Smokeless and Other Noncigarette Tobacco Use and Pancreatic Cancer: A Case-Control Study Based on Direct Interviews Juan Alguacil and Debra T. Silverman Division of Cancer Epidemiology and Genetics. National Cancer Institute, NIH, Department of Health and Human Services, Bethesda, Maryland Abstract Cigarette smoking is an important and well-established cause of pancreatic cancer. In contrast, little is known about the effects of smoking cigars, pipes, and use of smokeless tobacco on pancreatic cancer risk. The objective of the present study was to examine the association between noncigarette tobacco use (i.e., cigars, pipes, smokeless tobacco) and pancreatic cancer risk among nonsmokers of cigarettes. A population-based case-control study of pancreatic cancer was conducted during 1986 –1989 among residents of Atlanta, Georgia, Detroit, Michigan,, and 10 counties in New Jersey. Direct interviews were successfully completed with 526 newly diagnosed pancreatic cancer patients and 2153 controls ages 30 –79 years. This analysis was restricted to lifelong nonsmokers of cigarettes and based on interviews with 154 cases newly diagnosed with carcinoma of the exocrine pancreas and 844 population controls who reported no history of cigarette smoking. We observed a consistent pattern of increased risk associated with cigar smoking, although these elevations were not statistically significant. Participants who smoked cigars regularly (i.e., at least one cigar/week for >6 months) experienced a 70% increased risk [95% confidence interval (CI): 0.9 –3.3], and those who never used other form of tobacco had a 90% increased risk (95% CI: 0.8 – 4.3). Risk was elevated among those who smoked more than one cigar/day [odds ratio (OR)  1.8; 95% CI: 0.8 – 4.2) and among those who smoked cigars > 20 years (OR  1.9; 95% CI: 0.9 – 3.9). Trends in risk with increasing amount and duration smoked were consistent but not statistically significant (P  0.17 and P  0.16, respectively). Subjects who used smokeless tobacco regularly had a 40% increased risk of pancreatic cancer (95% CI: 0.5–3.6) compared with nonusers of tobacco. We observed a marginally significant increasing risk with increased use of smokeless tobacco (P  0.04); participants who used >2.5 oz of smokeless tobacco a week had an OR of 3.5 (95% CI: 1.1–11). Long-term use of smokeless tobacco (i.e., >20 years) was also associated with a nonsignificant increased risk (OR  1.5; 95% CI: 0.6 – 4.0). In contrast, pipe smokers experienced no increased risk (OR  0.6; 95% CI: 0.1–2.8). Our results suggest that heavy use of smokeless tobacco, and to a lesser extent, cigar smoking may increase the risk of pancreatic cancer among nonsmokers of cigarettes. Introduction Noncigarette tobacco use has been increasing in the United States since the early 1990s (1, 2), heightening awareness of the health effects of use of noncigarette tobacco. Recent results from the American Cancer Society Prospective Cancer Preven- tion Study suggest that men who smoked cigars, but not ciga- rettes or pipes, are at increased risk of several sites of cancer known to be associated to cigarette consumption, including lung, esophagus, larynx, oral cavity, and possibly pancreas (3). Cigarette smoking is an important and well-established cause of pancreatic cancer. In contrast, little is known about the effect of noncigarette tobacco use on pancreatic cancer risk. Studies of the noncigarette tobacco use pancreatic cancer association have been hampered by the relatively few nonsmokers of cigarettes who used other forms of tobacco. Exclusion of cigarette smok- ers from such studies is important to estimate the independent effect of noncigarette tobacco use. Additional limitations of most case-control studies of pancreatic cancer include misclas- sification of disease and low response rates because of the rapid fatality from this disease (4 – 6). Patterns of risk by type of tobacco use coupled with information about differences in the putative carcinogens present in these types of tobacco may help to identify the human pancreatic carcinogens present in to- bacco. The purpose of our study was to estimate the risk of pancreatic cancer associated with smoking cigars, pipes, and use of smokeless tobacco. Materials and Methods Detailed methods have been described previously (5). Briefly, this population-based case-control study was initiated simulta- neously with case-control studies of three other malignancies (i.e., esophagus, prostate, and multiple myeloma). The case series included all cases of carcinoma of the exocrine pancreas (International Classification of Diseases for Oncology code = 157) newly diagnosed from August 1986 through April 1989 among 30 –79-year-old residents of geographic areas covered by population-based cancer registries located in Atlanta, Geor- gia (DeKalb and Fulton counties); Detroit, Michigan (Macomb, Oakland, and Wayne counties); and the state of New Jersey (10 counties). Despite a relatively short median time from diagnosis to interview (7 weeks), 471 of the 1153 patients initially iden- Received 4/24/03; revised 9/15/03; accepted 9/18/03. Grant support: National Cancer Institute Grants NO1-CP-51090, NO1- CP51089, NO1-CP51092, NO1-CN-05225, NO1-CN-31022, and NO1-CN- 05227. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Requests for reprints: Debra T. Silverman. Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Department of Health and Human Services, 6120 Execu- tive Boulevard, EPS 8108, Rockville, MD, 20852. Phone: (301) 435-4716; Fax: (301) 402-1819; E-mail: silvermd@mail.nih.gov. 55 Vol. 13, 55–58, January 2004 Cancer Epidemiology, Biomarkers & Prevention on April 2, 2017. © 2004 American Association for Cancer Research. cebp.aacrjournals.org Downloaded from