Pubdate: Tue, 26 Jan 2010
Source: AlterNet (US Web)
Copyright: 2010 Independent Media Institute
Author: Bruce Mirken


It's Not As Far-Fetched As It Sounds, but Some Enthusiasts May Be 
Going Too Far.

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

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

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

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

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

"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 UKP9-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

The question of whether these cannabis compounds can cure cancer in
people, he says, "ought to have been already answered decades ago."
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