While cannabis appears to have many potentially beneficial effects for patients with cancer, no actual parameters for successfully treating cancer with any type of cannabis have ever been determined with clinical science. Any recommendations (eg the commonly mentioned formula called Rick Simpson Oil) are based entirely on anecdote and the hope that observations in the laboratory might translate into clinical effects. The good news is that cannabis is remarkably non-toxic to human physiology, so whatever preparations are tried there is little reason to be concerned about doing harm (unlike many other 'folk-medicine' treatments advocated for cancer). Some of the scientifically recognized effects of cannabis such as reducing nausea, improving appetite, modifying mood, and promoting relaxation are enormously helpful for cancer patients and help fortify the desire to go on, something that HAS been clinically demonstrated to have a positive effect on cancer survival. And, of course, I strongly recommend continuing conventional medical evaluation and treatment along with any medicinal cannabis use.