidence. Conclusion This systematic review suggests a potential association between EC use and an increased risk of lung cancer, particularly among dual users; however, causality cannot be established due to heterogeneity and limited longitudinal data.