Pubdate: Tue, 28 Dec 1999 Source: New York Times (NY) Copyright: 1999 The New York Times Company Contact: http://www.nytimes.com/ Forum: http://www10.nytimes.com/comment/ A DOWNER FOR AGING MARIJUANA USERS At Risk Smoking marijuana significantly increases the risk of head and neck cancers, according to a new study, which also predicts more cases as baby boomers age. The researchers, led by Dr. Zuo-Feng Zhang, a professor of epidemiology at the Jonsson Cancer Center at the University of California at Los Angeles, found that marijuana was almost as damaging as tobacco in terms of respiratory tract cancer, despite the fact that the drug was generally regarded as safer. The study, published last week in the journal Cancer Epidemiology, Biomarkers and Prevention, compared the use of marijuana, tobacco and alcohol by 173 patients suffering from head or neck cancers to the habits of a control group of 176 cancer-free patients. Dr. Zhang said that marijuana users faced 2.5 times the risk of cancer as nonusers. Tobacco increased the risk 3.5 times, he said, and people who smoked both tobacco and marijuana raised their risk 36 times. A larger study now under way,is needed to confirm the results, he said. Meanwhile, he said that people who smoked marijuana in their youth should have regular examinations for the early warning signs of throat, tongue or other cancers. "If you consider the latency time, about 30 years, we could well have an increase in the next 5 or 10 years," he said. "But many of these cancers are easy to treat if they are caught early." - --- MAP posted-by: Richard Lake