Cannabis use associated with inferior immunotherapy outcomes OR confounding bias?

Discussions among healthcare professionals ignited on Twitter/X over the following post by Ishwaria Subbiah, the Executive Director of Cancer Care Equity and Professional Wellness at Sarah Cannon Research Institute, where she shared a study about immunotherapy outcomes on cannabis use:

“Cannabis use associated with inferior immunotherapy outcomes

• Median time to tumor progression 3.4m (95% CI, 1.8–6.0) for cannabis users vs 13.1m (95% CI, 6.0–NA, p 0.0025) for nonusers
• Prospective study from 2020 of pts w adv cancers receiving immune checkpoint inhibitors
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7563978/“

Quoted below are some of the responses on this topic:

“Interesting data… natural products used during cancer therapy can IN THEORY be additive, synergistic, or ANTAGONISTIC… It’s why preclinical models and prospective studies are paramount to understand these effects. We need to understand the potential Good-Bad and the Ugly” – Rod Rocconi, the Director of Cancer Center and Research Institute at the University of Mississippi Medical Center.

“Interesting. Make you think whether cannabis use with immunotherapy in cancer maybe a bad idea. You can not conclude but it does make you wonder.” – Naoto T Ueno, the Director of the University of Hawaiʻi Cancer Center.

“Let us all pledge to NOT use this heavily confounded/flawed/implausible study to guilt our patients who use cannabis to help cope with the symptom burden of cancer/its treatments. That dramatic separation of curves is crazy. Cannabis use likely a proxy for other things here.” – Manni Mohyuddin, Assistant Professor Huntsman Cancer Institute, University of Utah.

“Cancer patients, if you want to use marijuana go for it (preferably don’t smoke it) and please do not guilt yourself into thinking it will suppress your immune system from fighting the cancer. If your quality of life is better on it then I see no issues.” – Aaron Goodman, hematologist/oncologist and an Associate Professor of Medicine at the University of California, San Diego. 

For the original post by Ishwaria Subbiah on Twitter/X click here.
For the article click here.