Bark with A Bite

MORE THAN 20,000 AMERICAN WOMEN ARE DIAGnosed each year with ovarian cancer, many with the disease in an advanced stage, and chemotherapy seldom helps prolong their life. There is one effective treatment: taxol, a substance found in the bark of the Pacific yew tree. Taxol doesn't cure the cancer but does slow its progress for months in up to 30% of patients. Now it has received the blessing of both the U.S. Food and Drug Administration and Canadian authorities as an approved treatment for ovarian cancer. It is also being investigated for possible effectiveness in combatting breast and other cancers. The only catch: treating one patient takes four trees' worth of bark, and Pacific yews, which grow in protected forests in the Pacific Northwest, are rare. But taxol seems to be available from the trees' needles as well, and pharmaceutical firms are working to synthesize it in the lab. Scientists may be able to resolve the conflict between preserving wilderness and saving human lives.