Introduction:
Use of electronic cigarettes (e-cigarettes) has rapidly increased despite unclear longitudinal health effects. Once thought to be a safer alternative to tobacco smoke, it is possible that e-cigarettes expose the user to similar carcinogenic byproducts during the vaping process, potentially placing users as risk for bladder cancer.

Objectives:
To characterize the institutional data, population weighted studies, as well as translational and basic science findings of e-cigarette use as it relates to the potential risk of bladder cancer.

Methods:
Literature review.

Results:
Up to 8% of bladder cancer survivors use e-cigarettes. Cancer survivors commonly perceive e-cigarettes to be as much or more harmful than traditional cigarettes. Six carcinogens that have a known strong link to bladder cancer have been identified in the urine of e-cigarette users (pyrene, naphthalene, fluorene, phenanthrene, o-toluidine, and 2-naphthylamine). Untargeted metabolomics of the urine of e-cigarette users have demonstrated the cancer related biomarker Me-Fapy and genotoxic MNPB in the urine of e-cigarettes users at levels higher than non-user controls. Patterns in methylation appears to be altered in vaped mice within tumor suppressor genes (protocadherin gene cluster), potentially leading to gene silencing which may play a fundamental role in precipitating the development of bladder cancer.

Conclusions:
Long-term implications of chronic urothelial exposure to urinary carcinogens of e-cigarette users are unknown and will require long-term follow-up. However, the current data and literature provides a useful scientific rationale to consider the carcinogenic-specific aspects of using e-cigarettes. The malignant potential of e-cigarettes for bladder cancer remains unknown and is likely less than that of combustible cigarettes.