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:i o. ~ THE INIPACI' OF II7W TAR/NICOTINE CIGARE= Much data has acctmtulated in recent years on the impact of the change to Iow tar/nicotine cigarettes on health effects of smoking. This paper will review some of our studies including: 1) an epidemiologic study that showed that those who srroked low T/N cigarettes had small but significantly lower mortality than those who scroked high T/N cigarettes; 2) an autopsy study that showed' far fewer histologic cellular changes in the.tracheo-bronchial tree in people who diedlin the seventies than in those who died 15 years previously; 3)~ a study that showed that people who switch to low T/N cigarettes do not necessarily srnoke more per day; and 4) a study that stowed smokers of low T/N cigarettes are able to quit at a higher rate than~srmkers of moderate or high T/N cigarettes. Cigarette srroking plays an irrportant role in the overall.. cancer trends. But, because of changes in smoking patterns, death rates in various age cohorts have differing trends. In f.hgland and'Wales, the death~rates fram lung cancer in men, ages 45-54 and 55-64, have been decreasing in the last 10-15 years, although the rates continue to rise in older men. In 1977, the overall age- standardizedirate for lung cancer in men dropped for the first time. In the U.S., the lung cancer rate for menieont'nues to increase, althoughithere is a tendency for the rates in younger men to level off. In wcmen, the mortality rates in both England and'Wales, and in the United States, continue to increase and they are increasing at a more rapid rate inlyounger than in older wanen. In the United States, an estimated 30 million people have quit snoking and there is a strong trend toward use of lower tar/nicotine cigarettes. Is there any evidence of the impact of these changes

C f a in smoking habits on present or future mortality of lung cancer and other diseases? Despite the fact that lung cancer in the United States has not decreased, the evidence fram several recent American Cancer Society studies that changing smoking patterns is having an effect is ecnpelling. We repo rted many years ago that those who quit ssroking have lower lung cancer rates than~those who continue to smoke. A few years ago, we published data fran our epidemi.ologic study showing that srokers of laa tar/nicotine cigarettes had lower mortality rates fran total deaths, coronary heart disease and lung cancer than those who smoked!high TIN cigarettes. 3mokers of moderate T/'Iv' cigarettes had intermediate rates. This analysis included the deaths in a 12-year period fran 1960-1971, and was a study of cigarette sroking groups matched oni sex, age, number of cigarettes smoked per day, age began~smoking, and. a number of other factors. Decreases in morta.lity ccmparing low to high T/I+d cigarettes for 2 periods of time (1960-65 and 1966-71) in both~ sexes averaged 16% for total deaths, 14% for coronary heart disease and 26% for lung cancer. The study also showed that death rates frcm all causes for non- smokers were between 57% and 76% of those of low T/N ssmkers. Lung cancer rates among non-smokers were only 9% that of low TIN smokers; zn~ fenales, the rates in ron---znokers were 22% to 43%of the low T/N smQkers. The number of cigarettes smoked per day was mpre 'u-portant than the T/N conte:nt. Smokers of less than 20 "high" T/N ciqarettes had lower rates than those who smke3'1-2 packs of "low" T/N cigarettes. Another aspect of the evidence concerning low T/YV smoking ecnes R frcm our studies with Dr. Oscar Auerbach of the Veterans Administration C W Hospital in East Orange, N.J., concerning changes in bronchial .1 W epithelium. The changes in the tracheobronchial epithelitan in~211 men W W _ GD - 2 - ~

who died in 1955-60 (group A) were ccrnpared to the epithelial changes in 234 men (group B) who~died between 1970-1977. All of the men in the latter group had to have smoked cigarettes lower in!T/N during the last 10-15 years of their lives than all of the men who died in the late-1950's. A totaJl of 20,424 slides were read blind and the following epithelial changes were recorded and transferred to cemputer for analysis: increase in cell rows (hyperplasia); lesions with cilia absent; percent of cells with atypical nuclei. The results showed that with respect to all of these changes, the men in group B had far fewer changes than men in group A within each rnmber of cigarettes srroked category. The most advanced change (carcincma-inr situ) was found in neither group A nor group B. In srokers in group A, 2.6% of the slides in those who smpked less than 1 pack a day had this finding; 13.2% of the slides in 1-2 packs a day smokers and 22.5% inthe 2+ packs a day group. In-group B, the percentages were 0.1%, 0.8%, and 2.2%, respectively. It has been sanetimes alleged that those who srroke cigarettes with low T/N; increase the number of cigarettes they smoke. Our latest ACS studies show that in 1972, 60% of inen and 52% of wamen sroked cigarettes with decreased T/N carpared to brands they were smaking in 1959. If the hypothesis were true for all snokers, we should have seen a remarkable growth in rnanber of cigarettes consured inthis country. In carqaaring the changes among those in our study who smoked in 1959 and 1972, 29% of the mPn who increased the T/N level in the cigarettes they smnked increased: the ntunber of cigarettes they smoked per day. Amng those who sroke3 cigarettes with decreased T/N levels, 31.5% increased the number they smoked per day.;Among females, the oonparable percentages were 36.7% and 41.3%. Thus, if there is an increase in rnanber srroked' when a srmker changes brands, it is very smal l incieed. Perhaps the rmst inportant effect of switching to low T/N cigarettes is that it appears to make it easier for srokers to quit. A- 3

C : periods. srmkers. The same pattern of quitting was observed~ when the Qmkers j,apre divided into categories by the arrount they smoked in 1959. The rate of quit ting smoking was inversely related to number of cigarettes smroked, but within each of four groups classified~by number smoked per day, the percent quit was highest in those who smoked low TIN cigarettes; next highest in nmoderate T/N.smokers; and lowest in high T/N srrokers. This was found both in: me.n and! wccnen in both time .By 1972, 41$ of the men srroking, low T/Bd cigarettes ini1965 had quit; only 35g' of the high TIN smokers had quit. Among females, 27% of the low T/N and'.20$ of the high T/N smpkers quit smpking. Those who smoked cigarettes, with medium T/N quit at rates in betweenilarr and high T/N We believe that all of these factors mentioned: a decrease in r.rortality attributable to massive numbers of people quitting smoking, or srnoking cigarettes with lower T/N; and the implications of less damage to the lungs as shown in autopsy studies will result in a leveling off and a drop in lung cancer rates in men in the near future. Tn wanP.n, it seems dbubtful if the upward trend will be halted for scme time to ccme. The changes that affect lung cancer morality are oocurring at a time when another inTzortant public health phencmenon is taking place. Death rates fran cardiovascular diseases have dropped considerably in the last 15-20 years. The coronary heart disease death rates in the U.S. have shown a 20% drop in mPn and 24% drop in wanen between 1969-76, the largest drop observed among a number of countries. Australia, Canada, Ilew Zealand, and Israel have also shown decreases but not as great. There has been virtually no change in coronary rates in the United Kingdan, and several European countries (Swedeni, France, Germany) have shown continuedincreases in males, but no change or small decreases infemales. The decreases in the United States have occurred in all diseases except for cancer, chronic pulmonary disease, and hcm.icide and suicide. T 4

r This has resulted in a remar}table 3-year gain in life expectancy in both men and wamen since 1970. And while the percent of heart disease as a cause of all deaths has been~decreasing in the last ~ 10 years, the percent that cancer is as a cause of all deaths has been~increas'uzg fran about 19% in fenales in the 1960's to 24% in 1977. In males, the percent has increased fran about 16% to 20$. -• 5