Cannabis flowers have been used as a medicine for as long as humans have been aware they exist. I will attempt to stay on topic with this. I'll save the rant about the grave injustice to humanity that is cannabis prohibition for another post.
Virtual everyone is aware that the effects of a number cannabinoids found in the cannabis plant are beneficial to patients undergoing chemotherapy. The primary reasons cited for this by physicians are the antiemetic and appetite stimulation effects, (aka "the munchies") but patient's themselves tend to offer more diverse reasoning. This is quickly becoming the generally accepted medical consensus.
Ask this question on some parts of the internet and you'll get a resounding and emphatic yes, complete with a TL:DR wall of text blasting pharmaceutical companies and modern medicine for creating perpetual patients and not healing anyone. Ask the very same question on another part of the internet and you'll get a tempered no, complete with an additional paragraph attesting full appeal to the current mainstream medical opinion and repeated use of the word "evidence." So, which is it? In my limited experience with how the conflicting sides engage each other on this issue: the yes crowd will provide links to studies that conclude the compounds in cannabis destroy cancer cells in vitro, as well as patient testimonials involving people stating they were able to cure their cancer with cannabis oil. The no crowd will label all of this a severe affront to the scientific method, and then simply state in vitro studies usually do not provide the same results in vivo. The argument usually ends, each person considering the other a fool. Neither side bothering to get too in depth. To answer the question posed above, I don't know for sure whether or not cannabis outright cures all cancer. I would agree that it is beneficial to most cancer patients, and even that it potentially can cure cancer. Here is well documented case involving an infant with an inoperable brain tumor ( Giloma) that was cured with cannabis oil. I like this case in particular because the patient did not have any additional treatments that may have interfered with the results. I linked a study that seems to demonstrate a mechanism of action below as well.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2673842/
http://www.huffingtonpost.com/2012/12/01/cannabis-for-infants-brai_n_2224898.html
This is one of the only cases I can find where the patient did not receive any additional treatment and one of the hundreds of studies I've read that actually seems to apply to a real life situation. As I stated above, I don't know for sure whether or not cannabis outright cures all cancer. I am however willing to bet that in the future cannabis extracts will be a cornerstone of treatment for all cancer.
