There is not much scientific evidence to support it. It would need to be tested properly in clinical trials to prove that it’s useful first! There are many other much better treatments that have been proven to treat cancer. Cannabis has many bad effects on you, especially on your brain. Taking cannabis can permanently and irreversibly alter your the chemistry inside your brain, and has been linked to lower intelligence and memory issues later in life. So you’re best off sticking to the legitimate cancer drugs!