NORML's Paul Armentano has a disturbing account of the history of government research regarding the benefits of THC as a potential cancer treatment:
Not familiar with this scientific research? Your government is.
In fact, the first experiment documenting pot's potent anti-cancer effects
took place in 1974 at the Medical College of Virginia at the behest federal
bureaucrats. The results of that study, reported in an Aug. 18, 1974,
Washington Post newspaper feature, were that marijuana's primary
psychoactive component, 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."
Despite these favorable preliminary findings (eventually published the
following year in the Journal of the National Cancer Institute), U.S.
government officials refused to authorize any follow-up research until
conducting a similar - though secret - clinical trial 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
However, rather than publicize their findings, government researchers
shelved the results, which only became public after a draft copy of its
findings were leaked to the medical journal AIDS Treatment News, which in
turn forwarded the story to the national media. [timesheraldonline.com]
They haven't studied the issue since. And because the U.S. government holds a monopoly on "legal" marijuana that could be used for research purposes, they've been able to prevent independent researchers from further investigating marijuana's promising anti-cancer properties. Armentano notes that research overseas continues to produce very encouraging results.
Unfortunately, our government's blockade against marijuana/cancer research is so mindless and vindictive that it's almost impossible to convince anyone that they do things like this. It's a terrible and frequent conundrum for reformers that if we accurately describe the behavior of our opposition, we end up sounding crazy.