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Secondhand Smoke and Bladder Cancer: What’s the Connection?

What if I don’t smoke?

The relationship between bladder cancer and smoking has typically been investigated and tied to the smoking history of the patient. But there is now research that suggests that secondhand smoke also plays a role in increasing the likelihood of developing bladder cancer in non-smokers. The questions investigators have been asking are:

  1. Is exposure to secondhand smoke a confirmed risk factor increasing the rate of developing bladder cancer?
  2. Does exposure to secondhand smoke in childhood contribute to lifetime exposure, resulting in a higher rate of bladder cancer?

The investigators’ approach to answer these questions was to conduct a meta-analysis, an examination of data from previous independent studies on the same subject, designed to determine overall trends in the literature available.

There have been clinical studies that looked to identify the relationship between secondhand smoke and bladder cancer. In earlier reviews, only one report found “a significantly increased risk of secondhand smoke and bladder cancer in nonsmoking population.”1 A new meta-analysis out of China was conducted evaluating 14 other studies that went through a rigorous review for terms of inclusion in the study. The literature review from which the reports were gleaned included studies published between 1986-2012 addressing a population of over 325,000 people, including over 4,000 cases and over 320,000 controls.

An increased risk of bladder cancer

The findings concluded that there was a 22% increased risk of bladder cancer for lifetime secondhand smoke exposure in nonsmoking patients compared with a nonsmoking population who was not subject to secondhand smoke exposure.1 A second meta-analysis was carried out to evaluate childhood exposure to secondhand smoke and the risk of bladder cancer. An even higher rate of increased risk of 43% was identified, but there were some potential bias issues in some of the prior evaluations.1 So, although it appears that exposure to secondhand smoke during childhood creates a statistically significant higher risk for bladder cancer, the statistical results may not reliable and require further evaluation.1

What does this mean?

The smoking population has a four-fold risk of bladder cancer compared with nonsmokers. We know that tobacco contains over 60 kinds of carcinogens that are typically cleaned from the body through the blood and urinary tract. The study findings suggest that secondhand smoke may also contain the same carcinogens, and which activate the disease development pathways. Additional basic experiments should be carried out in order to confirm the role of secondhand smoke in the formation of bladder cancer.

This comprehensive meta-analysis indicated a statistically significant increased risk of bladder cancer for lifetime secondhand smoke exposure. Further research should be conducted to confirm the association and to identify and clarify the biological mechanisms that may be responsible.1

  1. Yan, H., Ying, Y., Xie, H., Li, J., Wang, X., He, L., … Zheng, X. (2018). Secondhand smoking increases bladder cancer risk in nonsmoking population: a meta-analysis. Cancer management and research, 10, 3781–3791. doi:10.2147/CMAR.S175062


  • ayesha7
    4 months ago

    As with others, I grew up when everyone smoked including my mother and father. Now after 30 years in the operating room working at the sterile field and breathing the smoke plumbs from the electro cautery I also have bladder cancer for many years. It came from the smoke i breathed everyday at work. The medical field will never admit to it.

  • Sarah Wallin moderator
    4 months ago

    @ayesha7, Thank you for sharing with us. It sounds like you can relate with many others who’ve commented here. Hopefully medical research may one day be able to show how exposure to secondhand smoke could possibly lead to this cancer. Take care, Sarah ( Team Member)

  • RB36
    4 months ago

    Born in ’44, when I grew up about everyone smoked, I never did, but I was probably near 40 when I got away from it. No way to know, but I guess I support the facts.

  • Sarah Wallin moderator
    4 months ago

    @rb36, I hope they continue researching this topic to learn more about the risks of long term exposure to secondhand smoke. Thanks for sharing with us. -Sarah ( Team Member)

  • DiaB
    4 months ago

    I grew up in a heavy second hand smoke environment. I believe it contributed to my bladder cancer.

  • Alina Ahsan moderator
    4 months ago

    @diab With this research, I think healthcare professionals should definitely ask about exposure to secondhand smoke and consider it as a risk factor for developing bladder cancer. Thanks for reading and taking the time to tell us about your experience.
    -Alina, Team Member

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