“Background: Cannabis use is increasing, including among smokers, an at-risk population for cancer. Research is equivocal on whether using cannabis inhibits quitting cigarettes. The current longitudinal study investigated associations between smoking cannabis and subsequently quitting cigarettes.

Results: Adjusted cigarette quitting rates at follow-up did not differ significantly by baseline cannabis smoking status [never 36.2%, 95% confidence interval (CI), 34.5%-37.8%; former 34.1%, CI, 31.4%-37.0%; recent 33.6%, CI, 30.1%-37.3%], nor by frequency of cannabis smoking (low 31.4%, CI, 25.6%-37.3%; moderate 36.7%, CI, 30.7%-42.3%; high 34.4%, CI, 28.3%-40.2%) among recent baseline cannabis smokers. In cross-sectional analyses conducted at follow-up the proportion of cigarette smokers intending to quit smoking cigarettes in the next 30 days did not differ by cannabis smoking status (p=0.83).

Conclusions: Results do not support the hypothesis that cannabis smoking inhibits quitting cigarette smoking among adults.”

https://pubmed.ncbi.nlm.nih.gov/34348959/

“Results do not support the hypothesis that cannabis smoking inhibits quitting cigarette smoking among adults.” https://cebp.aacrjournals.org/content/early/2021/08/04/1055-9965.EPI-20-1810