Marijuana use was not associated with bladder cancer recurrence in a large prospective study
Among 1,472 bladder cancer patients, marijuana use (24.7%) was not associated with cancer recurrence or progression, while tobacco smoking duration and pack-years significantly increased recurrence risk.
Quick Facts
What This Study Found
Longer cigarette smoking duration and more pack-years were associated with higher recurrence risk in a dose-dependent manner (40+ years: HR 2.36; 40+ pack-years: HR 1.97). No associations were found for marijuana, e-cigarettes, pipes, or cigars with bladder cancer recurrence or progression.
Key Numbers
1,472 patients. 363 (24.7%) used marijuana. 59.4% former smokers. 7.5% current smokers. Marijuana: no association with recurrence or progression. Tobacco 40+ years: HR 2.36 (95% CI 1.43-3.91). 40+ pack-years: HR 1.97 (95% CI 1.32-2.95).
How They Did This
Prospective Be-Well Study of 1,472 patients with non-muscle-invasive bladder cancer (NMIBC) diagnosed 2015-2019 in Kaiser Permanente California. Baseline interviews on tobacco, e-cigarette, and marijuana use. Cox regression estimated hazard ratios for recurrence and progression.
Why This Research Matters
With nearly a quarter of bladder cancer patients reporting marijuana use, the absence of a recurrence association is reassuring for patients and clinicians, especially in contrast to the strong tobacco-recurrence link.
The Bigger Picture
This adds to the growing evidence that marijuana and tobacco have distinctly different cancer risk profiles, consistent with reviews suggesting marijuana does not appear to cause lung cancer either.
What This Study Doesn't Tell Us
Self-reported substance use at a single time point. Marijuana use details (frequency, amount, duration) not fully captured. Relatively short follow-up (26.4 months). NMIBC-specific findings may not apply to other cancers.
Questions This Raises
- ?Would longer follow-up reveal marijuana associations?
- ?Does the route of marijuana administration (smoking vs. edibles) matter for cancer outcomes?
Trust & Context
- Key Stat:
- Marijuana: no recurrence link. Tobacco 40+ years: 2.4x recurrence risk.
- Evidence Grade:
- Large prospective cohort in an integrated healthcare system with clinical outcomes, published in JAMA Network Open.
- Study Age:
- Published in 2022, patients diagnosed 2015-2019.
- Original Title:
- Smoking Behaviors and Prognosis in Patients With Non-Muscle-Invasive Bladder Cancer in the Be-Well Study.
- Published In:
- JAMA network open, 5(11), e2244430 (2022)
- Authors:
- Kwan, Marilyn L, Haque, Reina, Young-Wolff, Kelly C(42), Lee, Valerie S, Roh, Janise M, Ergas, Isaac J, Wang, Zinian, Cannavale, Kimberly L, Ambrosone, Christine B, Loo, Ronald K, Aaronson, David S, Quesenberry, Charles P, Kushi, Lawrence H, Tang, Li
- Database ID:
- RTHC-03986
Evidence Hierarchy
Enrolls participants and follows them forward in time.
What do these levels mean? →Frequently Asked Questions
Does marijuana affect bladder cancer outcomes?
In this study of 1,472 bladder cancer patients, marijuana use (reported by 25%) was not associated with cancer recurrence or progression, unlike tobacco smoking which significantly increased risk.
Is marijuana safer than tobacco for cancer patients?
This study found no cancer recurrence association with marijuana, e-cigarettes, pipes, or cigars, while tobacco cigarette smoking duration and pack-years strongly predicted bladder cancer recurrence in a dose-dependent pattern.
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Cite This Study
https://rethinkthc.com/research/RTHC-03986APA
Kwan, Marilyn L; Haque, Reina; Young-Wolff, Kelly C; Lee, Valerie S; Roh, Janise M; Ergas, Isaac J; Wang, Zinian; Cannavale, Kimberly L; Ambrosone, Christine B; Loo, Ronald K; Aaronson, David S; Quesenberry, Charles P; Kushi, Lawrence H; Tang, Li. (2022). Smoking Behaviors and Prognosis in Patients With Non-Muscle-Invasive Bladder Cancer in the Be-Well Study.. JAMA network open, 5(11), e2244430. https://doi.org/10.1001/jamanetworkopen.2022.44430
MLA
Kwan, Marilyn L, et al. "Smoking Behaviors and Prognosis in Patients With Non-Muscle-Invasive Bladder Cancer in the Be-Well Study.." JAMA network open, 2022. https://doi.org/10.1001/jamanetworkopen.2022.44430
RethinkTHC
RethinkTHC Research Database. "Smoking Behaviors and Prognosis in Patients With Non-Muscle-..." RTHC-03986. Retrieved from https://rethinkthc.com/research/kwan-2022-smoking-behaviors-and-prognosis
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.