PD50-05 CARCINOGEN BIOMARKERS IN THE URINE OF ELECTRONIC-CIGARETTE USERS AND IMPLICATIONS FOR POTENTIAL BLADDER CANCER

Abstract

INTRODUCTION AND OBJECTIVE: Use of 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. These toxicants are metabolized and excreted in the urine and may have oncogenic implications for bladder urothelium. This review characterizes and summarizes known urinary carcinogenic biomarkers in e-cigarette users as they relate to the risk of developing bladder cancer. METHODS: A systematic literature search was performed using PRISMA guidelines. Relevant articles published in peer-reviewed journals that reported on urinary biomarkers in e-cigarettes users were included. Parent compounds and urinary biomarkers were classified according to the International Agency for Research on Cancer Monographs on the Evaluation of Carcinogenic Risks to Humans and cross referenced using the Collaborative on Health and the Environment, Toxicant and Disease Database to determine a link to bladder cancer, grouped by strength of evidence. RESULTS: Our initial search identified 1,385 articles, 22 of which met final inclusion criteria and were included for analysis. In summation, these studies described 40 different parent compounds and 4 metals found in the urine of e-cigarette users. Since each parent compound can be metabolized several different ways, 63 unique toxicant or carcinogenic metabolite biomarkers were identified. Compared to non-user controls, e-cigarette users had higher concentrations of urinary biomarker of several carcinogenic compounds linked to bladder cancer (Table 1). The majority of studies were limited by heterogeneous reporting and a dearth of control subjects who had never smoked. CONCLUSIONS: Biomarkers of carcinogens, several with a strong link to bladder cancer, are present in the urine of e-cigarettes users. The long term implications of urothelial exposure to these toxicants is unknown but concerning given the similarities to tobacco smoke and its established relationship with bladder cancer. Further study on the urologic safety of e-cigarettes is necessary.Source of Funding: National Center for Advancing Translational Sciences (NCATS), National Institutes of Health, through Grant Award Number UL1TR002489 (MAB), and a New York State ECRIP’s award