Department of Urology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA.
Department of Urology, New York University, New York, NY, USA.
Eur Urol Oncol. 2021 Oct;4(5):766-783. doi: 10.1016/j.euo.2020.02.004. Epub 2020 Mar 16.
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. These toxicants are metabolized and excreted in the urine, and may have oncogenic implications for bladder urothelium.
To characterize and summarize known urinary carcinogenic biomarkers in e-cigarette users as they relate to the risk of developing bladder cancer.
A systematic literature search was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and included PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL). Relevant articles published in peer-reviewed journals, through January 2019, 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.
Our initial search identified 1385 articles, 22 of which met final inclusion criteria and were included for analysis. In summation, these studies described 40 different parent compounds and four 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 with nonuser controls, e-cigarette users had higher concentrations of urinary biomarkers of several carcinogenic compounds linked to bladder cancer. The majority of studies were limited by heterogeneous reporting and a dearth of control individuals who had never smoked.
Biomarkers of carcinogens, several with a strong link to bladder cancer, are present in the urine of e-cigarette users. Long-term implications of urothelial exposure to these toxicants are unknown but concerning, given the similarities to tobacco smoke and its established relationship with bladder cancer. Further study on the urological safety of e-cigarettes is necessary.
Our review shows that several carcinogens that have a known link to bladder cancer are present in the urine of electronic cigarette (e-cigarette) users. Further study on the urological safety of e-cigarettes is necessary.
尽管电子香烟（电子烟）的长期健康影响尚不清楚，但它的使用仍迅速增加。电子烟曾经被认为是比烟草烟雾更安全的替代品，但电子烟在蒸气过程中可能会使使用者接触到类似的致癌副产品。这些有毒物质在尿液中被代谢和排泄，并且可能对膀胱尿路上皮具有致癌作用。
描述并总结电子烟使用者尿液中已知的致癌生物标志物，以了解它们与膀胱癌发病风险的关系。
使用系统评价和荟萃分析的首选报告项目（PRISMA）指南进行了系统文献检索，并包括 PubMed、Embase、Web of Science 和 Cochrane 中央对照试验注册（CENTRAL）。纳入了发表在同行评议期刊上的、截至 2019 年 1 月报告电子烟使用者尿液生物标志物的相关文章。根据国际癌症研究机构（IARC）专论对人类致癌风险评估的分类，将母体化合物和尿液生物标志物进行分类，并使用协同健康和环境、毒物和疾病数据库进行交叉引用，以确定与膀胱癌的联系，并根据证据强度进行分组。
我们最初的搜索确定了 1385 篇文章，其中 22 篇符合最终纳入标准并被纳入分析。总的来说，这些研究描述了 40 种不同的母体化合物和 4 种在电子烟使用者尿液中发现的金属。由于每种母体化合物可以被代谢成几种不同的方式，因此鉴定出 63 种独特的有毒或致癌代谢物生物标志物。与非使用者对照相比，电子烟使用者尿液中几种与膀胱癌相关的致癌化合物的生物标志物浓度更高。大多数研究受到报告方式的异质性以及从未吸烟的对照个体数量稀少的限制。
致癌生物标志物，其中一些与膀胱癌有很强的联系，存在于电子烟使用者的尿液中。这些有毒物质对尿路上皮的长期影响尚不清楚，但令人担忧，因为它们与烟草烟雾相似，并且与膀胱癌有明确的关系。需要进一步研究电子烟的泌尿科安全性。
我们的综述表明，几种已知与膀胱癌相关的致癌物质存在于电子烟使用者的尿液中。需要进一步研究电子烟的泌尿科安全性。
