1. + Marijuana Kills Cancer Madeline McFarland Justin Moore Caitlyn Cassimatis Karolina Pogorzelski

2. + The Claim Marijuana kills cancer “National Cancer Institute finally admits marijuana kills cancer” Cannabinoids reduce tumor growth by causing apoptosis, blocking cell growth, and blocking the development of blood vessels necessary for tumor growth Cannabinoids may protect against inflammation of the colon and may have potential in reducing the risk of colon cancer, and possibly in its treatment A Men’s Health Study proves that cannabis can potentially kill cancer

3. + The Original Study

4. + Purpose & Hypothesis Type of Study: Observational/Correlational study using a multiethnic cohort of men in 2002 and 2003 Purpose: To see if cannabis and tobacco use altered the incidence of bladder cancer Hypothesis: Cannabis use will result in a decreased incidence of bladder cancer among subjects

5. + Methods 84,170 men aged 45 – 69 Data collected by mailed questionnaires Asked men about their drug use: cannabis only, tobacco only, both tobacco and cannabis, or neither substance Overall study contained 60, 703 men who used either substance and 23, 467 men who used neither Divided up into two age groups (45-54 yrs. old & 55-69 yrs. old) and based on the # of times of cannabis use: 1-2 times, 3-10 times, 11-99 times, 100-499 times, >500 times, & no frequency of use Followed for up to 11 years

6. + Results Association between cannabis use and risk of bladder cancer 279 men (0.3%) developed bladder cancer Of those men, 89 cannabis users (0.3%) and 190 non- cannabis users (0.4%) developed the cancer Tobacco use alone increased likelihood of bladder cancer by 1.5 times Risk of bladder cancer increased with joint use of tobacco and cannabis by 1.28 times Overall, results varied depending on the # of times of use of the substances Only statistical significance reached was for those who used cannabis 3-10 times; this was only 22% of the men who used cannabis

7. + Conclusion Inverse association between cannabis use and the incidence of bladder cancer 45% reduction in bladder cancer incidence with the use of cannabis Claimed further research needed to validate the results and prove that there is an actual biological effect of cannabis on incidence of bladder cancer “Cause and effect relationship has not been established”

8. + Problems With the Study Mailed questionnaires (self-reporting) Only surveyed men who had the Southern and Northern California Kaiser Permanente health plan Predominantly older, white men Did not account for other lifestyle factors (environment, occupation, etc.) The only statistical significance reached was when using cannabis 3-10 times (22% of all cannabis users) Did not assess time course b/w cannabis use and association of bladder cancer incidence

9. + Is the Media Article Believable? NORML (National Organization for the Reform of Marijuana Law) The Cancer Institute never claimed that marijuana kills cancer (no where on their site) Statistical significance not always reached in study State “few studies have been done on humans so too soon to judge the effects of cannabis” Other studies have proven the opposite: US Latin American Head and Neck Cancer Epidemiology Consortium Elevated risk of lung, mouth, tongue cancer