Post-diagnosis cannabis use and its association with health status and quality of life in cancer survivors.
Kasiri N, McDaniels-Davidson C, et al. • Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer • 2026
Cancer survivors reporting average or below average mental health had significantly higher odds of post-diagnosis cannabis use, while associations with physical health and quality of life were positive but not statistically significant.
Key Findings
Results
Cancer survivors with average or below average mental health had significantly higher odds of post-diagnosis cannabis use compared to those with above average mental health.
Adjusted OR = 1.88 (95% CI = 1.13–3.11) for average or below average mental health and post-diagnosis cannabis use
Survey-weighted logistic regression was used to estimate adjusted odds ratios
'Above Average' mental health was the referent category
Most respondents (67.2%) reported above average mental health status
Results
The association between average or below average physical health and post-diagnosis cannabis use was positive but not statistically significant.
Adjusted OR = 1.38 (95% CI = 0.85–2.24) for physical health
Almost half of respondents (47.1%) reported above average physical health
The confidence interval crossed 1.0, indicating non-significance
Results
The association between average or below average quality of life and post-diagnosis cannabis use was positive but not statistically significant.
Adjusted OR = 1.24 (95% CI = 0.75–2.05) for quality of life
Most respondents (64.2%) reported above average quality of life
QoL was assessed using a single survey item with response options ranging from poor to excellent
Results
The associations between health status or quality of life and post-diagnosis cannabis use did not significantly differ by cancer stage, treatment status, or pre-diagnosis cannabis use.
Effect modification by cancer stage, treatment status, and pre-diagnosis cannabis use was explored using survey-weighted logistic regression
No statistically significant interaction was detected for any of the three subgroup variables
Pre-diagnosis cannabis use was considered as a potential modifier
Methods
The study sample included 652 cancer survivors recruited from an NCI-designated cancer center who responded to a 2022 online survey.
5,901 individuals who received care from 2018 to 2019 were invited; 954 responded and 652 were included in the analysis
The sample was weighted to represent the cancer center patient population
The weighted sample was 58.6% non-Hispanic White, 58.5% female, and 51.8% aged 65 years or older
Post-diagnosis cannabis use was self-reported as 'Yes' or 'No'
What This Means
This research suggests that cancer survivors who rate their mental health as average or below average are nearly twice as likely to report using cannabis after their cancer diagnosis compared to those who rate their mental health as above average. The study surveyed 652 people who had been treated at a major cancer center, asking them about their cannabis use since diagnosis and how they would rate their physical health, mental health, and overall quality of life. While poorer physical health and lower quality of life were also associated with higher cannabis use, those associations were not statistically significant, meaning they could plausibly be due to chance.
The study found that these patterns held regardless of whether the cancer was at an early or advanced stage, whether the person was still in active treatment, or whether they had used cannabis before their diagnosis. This consistency across different subgroups suggests the relationship between mental health and cannabis use after a cancer diagnosis is relatively broad rather than limited to specific circumstances.
This research matters because it highlights that mental health may be an important factor driving cannabis use among cancer survivors, a population that is increasingly using cannabis to manage symptoms and side effects. Understanding who is most likely to use cannabis—and why—can help healthcare providers have more informed conversations with their patients about cannabis use in the context of cancer care. The study is limited by its cross-sectional design and self-reported measures, meaning it cannot establish whether poor mental health leads to cannabis use, or vice versa.
Kasiri N, McDaniels-Davidson C, Doran N, Patel S, Strong D, Parada H. (2026). Post-diagnosis cannabis use and its association with health status and quality of life in cancer survivors.. Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer. https://doi.org/10.1007/s00520-026-11185-w