Today you can find marijuana everywhere, dispensaries around every corner or easily accessible through social media. This normalization is leading researchers to investigate its effects on various health conditions and the dangers associated with overconsumption of marijuana. This research shows that there is an association between marijuana use and the weakening of our immune system. Its consumption affects key parts of our defenses against cancer while contributing to faster tumor progression, particularly for gastrointestinal conditions. In general, individuals with substance use disorders, including cannabis use disorder (CUD), are more likely to experience delays in diagnosis and reduced involvement in their medical care. In addition, behavioral and psychiatric conditions linked to marijuana use such as anxiety and depression may prevent the adherence to the required treatment leading to negative prognosis.

Two recent studies, one on chronic pancreatitis and the other on colorectal cancer, highlight how CUD is linked to poorer outcomes in individuals suffering from chronic pancreatitis and colorectal cancer.

In the first study, researchers analyzed over 1,000 patients and found that those with pre-existing CUD were more likely to die within 5 years of receiving a colon cancer diagnosis. Among those who had a documented history of CUD prior to being diagnosed, the difference in outcomes were stark:

  • Five-year mortality rate:
    • Patients with CUD:55.9%
    • Patients without CUD: 5.1%

In the second study, researchers linked CUD to worsened clinical outcomes in individuals with chronic pancreatitis, a painful and progressive condition where the pancreas becomes inflamed and damaged over time. These patients were found to be at greater risk of pancreatic flare up, pancreatic cancer, all-cause mortality, and pancreatic necrosis.

This association held firm even after the researchers accounted for opioid use, suggesting that marijuana itself may contribute to disease progression and complications.

CUD affects 3 in 10 users in the U.S., according to the CDC. As it becomes more normalized, the risks for vulnerable populations, in this case those with colon cancer and pancreatitis, continue to grow. These risks are too significant and call for more research, awareness and education, serving as a critical reminder that marijuana use is not harmless, especially when dependence develops.

References:

Centers for Disease Control and Prevention. (2024). Cannabis use disorder. https://www.cdc.gov/cannabis/health-effects/cannabis-use-disorder.html

Brooks, A. (2025). Cannabis use, dependence linked to worse clinical outcomes in chronic pancreatitis. HCPLive. https://www.hcplive.com/view/cannabis-use-dependence-linked-worse-clinical-outcomes-chronic-pancreatitis

The ASCO Post Staff. (2025). Cannabis use disorder significantly increases mortality risk in colorectal cancer. The ASCO Post. https://ascopost.com/news/may-2025/cannabis-use-disorder-significantly-increases-mortality-risk-in-colorectal-cancer/

Cuomo, R. (2025). Cannabis use disorder and mortality among patients with colon cancer. Annals of Epidemiology, 35(4), 140-147. https://doi.org/10.1016/j.annepidem.2025.04.012