AUA 2017: E-Cigarette Smoke is potentially Bladder Carcinogenic- It Induces Tumorigenic DNA Adducts and Inhibits DNA Repair in Urothelial Cells

Boston, MA ( Since its introduction 2006 the popularity of the E-Cigarettes (ECE) in the US has exploded with approximately 12.6% of adults in the US reporting having tried an ECE. The naïve sense that ECE are safer than regular cigarettes has led a significant shift from regular tobacco cigarette use to smokeless tobacco without much evidence in regards to the its safety profile. More concerning is the rising use of smokeless tobacco by teenagers which lead the CDC to release a nationwide warning in 2014.

Dr. Moon-Shong Tang, from NYU School of Medicine, presents his work on the potential carcinogenic effect of smokeless cigarettes on the bladder. Dr. Tang explains although smokeless cigarettes are mostly concentrated nicotine; nicotine at high concentrations can be converted into nitrosamine compounds by a process called nitrosation. Nitrosamine compounds are well known urothelium carcinogens linked to the formation of bladder cancer in smokers. Since 90% of nicotine and its by-products are excreted by the kidneys the bladder is a perfect experimental model to for the study.

The study was performed in 20 mice which were randomized to ECE (10mg/ml) or filtered air. Using immunochemical methods and high performance liquid chromatography (HPLC) the urine was tested for common tobacco related carcinogens. DNA repair activity was assessed by an in vitro DNA-damage-dependent repair synthesis method and mutational susceptibility was determined with the supF system.

Mice exposed of ECS had high concentrations of y-OH-PdG and 0-meth-dg adducts which are known carcinogens. Evidence of both DNA repair disruption and high mutation profiles were seen in the treated group.

In conclusion, E-Cigarettes have the potential to be carcinogenic to the bladder urothelium by induction of DNA damage and inhibition of DNA repair. More work needs to be done to validate this findings and asses if there is a dose dependent phenomenon as with regular tobacco. This findings are of great concern given the popularity of E-Cigarettes in adults and teenagers. If guidelines and warnings are not set in place we may be facing another cancer epidemic.

Presented By: Moon-Shong Tang, PhD

Institution: NYU School of Medicine

Written By: Andres F. Correa, Society of Urologic Oncology Fellow, Fox Chase Cancer Center, Philadelphia, PA

at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA