Background In the U.S., the incidence of lung cancer varies by race, with rates being highest among black men. There are marked differences in smoking behavior between blacks and whites, but little is known regarding how these differences contribute to the racial disparities in lung cancer. Purpose To compare the lung cancer risk associated with smoking in 14,610 blacks and whites in the prospective cohort Atherosclerosis Risk in Communities study. Methods Smoking characteristics were ascertained at baseline and three follow-up visits in 1990-1992, 1993-1995, and 1996-1998 (response rates were 93%, 86%, and 80%, respectively), as well as from annual telephone interviews. Data were analyzed in the fall of 2012. Multivariable-adjusted proportional hazards models were used to calculate hazard ratios and 95% CIs for lung cancer. Results Over 20 years of follow-up (1987-2006), 470 incident cases of lung cancer occurred. Lung cancer incident rates were highest in black men and lowest in black women. However, there was no evidence to support racial differences in the associations of smoking status, intensity, or age at initiation with lung cancer risk (all pinteraction 0.25). The hazard ratio for those who started smoking at age 12 versus >22 years was 3.03 (95% CI=1.62, 5.67). Prolonged smoking cessation ( 10 years) was associated with a decrease in lung cancer risk, with equivalent benefits in whites and blacks, 84% and 74%, respectively (p bsubesub=0.25). Conclusions Smoking confers similar lung cancer risk in blacks and whites.
Bibliographical noteFunding Information:
The Atherosclerosis Risk in Communities (ARIC) study is carried out as a collaborative study supported by National Heart, Lung, and Blood Institute contracts (grant numbers HHSN268201100005C , HHSN268201100006C , HHSN268201100007C , HHSN268201100008C , HHSN268201100009C , HHSN268201100010C , HHSN268201100011C , and HHSN268201100012C ). supported by grant number UL1RR025005, a component of the NIH and NIH Roadmap for Medical Research. Studies on cancer in ARIC are also supported by the National Cancer Institute (grant number U01 CA164975-01 ). Cancer incidence data have been provided by Maryland Cancer Registry, Center of Cancer Surveillance and Control, Department of Health and Mental Hygiene, 201 W. Preston Street, Room 400, Baltimore MD 21201. We acknowledge the State of Maryland, the Maryland Cigarette Restitution Fund, and the National Program of Cancer Registries of the CDC for the funds that helped support the availability of the cancer registry data.
A.E. Prizment was supported as a post-doctoral fellow by training grant number T32CA132670 from the National Cancer Institute. J.H. Lubin was supported by the Intramural Research Program of the NIH, National Cancer Institute, Division of Cancer Epidemiology and Genetics. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute or the NIH. The authors thank the staff and participants of the ARIC study for their important contributions.