could imagine that cannabis might one day offer hope as a cure for
cancer? The United States government, that's who.
the past 30 years, U.S. officials have willfully ignored clinical
research indicating that marijuana can inhibit the growth of certain
type of malignant tumors. However, the recent publication of a trio
of clinical studies and a pair of scientific reviews have effectively
blown the lid off "Cancergate," and revealed that pot's
medical value may be far greater than ever presumed.
year, five scientific journals published prominent articles trumpeting
cannabinoids (compounds in marijuana) as potential anti-cancer agents.
trial data published in January 2003 issue of the Journal
of the American Society of Clinical Investigation that found
cannabinoids significantly inhibit skin tumor growth in mice.
Investigators of the study concluded, "The present data
indicate that local cannabinoids administration may constitute
an alternative therapeutic approach for the treatment of non-melanoma
trial data published in the March 2003 issue of The FASEB
Journal that found that the "local administration of
a non-psychoactive cannabinoid inhibits angiogenesis (tissue
growth) of malignant gliomas (brain tumors)."
- A clinical
review in the October 2003 issue of the prestigious journal
Nature Reviews Cancer that concluded that cannabinoids'
"favorable drug safety profile" and proven ability
to inhibit tumor growth make them desirable agents in the treatment
of cancer. According to the review's author, tumors inhibited
by cannabinoids include: lung carcinoma, glioma, thyroid epithelioma,
lymphoma/leukemia, skin carcinoma, uterus carcinoma, breast
carcinoma, prostate carcinoma, and neuroblastoma (a malignant
tumor originating in the autonomic nervous system or the adrenal
medulla and occurring chiefly in infants and young children).
trial data published in the November 2003 issue of the Journal
of Pharmacology and Experimental Therapeutics that found
the administration of the cannabinoid cannabidiol (CBD) inhibits
the growth of human glioma cells both in vitro (e.g., a petri
dish) and in animals in a dose-dependent manner. Investigators
concluded, "Non-psychoactive CBD produce[s] a significant
antitumor activity both in vitro and in vivo, thus suggesting
a possible application of CBD as an antineoplastic agent (something
which prevents the growth of malignant cells.)"
- And finally,
a clinical review in the December 2003 issue of the journal
Expert Opinion on Therapeutic Targets that summarized
"the demonstrated antitumor actions of cannabinoids,"
and elaborated on "possible avenues for the future development
of cannabinoids as antitumor agents."
SUBSEQUENT MEDIA BLACKOUT
these stunning findings, media coverage of them in North America
has been virtually non-existent. As noted by Richard Cowan, editor
of the website MarijuanaNews.com, "The New York Times,
The Washington Post and Los Angeles Times all ignored
this story, even though its newsworthiness is indisputable: a benign
substance occurring in nature destroys deadly brain tumors."
the media blackout? For starters, all of these studies were conducted
overseas. And secondly, not one of them has been acknowledged by
the U.S. government.
KNEW IN '74… AND AGAIN IN '96!
wasn't always the case. In fact, the first ever experiment documenting
pot's anti-tumor effects took place in 1974 at the Medical College
of Virginia at the behest of the U.S. government. The results of
that study, immortalized in an August 18, 1974 Washington Post
newspaper feature, were that "THC slowed the growth of lung
cancers, breast cancers and a virus-induced leukemia in laboratory
mice, and prolonged their lives by as much as 36 percent."
these favorable preliminary findings, U.S. government officials
banished the study, and refused to fund any follow up research until
conducting a similar – though secret – study in the mid-1990s.
That study, conducted by the U.S. National Toxicology Program to
the tune of $2 million concluded that mice and rats administered
high doses of THC over long periods had greater protection against
malignant tumors than untreated controls. However, rather than publicize
their findings, government researchers shelved the results –
which only became public one year later after a draft copy of its
findings were leaked in 1997 to the journal AIDS Treatment News,
which in turn forwarded the story to the national media.
in the nearly eight years since the completion of the National Toxicology
trial, the U.S. government has yet to fund a single additional study
examining pot's potential as an anti-cancer agent.
IGNORED NO MORE
researchers at Madrid, Spain's Complutense University, School of
Biology have generously picked up where U.S. researchers so abruptly
left off. In 1998, the research team – led by investigator Manuel
Guzman – discovered that THC can selectively induce program cell
death in brain tumor cells without negatively impacting the surrounding
healthy cells. Then in 2000, Guzman's team reported in the journal
Nature Medicine that injections of synthetic THC eradicated malignant
gliomas (brain tumors) in one-third of treated rats, and prolonged
life in another third by six weeks. A commentary to the study noted
that the results were the first to convincingly demonstrate that
cannabis-based treatments may successfully combat cancer.
Guzman believes that enough favorable clinical evidence exists supporting
pot's anti-cancer properties to warrant clinical trials in humans.
"The scientific community has gained substantial knowledge
of the palliative and anti-tumor actions of cannabinoids during
the past few years," Guzman wrote in the October 2003 issue
of Nature Reviews Cancer. "Anti-tumor compounds should
selectively affect tumor cells [and] it seems that cannabinoids
can do this, as they kill [malignant] tumor cells but do not affect
their non-transformed counterparts and might even protect them from
cell death. … As cannabinoids are relatively safe compounds, it
would be desirable that clinical trials using cannabinoids … could
accompany [ongoing] laboratory studies to allow us to use these
compounds in the treatment of cancer." Guzman concludes the
article by noting that the Spanish Ministry of Health recently approved
a human clinical trial – the first ever – aimed at investigating
the effects of intracranially administered THC on the life expectancy
of volunteers suffering from malignant brain tumors.
research continues to show tremendous potential in the treatment
of cancer," summarizes University of Southern California professor
Mitch Earleywine, author of the book Understanding
Marijuana: A New Look at the Scientific Evidence. However,
he laments that the "vast majority of this work originates
outside the United States, often in countries that lack our economic
and scientific advantages. Let's hope that our drug policy won't
stymie the battle against the second leading cause of death in America."
Let's not add a potential treatment for cancer to the ever-growing
list of victims of pot prohibition.
Paul Armentano [send him mail]
is the senior policy analyst for the NORML Foundation
in Washington, DC.