Vaping, Environmental Toxicants Exposure, and Lung Cancer Risk

Abstract

Lung cancer (LC) is the second-most prevalent tumor worldwide. According to the most recent GLOBOCAN data, over 2.2 million LC cases were reported in 2020, with an estimated new death incident of 1,796,144 lung cancer cases. Genetic, lifestyle, and environmental exposure play an important role as risk factors for LC. E-cigarette, or vaping, products (EVPs) use has been dramatically increasing world-wide. There is growing concern that EVPs consumption may increase the risk of LC because EVPs contain several proven carcinogenic compounds. However, the relationship between EVPs and LC is not well established. E-cigarette contains nicotine derivatives (e.g., nitrosnornicotine, nitrosamine ketone), heavy metals (including organometal compounds), polycyclic aromatic hydrocarbons, and flavorings (aldehydes and complex organics). Several environmental toxicants have been proven to contribute to LC. Proven and plausible environmental carcinogens could be physical (ionizing and non-ionizing radiation), chemicals (such as asbestos, formaldehyde, and dioxins), and heavy metals (such as cobalt, arsenic, cadmium, chromium, and nickel). Air pollution, especially particulate matter (PM) emitted from vehicles and industrial exhausts, is linked with LC. Although extensive environmental exposure prevention policies and smoking reduction strategies have been adopted globally, the dangers remain. Combined, both EVPs and toxic environmental exposures may demonstrate significant synergistic oncogenicity. This review aims to analyze the current publications on the importance of the relationship between EVPs consumption and environmental toxicants in the pathogenesis of LC.

Keywords: cancer; e-smoking; electronic cigarette; environment; pulmonary; risk; vaping.

Figure 1

Vaping products and environmental toxicants exposure and lung cancer risk.

Figure 2

Histological classification of lung cancer (LC); Small-cell Lung Cancer (SCLC); Non-small cell Lung Cancer (NSCLC); Adenocarcinoma (LUAD); Squamous-cell Carcinoma (LUSC) and Large-cell Carcinoma (LCC).

Figure 3

Relationship between using vape and rise of environmental toxicants exposure.

Figure 4

Mechanisms of environmental toxicants causing lung cancer. DNAdsb: double-strand DNA breaks, ROS: reactive oxygen species, NF-κB: nuclear factor kappa B, Nrf2: nuclear factor erythroid 2–related factor 2, IL-1/6 interleukin-1/6, TNF-α: tumor necrosis factor-alpha, Caspase: cysteine-dependent aspartate-directed proteases, CAT: Catalase, MDA: malondialdehyde, TAC: Total antioxidant capacity.