- Jeffrey E Harris, professor ()1,
- Michael J Thun, vice president for epidemiology and surveillance research2,
- Alison M Mondul, research analyst2,
- Eugenia E Calle, director, analytic epidemiology2
- 1Department of Economics, Massachusetts Institute of Technology, Cambridge MA 02139, USA,
- 2Epidemiology and Surveillance Research, American Cancer Society, 1599 Clifton Road NE, Atlanta GA 30329, USA
- Correspondence to: J E Harris Internal Medicine Associates, Massachusetts General Hospital, Boston MA 02114 USA
- Accepted 7 November 2003
Objective To assess the risk of lung cancer in smokers of medium tar filter cigarettes compared with smokers of low tar and very low tar filter cigarettes.
Design Analysis of the association between the tar rating of the brand of cigarette smoked in 1982 and mortality from lung cancer over the next six years. Multivariate proportional hazards analyses used to assess hazard ratios, with adjustment for age at enrolment, race, educational level, marital status, blue collar employment, occupational exposure to asbestos, intake of vegetables, citrus fruits, and vitamins, and, in analyses of current and former smokers, for age when they started to smoke and number of cigarettes smoked per day.
Setting Cancer prevention study II (CPS-II).
Participants 364 239 men and 576 535 women, aged 30 years, who had either never smoked, were former smokers, or were currently smoking a specific brand of cigarette when they were enrolled in the cancer prevention study.
Main outcome measure Death from primary cancer of the lung among participants who had never smoked, former smokers, smokers of very low tar cigarette filter, low tar (8-14 mg) filter, high tar (22 mg) non-filter brands and medium tar conventional filter brands (15-21 mg).
Results Irrespective of the tar level of their current brand, all current smokers had a far greater risk of lung cancer than people who had stopped smoking or had never smoked. Compared with smokers of medium tar (15-21 mg) filter cigarettes, risk was higher among men and women who smoked high tar (≥22 mg) non-filter brands (hazard ratio 1.44, 95% confidence interval 1.20 to 1.73, and 1.64, 1.26 to 2.15, respectively). There was no difference in risk among men who smoked brands rated as very low tar (1.17, 0.95 to 1.45) or low tar (1.02, 0.90 to 1.16) compared with those who smoked medium tar brands. The same was seen for women (0.98, 0.80 to 1.21, and 0.95, 0.82 to 1.11, respectively).
Conclusion The increase in lung cancer risk is similar in people who smoke medium tar cigarettes (15-21 mg), low tar cigarettes (8-14 mg), or very low tar cigarettes (≤ 7 mg). Men and women who smoke non-filtered cigarettes with tar ratings 22 mg have an even higher risk of lung cancer.
Contributors JEH and MJT contributed to the conception and design of the study, analysis and interpretation of the data, and drafting the manuscript. AMM performed the data tabulations and statistical analyses. EEC directed data collection and analysis of the prospective cohorts followed by the American Cancer Society, on which this study was based. All contributors reviewed the manuscript before submission and publication. MJT is guarantor..
Funding No specific funding.
Competing interests JEH has testified as an expert witnesses on behalf of plaintiffs in tobacco-related litigation. MJT has testified as an uncompensated expert on behalf of plaintiffs and the American Cancer Society in tobacco-related cases.
Ethical approval Approved by the institutional review board at Emory University.
- Accepted 7 November 2003