42% of breast cancer patients used cannabis, most during active treatment, and few told their doctors
In a survey of 612 breast cancer patients, 42% used cannabis primarily for pain, insomnia, and anxiety, with 79% using it during active treatment and only 39% discussing it with any physician.
Quick Facts
What This Study Found
42% of breast cancer patients used cannabis for symptom relief (pain 78%, insomnia 70%, anxiety 57%). 49% of cannabis users believed it could treat cancer itself. 79% used cannabis during active treatment (systemic therapy, radiation, surgery). Only 39% discussed cannabis with any physician.
Key Numbers
612 participants, 257 (42%) used cannabis. Reasons: pain (78%), insomnia (70%), anxiety (57%), stress (51%), nausea/vomiting (46%). 49% believed cannabis could treat cancer. 79% used during treatment. Only 39% discussed with physicians.
How They Did This
Anonymous online survey of US-based Breastcancer.org and Healthline.com members with self-reported breast cancer diagnosis within 5 years (age 18+). 612 participants total, 257 cannabis users.
Why This Research Matters
The high rate of undisclosed cannabis use during active cancer treatment creates potential risks from drug interactions that neither patients nor their oncologists may be aware of.
The Bigger Picture
Nearly half of breast cancer patients using cannabis believe it can treat cancer, a misconception that combined with low physician disclosure rates creates a concerning information gap in oncology.
What This Study Doesn't Tell Us
Self-selected sample from advocacy websites may overrepresent cannabis-favorable attitudes. Self-reported cancer diagnosis. Online survey may underrepresent older or less internet-connected patients.
Questions This Raises
- ?Does cannabis use during chemotherapy affect treatment outcomes?
- ?Why are so few patients discussing cannabis with oncologists?
- ?Would oncologist-initiated conversations improve disclosure rates?
Trust & Context
- Key Stat:
- 79% used cannabis during active treatment; only 39% told their doctor
- Evidence Grade:
- Moderate: reasonable sample size with detailed survey, but self-selected from advocacy websites.
- Study Age:
- Published in 2022.
- Original Title:
- A Coala-T-Cannabis Survey Study of breast cancer patients' use of cannabis before, during, and after treatment.
- Published In:
- Cancer, 128(1), 160-168 (2022)
- Authors:
- Weiss, Marisa C, Hibbs, Julianne E, Buckley, Meghan E, Danese, Sherry R, Leitenberger, Adam, Bollmann-Jenkins, Melissa, Meske, Sam W, Aliano-Ruiz, Katherine E, McHugh, Theresa W, Larson, Sharon L, Le, Elaine H, Green, Nancye L, Gilman, Paul B, Kaklamani, Virginia G, Chlebowski, Rowan T, Martinez, Diana M
- Database ID:
- RTHC-04294
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Why do so few patients tell their doctors?
The study found patients were unaware of potential interactions, perceived cannabis as safe, and sought information from the internet and family/friends rather than healthcare providers.
Is it safe to use cannabis during cancer treatment?
Using cannabis during active treatment (chemotherapy, radiation, surgery) carries potential risks from drug interactions and unknown effects on treatment efficacy. The researchers emphasize the importance of physician-patient dialogue about cannabis use.
Do patients really believe cannabis treats cancer?
Yes. 49% of cannabis-using breast cancer patients believed medical cannabis could be used to treat cancer itself, not just manage symptoms. This belief is not supported by clinical evidence.
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Cite This Study
https://rethinkthc.com/research/RTHC-04294APA
Weiss, Marisa C; Hibbs, Julianne E; Buckley, Meghan E; Danese, Sherry R; Leitenberger, Adam; Bollmann-Jenkins, Melissa; Meske, Sam W; Aliano-Ruiz, Katherine E; McHugh, Theresa W; Larson, Sharon L; Le, Elaine H; Green, Nancye L; Gilman, Paul B; Kaklamani, Virginia G; Chlebowski, Rowan T; Martinez, Diana M. (2022). A Coala-T-Cannabis Survey Study of breast cancer patients' use of cannabis before, during, and after treatment.. Cancer, 128(1), 160-168. https://doi.org/10.1002/cncr.33906
MLA
Weiss, Marisa C, et al. "A Coala-T-Cannabis Survey Study of breast cancer patients' use of cannabis before, during, and after treatment.." Cancer, 2022. https://doi.org/10.1002/cncr.33906
RethinkTHC
RethinkTHC Research Database. "A Coala-T-Cannabis Survey Study of breast cancer patients' u..." RTHC-04294. Retrieved from https://rethinkthc.com/research/weiss-2022-a-coalatcannabis-survey-study
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.