A new study published in International Urology and Nephrology has found strong links between conventional cigarette smoking and urogenital cancers such as bladder cancer, while the long-term cancer risks of e-cigarettes remain uncertain and require further investigation.
Researchers analyzed data from 88,701 adults in the United States who took part in the National Health Interview Survey between 2020 and 2022. Among them, 326 participants had bladder cancer and 1,399 had prostate cancer. The study aimed to compare the associations between traditional cigarette smoking, e-cigarette use and the development of these cancers.
After adjusting for multiple health and demographic factors, the researchers found a strong association between conventional cigarette smoking with both cancers. Smokers had nearly four times higher odds of bladder cancer and a 42% increase in the odds of prostate cancer compared with nonsmokers.
E-cigarettes produced more complex results. Initial analyses showed an apparent inverse association between vaping and both cancers. However, after adjusting for factors such as age and comorbidities, the association remained significant only for bladder cancer and disappeared for prostate cancer. Researchers cautioned that this finding likely reflects differences in the populations who use e-cigarettes, who tend to be younger and have fewer health conditions, rather than a protective effect from e-cigarettes themselves.
The authors also stressed that the absence of a clear link between e-cigarettes and cancer should not be interpreted as evidence of safety. E-cigarette aerosols contain carcinogenic substances such as formaldehyde, acetaldehyde and heavy metals, and biomarker studies have detected cancer-related chemicals in the urine of e-cigarette users. Because vaping products are relatively new, long-term epidemiological data about their use remain limited.
The study also identified other health conditions that appear to contribute to urogenital cancer risk. Hypertension (high blood pressure) and diabetes were independently associated with higher odds of bladder cancer, while age, hypertension and obesity were linked to increased prostate cancer risk.
Read more about bladder cancer causes and risk factors
The researchers concluded that longitudinal studies with more detailed exposure tracking are needed to determine whether e-cigarette use contributes to urogenital cancer risk over time. In the meantime, the findings suggest several lifestyle modifications present key opportunities for cancer prevention.
“Multidisciplinary prevention strategies targeting smoking cessation, blood pressure control, and glycemic control may together reduce the burden of urogenital cancers,” the authors concluded.
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