Intensive smoking cessation programs not only can help people stop smoking, but, for those who do quit, they also can significantly improve long-term survival, according to new results from the Lung Health Study (LHS) released today. Among the LHS participants randomly assigned to an intensive smoking cessation program, there was a 15 percent lower death rate at more than 14 years of follow-up. The finding, the study authors stressed, is striking because the intervention only led to cessation at 5 years in less than one-quarter of participants. However, of the 22 percent of participants who were able to stop smoking for 5 years, 90 percent continued to abstain at 11 years, compared with just 5 percent of those randomly assigned to usual care.

In addition to the overall survival findings, lead author Dr. Nicholas Anthonisen from the University of Manitoba and colleagues reported death rates from lung cancer were also lower in the special intervention group than the usual care group. This is the first time, the authors noted, that such data have been reported "in the context of a clinical trial." The data, they continued, "are consistent with those of previous cohort and case control studies that showed that measurable effects of cessation on lung cancer are usually not evident in the first 5 years, and that lung cancer risk is probably still elevated after 15 years of cessation."

Dr. Scott Leischow, chief of the NCI Tobacco Control Research Branch, called the reduction in lung cancer incidence "one of the study's most critical findings." It also demonstrates again, he continued, "that after smoking prevention, smoking cessation is the single most effective method to prevent lung cancer; the study showed that lung cancer deaths were decreased more than 50 percent within 15 years of complete smoking cessation."

The study - sponsored by the National Heart, Lung, and Blood Institute and published in the February 15 Annals of Internal Medicine - was launched in 1986 and followed nearly 5,900 middle-aged smokers who had mild to moderately abnormal lung function but were otherwise healthy at enrollment. Participants were assigned to either a 10-week intensive smoking cessation program (see sidebar) or to usual care. There were 731 deaths: 33 percent due to lung cancer (240 cases), 22 percent due to cardiovascular disease (163 cases), and 21 percent (154) due to cancers other than lung.

Participants 45 and younger saw the biggest survival benefit from the specialized intervention, which, the authors argued, demonstrated that smoking cessation was "most effective in preventing truly premature death."

Dr. Leischow agreed, adding that it also offers a critical public health message. "This argues for a continued emphasis on encouraging teens and young adults not to start smoking," he said. "But if a person is smoking, we need to get them to quit at the earliest possible age. It's critical that all health care providers be aggressive in helping smokers to quit, and to follow up and do what they can to help them maintain abstinence."

When the 5-year LHS results were published, the smoking cessation program was associated with a lower rate of lung function decline, but there were no differences between morbidity or mortality among treatment groups. But the results seen nearly a decade later, wrote Dr. Jonathan M. Samet of the Johns Hopkins School of Public Health in a related editorial, place a stamp of urgency on current antismoking efforts.

"If we are to begin to control the rising number of smoking-related deaths soon," Dr. Samet wrote, "we must increase rates of smoking cessation now, since we won't see the benefits for decades."

By Carmen Phillips