During the annual meeting of the American Urological Association, Dr. Anil Thomas found with his team of researchers at Kaiser Permanente Los Angeles Medical Center that cannabis smokers were 45% less likely to be diagnosed with bladder cancer than patients who did not smoke at all. While Dr. Thomas also made sure to emphasize that the study did not prove that marijuana smoking prevents bladder cancer, the research leads the way for others to replicate.

Source: https://www.medscape.com/viewarticle/803983