The main active ingredient in marijuana did not cause cancer, and may even have protected against malignancies, when fed to laboratory animals in huge doses over long periods, according to a federal study left on the shelf for 2 1/2 years.
The 126-page draft study, which undercuts federal officials' contention that marijuana is carcinogenic, has never been published, though a panel of expert reviewers found in June 1994 that its scientific methods and conclusions were sound.
The ignored $2 million federal study may add fuel to the national debate over the medical use of marijuana. That debate escalated today when the respected New England Journal of Medicine called on the government to reclassify marijuana so it can be prescribed by doctors for medical purposes.
In an editorial headlined "Federal Foolishness and Marijuana," the journal sharply criticizes White House antidrug policy adviser Barry R. McCaffrey, US Attorney General Janet Reno and Health and Human Services Secretary Donna Shalala for their firm stance against the use of marijuana to relieve nausea, vomiting and pain from a number of diseases.
"I believe that a federal policy that prohibits physicians from alleviating suffering by prescribing marijuana for seriously ill patients is misguided, heavy-handed and inhumane," writes Dr. Jerome P. Kassirer, the journal's editor in chief.
Kassirer called McCaffrey, Reno and Shalala "hypocritical" for their stance against the use of marijuana as medicine for dying patients, since addiction and long-term side effects are irrelevant in such situations.
He also said that controlled human trials of marijuana for dying or seriously ill patients are not necessary. "What really counts for a therapy with this kind of safety margin is whether a seriously ill patient feels relief as a result of the intervention, not whether a controlled trial `proves' its efficacy," Kassirer wrote.
Drug policy observers said the New England Journal's stand is likely to have considerable influence on the marijuana debate, touched off last fall when California and Arizona voters approved ballot questions authorizing medical use of pot.
"I think it will have a major impact," said Dr. Herbert Kleber of Columbia University's Center on Addiction and Substance Abuse. "The New England Journal of Medicine is one of the most prestigious medical journals in the country."
Kleber said he was disappointed in Kassirer's position, partly because it will further erode societal disapproval of marijuana, a factor that some studies have tied to the likelihood that adolescents will try the substance.
The New England Journal's stance brought a rebuttal from McCaffrey. "We have great respect for the opinions of the New England Journal of Medicine, and we are taking them into account," McCaffrey said. "However, we must remember that in our country ... medicines need to pass scientific scrutiny and be subject to peer group review before they are made available to the American people."
A spokesman for McCaffrey said his office was not aware of the National Toxicology Program study, which was first revealed this month by a newsletter called AIDS Treatment News.
The Department of Health and Human Services, which has blocked human studies of marijuana since 1992, responded to the journal's editorial with a statement that stressed the agency's openness to research.
"We are moving aggressively to resolve questions about the alleged therapeutic value of marijuana," said Dr. Philip R. Lee, assistant secretary for health. He noted that the Clinton administration is embarking on a $1 million review of available scientific evidence on marijuana.
The Massachusetts Department of Public Health, which last week proposed a mechanism to certify patients with several diseases to use marijuana, yesterday sent a letter to Shalala asking her to make the drug available here for a clinical trial. The federal government grows research-grade pot at a heavily guarded farm in Mississippi.
"We are willing to either get it from them or grow it with their approval," said state Health Commissioner David Mulligan.
The National Toxicology Program study is one of the largest efforts to determine if marijuana's main active ingredient, tetrahydrocannabinol or THC, causes cancer in laboratory animals. It involved 35 researchers and 12 reviewers and was overseen by the FDA, the National Cancer Institute and other federal agencies.
"We found absolutely no evidence of cancer," said John Bucher, the National Toxicology Program's deputy director. In fact, animals that received THC had fewer cancers, possibly because they were leaner.
Bucher said the report's publication was overdue. "We should have had it out sooner."
In the study, high doses of THC were delivered directly into the stomachs of mice and rats daily for two years. Since the animals were not exposed to marijuana smoke, the study did not address the carcinogenic potential of inhaled marijuana.
Bucher said his agency had not been pressured to bury the report, and said the delay was due to a personnel shortage.
Larry Tye of the Globe staff contributed to this report.
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