Monday, November 19, 2007

2007 - Medical Cannabis in Oncology

"Medical Cannabis in Oncology"

I came across this article while I was searching on PubMed on the Brown University Library Website. It was published in the European Journal of Cancer on September 19, 2007. The content of this article has a great impact on the public perception of this technology. The use of medical marijuana (cannabis) for medical and social purposes has been debated for years. While interest in marijuana in the 1980s and 1990s focused on preventing its recreational use, attention is now being turned to its clinical and medicinal uses.

Patients and doctors have resorted to medical marijuana when conventional treatments were unsuccessful or deficient for the past four thousand years. Nonetheless, the safety and efficacy of cannabis remains controversial. The U.S. Food and Drug Administration (FDA) does not support the use of smoked marijuana for medical purposes on the ground that no sound scientific studies, animal, or human data support its safety or efficacy. However, a growing number of U.S. states have passed legislation making medical cannabis available upon doctor’s recommendations. Medical marijuana can be used to treat refractory neurological symptoms, pain associated with multiple sclerosis (MS) or spinal cord injury, chronic neuralgic pain, aids-related anorexia, HIV medication induced nausea and vomiting, Crohn’s disease, and Tourette syndrome. Other palliative effects include insomnia relief, mood elevation, appetite stimulation, and analgesia.

Cancer is the second leading cause of death in the United States, and one of the top ten leading causes of death in the world. Beneficial effects of marijuana have been reported for cancer-associated anorexia, delayed chemo or radiotherapy induced nausea, and vomiting. If there is a reason to approve the use of marijuana for medicinal purposes, in the public’s eye, there is not one better than for the treatment of cancer.

Much of the existing controversy surrounding the positive effects of medicinal marijuana is due to the lack of well-designed (randomized, double-blind, and placebo-controlled) and adequately powered clinical trials. The majority of clinical trials done so far have evaluated a wide range of different cannabis products, varying in dose, cannabinoid content, quality, and route of administration, in a heterogeneous patient population. Hence, the existing clinical data is inappropriate for comparison, thus making it unable to draw sound scientific conclusions.

One explanation the article gives for the lack of clinical trials is the fact that the current legal status of medicinal marijuana differs around the world and within the nation. In most countries, medicinal cannabis is illegal. As a result, registered standardized products are limited or unavailable. In the US, there are only two FDA-approved medicinal cannabis products available, Marinol and Cesamet. The Investigative New Drug Application of a third medicinal cannabis product, Sativex, was accepted in April 2006.

In the Netherlands, however, the policy surrounding the medicinal use of marijuana is quite disparate from that in the United States. Since September 2003, a legal medicinal cannabis product, constituting the whole range of cannabinoids and meeting pharmaceutical quality standards, has been available for pre-clinical and clinical research, drug formulation development, and on prescription for patients. This change in policy was expected to cause major changes leading to the general acceptance of marijuana for medicinal purposes, especially in treating cancer. However, four years of clinical experience with legal, standardized medicinal cannabis in the Netherlands has not led to the desired results.

A gap between the medicinal marijuana proponents and opponents still exists. Contrary to what was expected, only a minority of patients resorts to physician prescribed cannabis distributed by their community pharmacy. Preclinical research with crude cannabis varieties is ongoing in the Netherlands, but far fewer than expected. The Dutch Minister of Public Health, who was responsible for the initiated policy, decided to guarantee continued distribution and availability of legal medicinal cannabis until the end of 2007, but a renewed decision to keep medicinal marijuana legal in the Netherlands will depend on registration of the only one drug derived from cannabis varieties in the Netherlands. Thus, while many proponents of medical marijuana viewed the Netherlands as the leader in changes to medical marijuana policies, the efforts to make marijuana accepted in the medical community in Netherlands have been unsuccessful.

The percent of cancer patients that use legal cannabis fluctuates between 8% and 23%. According to the article, cancer-associated use of medicinal marijuana seems to be especially low. The majority of patients still acquire medicinal cannabis through illegal distributors, “coffee-shops”, or by growing at home despite its legalization. Thus, firm scientific evidence has not been found and the controversy around medicinal marijuana still carries on.


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