A new study suggests that researchers should take a closer look at cannabis as a treatment for cancer and its symptoms. The team behind the study says the results suggest the federal government should remove restrictions on that research.

An organization called Cancer Playbook, which is based in Evergreen, paid for the study. Cancer Playbook’s head of research says it works to provide people battling cancer with information about what treatments have helped other cancer patients – and that often includes medical marijuana.

The study reviewed more than 10,000 published papers on medical cannabis. That makes it the most comprehensive analysis ever conducted on the topic, according to a recent story in The Guardian.

Ryan Castle is the director of research for Cancer Playbook and he led the study. It found that cannabis showed clear promise in many aspects of cancer treatment, from reducing pain to shrinking tumors.

Ryan talked with Erin O’Toole about study and why it’s hard to get reliable data on the effectiveness of medical marijuana – which is legal in Colorado and many other states, but still illegal at the federal level.