I wrote a very in depth paper about legalizing marijuana (pros and cons) and covered this aspect of it. I had to cite empirical articles and peer-reviewed articles as well as other scholarly sources and I am figuring you have a somewhat similar requirement.

Details:
Marijuana is used to ease the symptoms associated with Chemotherapy. The last time I checked (and this may have changed so please verify) the use of medical marijuana is legal in 14 states.
Physicians have long-since stated that the use of marijuana eases different types of pain, nausea, vomiting, and other types of symptoms and is used to treat these symptoms in people who have multiple sclerosis, cancer, and AIDS. Marijuana is considerably less toxic than many of the other drugs that physicians give patients to try to help these symptoms (Sibbald, 2005).
It also helps in situations where patients have significant decreases in appetite, spastic disorders, and has been known to successfully help with some disorders to to it’s anti-inflammatory effects.
References (in APA style)
Gerber, R. (2004). Legalizing Marijuana: Drug policy Reform and Prohibition Politics. New York: Praeger Publishing.
Neuville, T. (2007). Medical dope. Retrieved May 12, 2007, from Shakopee Valley News Web site: http://www.shakopeenews.com/node/2297.
Sibbald, B. (2005, August 30). New medicinal marijuana rules ease onus on physicians. Medical Association Journal, Vol. 173 (Issue 5), 473-473.