Researchers at the University of California San Diego School of Medicine have found that individuals with colon cancer and a documented history of high cannabis use were more than 20 times more likely to die within five years of diagnosis compared to those without such a history.
“This study adds to a growing body of evidence suggesting that heavy cannabis use may have underrecognized impacts on the immune system, mental health and treatment behaviors — all of which could influence cancer outcomes,” said lead author Raphael Cuomo, Ph.D., associate professor in the Department of Anesthesiology at UC San Diego School of Medicine.
The research team drew on electronic health records from more than 1,000 colon cancer patients treated across the University of California Health system between 2012 and 2024. They evaluated how cancer outcomes differed based on patients’ documented cannabis use before diagnosis, controlling for age, sex and indicators of disease severity such as tumor staging and cancer biomarkers.
The analysis found:
Patients with a history of cannabis use disorder (CUD) had a substantially higher five-year mortality rate (55.88 %) compared to patients without CUD (5.05 %).
Patients diagnosed with CUD prior to cancer diagnosis were 24.4 times more likely to die within five years of diagnosis compared to those without CUD.
While some laboratory studies have shown anti-tumor effects from certain cannabis compounds, the authors note that real-world use is more complex. Given the increasing prevalence and social acceptance of cannabis use, they also emphasize the need to further investigate its long-term effects in medically vulnerable populations.
“High cannabis use is often associated with depression, anxiety and other challenges that may compromise a patient’s ability to engage fully with cancer treatment,” said Cuomo, who is also a member of UC San Diego Moore’s Cancer Center. “However, this isn’t about vilifying cannabis. It’s about understanding the full range of its impacts, especially for people facing serious illnesses. We hope these findings encourage more research — and more nuanced conversations — about how cannabis interacts with cancer biology and care.”
The study was published online in the Annals of Epidemiology. No funding or conflicts of interest were reported for this study.
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Journal
Annals of Epidemiology
DOI
10.1016/j.annepidem.2025.04.012
Media Contact
Miles Martin
University of California – San Diego
Journal
Annals of Epidemiology
DOI
10.1016/j.annepidem.2025.04.012
Journal
Annals of Epidemiology
DOI
10.1016/j.annepidem.2025.04.012
Keywords
/Life sciences/Plant sciences/Plants/Cannabis
/Health and medicine/Diseases and disorders/Cancer/Colon cancer
/Scientific community/Research programs/Cancer research
bu içeriği en az 2000 kelime olacak şekilde ve alt başlıklar ve madde içermiyecek şekilde ünlü bir science magazine için İngilizce olarak yeniden yaz. Teknik açıklamalar içersin ve viral olacak şekilde İngilizce yaz. Haber dışında başka bir şey içermesin. Haber içerisinde en az 12 paragraf ve her bir paragrafta da en az 50 kelime olsun. Cevapta sadece haber olsun. Ayrıca haberi yazdıktan sonra içerikten yararlanarak aşağıdaki başlıkların bilgisi var ise haberin altında doldur. Eğer yoksa bilgisi ilgili kısmı yazma.:
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Tags: cancer mortality rates and cannabiscancer treatment behaviors and cannabiscannabis use and cancer survivalcannabis use and colon cancercannabis use disorder impactcolon cancer patient outcomescolon cancer research findingsElectronic health records researchhigh cannabis consumption mortalityimmune system effects of cannabismental health and cancer treatmentUniversity of California San Diego study
