Clinical research published in a journal of the American Association for Cancer Research showing that marijuana's components can inhibit the growth of cancerous brain tumours is the latest in a long line of studies demonstrating the drug's potential as an anti-cancer agent.
This latest study, performed by researchers at Madrid's Complutense University, found that cannabis restricts the blood supply to glioblastoma multiforme tumours, an aggressive brain tumour that kills some 7,000 people in the United States every year. But despite the value of such findings both in terms of the treatment of life-threatening illnesses and as news, U.S. media coverage has been almost non-existent.
Why the blackout? Not one such study has been acknowledged by the U.S. government.
This wasn't always the case. In fact, the first experiment documenting pot's anti-tumour effects took place in 1974 at the Medical College of Virginia at the behest of the U.S. government.
It showed that marijuana's 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 per cent."
Despite these favourable preliminary findings, U.S. government officials refused to fund any follow-up research for two decades, until it conducted a similar - though secret - clinical trial in the mid-1990s.
That study, carried out by the U.S. National Toxicology Program, concluded that mice and rats administered high doses of THC over long periods had greater protection against malignant tumours than untreated controls.
Rather than publicize these findings, government researchers shelved the results, which only became public after a draft copy of the findings were leaked in 1997 to a medical journal that in turn forwarded the story to the national media.
However, in the eight years since then, the U.S. government has yet to fund a single additional study examining the drug's potential anti-cancer properties. Is this a case of federal bureaucrats valuing politics more than the health and safety of patients? You be the judge.
Fortunately, scientists overseas have generously picked up where U.S. researchers so abruptly left off.
This month, researchers at the University of Milan in Italy, reported that marijuana's constituents inhibit the spread of brain cancer in human tumour biopsies from patients failed by standard cancer therapies.
Last year, the same researchers reported in the Journal of Pharmacology and Experimental Therapeutics that non-psychoactive compounds in marijuana inhibited the growth of glioma cells in a dose-dependent manner and selectively targeted and killed malignant cells, stimulating them to "commit suicide" in a natural process called apoptosis.
In 2000, a research team at Complutense's department of biochemistry and molecular biology reported in the journal Nature Medicine that injections of synthetic THC eradicated malignant gliomas (brain tumours) in one-third of treated rats. The study was undertaken after the discovery in 1998 that THC can selectively induce apoptosis in brain tumour cells without negatively affecting the surrounding healthy cells.
Nevertheless, federal officials in the U.S. continue to refuse to express any interest in funding - or even acknowledging - this clinical research.