Second Opinion: Should Ex-Smokers Quit the Patch?

Researchers have long assumed that it was tobacco's tar and carcinogenic chemicals that were primarily to blame for many lung cancers. But a new study suggests that nicotine also plays a critical role in promoting lung cancer and increasing its risk. If so, what does that mean for ex-smokers who rely on nicotine patches, gums and sprays? "Smokers who can quit should quit," says Dr. Phillip Dennis, lead author of the recent study in the Journal of Clinical Investigation. "If you need a supplement, don't do it without medical supervision." Nicotine itself may not be a cancer-causing agent, but, according to Dennis, it activates a pathway in cancerous and normal lung cells that keeps cells alive even when they are damaged and should naturally die. As healthy cells acquire genetic defects from cigarette smoking, nicotine may force them to survive in their damaged, precancerous state until they collect so many mutations that they become fully cancerous. The study looked only at lung cells, but Dennis says nicotine may play a similar role in other tobacco-related cancers. --By Sora Song