A PROSPECTIVE-STUDY OF CIGARETTE-SMOKING AND THE RISK OF PANCREATIC-CANCER

Objectives: To prospectively examine the excess incidence of pancreati c cancer among cigarette smokers and to examine the influence of smoki ng cessation on the risk of pancreatic cancer. Methods: We obtained da ta on cigarette smoking and other risk factors for pancreatic cancer f rom 118 339 women aged 30 to 55 years and 49 428 men aged 40 to 75 yea rs who were without diagnosed cancer. During the 2 116 229 persons-yea rs of follow-up, pancreatic cancer was diagnosed in 186 participants. Results: The multivariate relative risk of pancreatic cancer for curre nt smokers was 2.5 (95% confidence interval, 1.7-3.6). A significant, positive trend in risk with increasing pack-years of smoking was obser ved (P for trend=.004), although this association was confined to ciga rette consumption within the past 15 years. Compared with participants who continued to smoke, former smokers had a 48% reduction in pancrea tic cancer risk within 2 years of quitting. Ultimately, the relative r isk of pancreatic cancer among former smokers approached that for neve r smokers after less than 10 years of smoking cessation. Overall, the proportion of pancreatic cancers attributable to cigarette smelting wa s 25%. Conclusions: Cigarette smoking is associated with an increased risk of pancreatic cancer. The rapid reduction in risk associated with quitting suggests that smelting cessation could eliminate 25% of the 27 000 deaths from pancreatic cancer occurring annually in the United States.