COMMENTS: 18 The Marijuana
Cancer Cure Cult
Sign up to stay up to date on the
latest headlines via email.
In his 1971 State of the Union speech, President Richard
Nixon declared war on cancer, prompting passage of the
National Cancer Act, aimed at making the "conquest of
cancer a national crusade." Just four years later, scientists
from the National Cancer Institute published a study
demonstrating that a group
of compounds taken from a common, widely cultivated
plant shrank lung tumors that had been implanted in mice,
extending their survival.
In a world that made sense, this plant and the anticancer
drugs it produced would have been rushed into further
testing, and we'd have known in a few years whether they
had potential as treatments for human cancers. Instead,
research proceeded at a glacial pace, with almost no
further progress till the 1990s. Since then, vast quantities
of lab and animal data have confirmed those early findings,
but studies of these plant compounds in actual human
beings with cancer remain nearly nonexistent.
What got in the way was Nixon's other war, the "war on
drugs." The plant in question was cannabis sativa
-- marijuana -- public enemy number one in that other war,
and discovering that marijuana had beneficial properties
was the last thing the U.S. government wanted to do.
Dr. Manuel Guzman of Complutense University in Madrid,
lead author of the only human study yet published of a
cannabinoid as cancer treatment, puts it slightly more
diplomatically. The lack of immediate followup to those
early reports "remains a mystery to me," he says. Guzman
cites a number of obstacles to human trials, including the
fact that cannabinoids are "still seen by many doctors and
regulatory agencies as drugs of abuse," as well as "lots of
paperwork" and a lack of commercial interest in natural
compounds that can't be patented.
Complicating things further, the relative vacuum created
by the lack of human studies and the hostility of the U.S.
government to the whole question of marijuana's beneficial
effects has left the field wide open for zealots who promote
cannabis as a "cure" for cancer as if it were already a
proven fact rather than a possibility in desperate need of
serious study.
A Protective Effect?
Instead of researching cannabinoids as anticancer drugs,
federal officials have continued to falsely imply that
marijuana causes lung cancer. For example, a 2002
brochure for parents, "Talk to Your Child About Marijuana,"
still available on the Office of National Drug Control Policy
Web site, advises, "Smoking marijuana is as least as bad as
smoking cigarettes."
In fact, the largest, most well-controlled studies have
consistently failed to find an increased risk of lung cancer or
other typically tobacco-related cancers among marijuana
smokers. These include a 65,000-patient 1997 study
conducted at Kaiser Permanente in Oakland, California and
a 2006 case-control study (in which patients with cancer
were matched with similar patients without cancer to
compare risk factors) from the UCLA lab of Dr. Donald
Tashkin, one of the world's leading experts on the
pulmonary effects of drugs.
In the UCLA study, there was a consistent trend -- albeit
short of statistical significance -- toward lower cancer risk
among even the heaviest marijuana smokers. This was a
surprise to some, given that marijuana smoke contains
many of the same carcinogenic compounds as tobacco
smoke. The researchers wrote:
Although purely speculative, it is possible that
such inverse associations may reflect a protective
effect of marijuana. There is recent evidence from
cell culture systems and animal models that 9-tetrahydrocannabinol, the principal psychoactive ingredient in marijuana, and other cannabinoids
may inhibit the growth of some tumors by
modulating key signaling pathways leading to
growth arrest and cell death, as well as by inhibiting tumor angiogenesis. These antitumoral associations have been observed for several types of
malignancies including brain, prostate, thyroid,
lung, and breast.
In an October 2003 review in the journal Nature Reviews:
Cancer, Guzman detailed the extensive body of test-tube
and animal research showing that cannabinoids inhibit
tumors of the lung, uterus, skin, breast, prostate and brain
(including gliomas, the type of tumor that killed Sen.
Edward Kennedy). He also noted: "Cannabinoids have
favorable drug-safety profiles and do not produce the
generalized toxic effects of conventional chemotherapies.
Cannabinoids are selective antitumor compounds, as they
can kill tumor cells without affecting their non-transformed
counterparts."
Such selectivity is exactly what you want in an anticancer
drug. The reason chemotherapy can be so awful is that most
chemo drugs aren't selective enough; they kill cancer cells,
but are also toxic to healthy cells, leading to vomiting, hair
loss and other miseries.
The 'Cure'?
Nearly all of the evidence about cannabinoids as anticancer
drugs comes from lab studies using cell cultures or animals
with experimentally implanted tumors. The annals of
medical research are littered with drugs that looked
promising in the lab but didn't work in people. Still, that
doesn't stop some enthusiasts from touting cannabis as a
cure for cancer, sometimes making even open-minded
scientists and medical marijuana advocates nervous.
When I worked at the Marijuana Policy Project, we
received several impassioned emails imploring us to tell
Sen. Kennedy that cannabis could cure his brain tumor.
Others touted Canadian Rick Simpson's "Healing Hemp
Oil" Web site, Phoenix Tears.
In a series of videos, letters and other materials on the
site, Simpson -- who has had repeated run-ins with law
enforcement over his cannabis-related activities and was,
according to a Dec. 14 posting, staying in Europe
indefinitely to avoid arrest -- promotes what he calls
"hemp oil" as a "simple herbal cure for cancer. I have
used these extracts
to cure three areas of skin cancer on my own body, also,
I have cured cancers for others." Simpson also touts hemp
oil for pain and a variety of other conditions.
The site includes video and written instructions for making
the preparation. The procedure involves using a solvent
such as naphtha or isopropyl alcohol to extract the THC
from marijuana, then boiling off the solvent using a rice
cooker to leave a thick oil with a high THC concentration.
Simpson warns readers away from conventional cancer
treatments: "Hemp oil has a very high success rate in the
treatment of cancer, unfortunately many people who come
to me have been badly damaged by the medical system
with their chemo and radiation etc. The damage such
treatments cause have a lasting effect and people who
have suffered the effects of such treatments are the
hardest to cure."
He offers numerous stories and testimonials describing
seemingly hopeless cancers cured by hemp oil, but no
controlled, scientific experiments.
And critics find plenty to worry about. First, they note,
despite warnings and disclaimers on the site, the
procedure for making the medicine is risky. Mitch
Earleywine, author of Understanding Marijuana and a
professor of psychology at the State University of
New York at Albany, calls the do-it-yourself procedure
"outrageously dangerous. Even if you don't light yourself
on fire, you may end up with leftover solvent that would
slowly poison the healthiest of us."
There's a reason scientists don't base conclusions on
anecdotes, Earleywine explains. "Cancer remits
spontaneously sometimes, which is a good thing.
Unfortunately, it leads to superstitious conditioning so
people think that whatever they did last must be the
source of the cure. Especially with some cancers, where
a great many people die, all the spontaneous recoveries
associated with hemp oil get remembered while all those
that don't either get forgotten or attributed to the horrors
of the disease."
Earleywine stresses that he is not dismissing the possibility
that some form of cannabis might be an effective cancer
treatment. "THC killing tumors is actually true," he says,
"but we're not at the human stage [of research]."
Simpson is dismissive of critics who cite the lack of human
studies. "How are you going to do controlled studies when
it is illegal in Canada to do so?" he said in an emailed
response to questions.
In fact, researcher Mark Ware of McGill University in
Montreal has done clinical trials of medical cannabis in
Canada, including a study comparing several different
cannabis preparations in use by chronic pain patients.
Simpson calls the idea of spontaneous cancer remissions
"nonsense." As for possible risks of his preparation, he
argues, "It is irresponsible to give people liver toxic
chemicals, chemotherapy and radiation, so if they are
talking about irresponsible why do not look at their own
medical system? It is not irresponsible to save peoples
lives with a harmless natural, non-addictive medicine
from nature. If you watch our documentary, you will see
that I use a simple water purification process to get rid
of solvent residue. I have been ingesting oil for over
eight years and I have supplied this oil to thousands of
people who also have experienced no problems with
solvent residue."
While cautious about reports that are "solely anecdotal,"
Paul Armentano, deputy director and resident science
wonk at the National Organization for the Reform of
Marijuana Laws, lays blame for the lack of proper data
at the foot of prohibition. "It is a shame that lone
individuals must try and engage in the work that the
medical establishment should be undertaking, yet have
turned a blind eye to," he says. "Unfortunately, what we
have is speculation rather than hard science, and we only
have the politicization of cannabis to blame."
The Long and Winding Research Road
The one human study of a cannabinoid cancer treatment
published thus far was conducted by Dr. Guzman and
colleagues and published online in June 2006 by the
British Journal of Cancer. The scientists infused a THC
solution directly into the tumors of nine patients with
glioblastoma multiforme, a deadly form of brain cancer,
for whom standard treatments had failed. This small
pilot study wasn't aimed at proving that THC worked,
simply that it was safe to administer to these otherwise
doomed patients .
It proved entirely safe, with no negative effects attributed
to the THC and no "overt psychoactive effects." And while
there were no miracle cures, there were glimmers of
possible efficacy. In one patient with an "extremely
aggressive" cancer, tumor growth was curbed for nine
weeks. In another, symptoms improved, although tumor
growth was not stopped. And in some cases, lab tests with
cells taken from tumor biopsies showed that THC
decreased the number of viable cancer cells.
Guzman and colleagues noted that THC may not be the
best cannabinoid to use as a cancer treatment, as others
have been shown more potent in lab tests. And while the
direct infusion technique delivered a high THC
concentration to specific locations, it may not have
reached all parts of these large tumors.
Still, the results were positive enough that the researchers
urged further tests, including studies of cannabinoids in
combination with other cancer drugs. Guzman is hoping to
do more studies, but notes that with all the bureaucratic,
procedural and financial hurdles, "The way ahead is long
and winding."
But if more human studies aren't happening yet, lab work
continues to produce intriguing results. Just this month,
the journal Molecular Cancer Therapeutics published a
new study providing the first evidence that combination
cannabinoid therapy is more potent than using THC or
other cannabinoids as single agents.
Sean McAllister and colleagues from the California Pacific
Medical Center Research Institute in San Francisco tested
THC, cannabidiol (CBD) and both drugs combined on
human glioblastoma cell lines. In two of the three cell lines
tested, the THC/CBD combination proved the most potent
-- more so than would be expected by just adding the
anticancer effects of the two drugs together, suggesting
a synergistic action.
"Combinations, compared to individual drug treatments
with specific cannabinoid-based compounds, may represent
an improvement for the treatment of patients with
glioblastoma and perhaps additional cancers," McAllister
says. "It is also possible that other constituents of
Cannabis sativa which are not structurally related to
cannabinoids could improve antitumor activity when
combined."
That leads to an obvious question: Why not use the whole
plant -- whether smoked, vaporized, or in some sort of
extract like Simpson's? "In regard to brain cancer, it is
highly unlikely that effective concentrations of either
Δ9-THC or CBD could be reached by smoking cannabis,"
McAllister says. "In regard to additional cancers, I feel
defined formulations and dosing will be needed in order
to effectively treat patients."
McAllister says his team is moving toward "clinical trials
in both breast and brain cancer, but it is a slow process."
The next step, he says, will be to try to replicate his
test-tube results in animals. "No agency in the U.S. would
allow me to move forward to clinical trials without some
form of proof of concept data in a relevant preclinical in
vivo model."
That may be an accurate assessment, but Armentano
thinks it's too cautious "given the long established safety
of cannabinoids, including THC which is already a legal
pharmaceutical, and CBD, which is non-psychoactive, is
not a central nervous system depressant and has no risk
of overdose."
Not only is there abundant evidence that cannabinoids kill
cancer cells, Armentano says, "Investigators now even
understand the mechanism of action; in other words, they
know how and why cannabinoids kill cancerous cells and
halt the spread of malignant tumors."
The question of whether these cannabis compounds can
cure cancer in people, he says, "ought to have been already
answered decades ago."
consultant who served as director of communications for
the Marijuana Policy Project from 2001 to2009.
Share
Send this 
Print this 
RSS Feed 
Fran Korten wrote this article for 
