Cigarette smoking and cancer of the pancreas: evidence from a population-based case-control study in Toronto, Canada.
Results are reported with respect to smoking data from a population-based case-control study of pancreatic cancer conducted in Toronto, Canada, between 1983 and 1986. Lifetime smoking histories were obtained for 249 cases and 505 controls. A statistically highly significant positive association was observed between lifetime cigarette consumption and risk of pancreatic cancer. There was a rapid decrease in risk with time for those who quit cigarette smoking, the risk for ex-smokers being the same as for lifetime non-smokers between 10 and 15 years after quitting. Limiting exposure to the 15 years prior to diagnosis considerably strengthens the association and leads to a much more clearly defined dose-response relationship with relative risks of 1.88, 4.61, and 6.52 for tertiles of consumption for current cigarette smokers compared with lifetime non-smokers (p trend less than 10(-5)). We conclude that the current data, together with those from previous studies, strongly support a causal relationship between cigarette smoking and risk of pancreatic cancer, and indicate that cessation of smoking is likely to prove a rapidly effective preventive measure for this major type of cancer.
Howe
G R
GR
NCIC Epidemiology Unit, University of Toronto, Ontario, Canada.
Jain
M
M
Burch
J D
JD
Miller
A B
AB
D000328:Adult; D000368:Aged; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects*; D013997:Time Factors