Ah, and the mythology of cannabis grows.
There is no proof that cannabis does anything curative, but plenty of proof that it is harmful. There is, furthermore, reason to think that marijuana is a carcinogen.
All of the scientific evidence doesn't matter: with marijuana, the push is for use based on anecdotal rumors. That's not the way drugs should be included in the pharmacopeia!
BTW, there is a marijuana oil (THC) extract that is prescribed and sold. It is, of course, packaged, quality checked, and sold by pharmaceutical companies.
You need to do a lot more research on Cannabis oil. I am pleased to say that my state of Georgia has just passed legislation that will go into effect in 30-60 days which allows doctors to prescribe Cannabis oil for 8 specific conditions including cancer. Cannabis oil is having very positive results especially in brain cancer and lung cancer.
Prior to l937 Cannabis oil was used in many common medicines in the US and it worked.