HOLLYWOOD, FLA. — Cigarette smoking plays a role in both the initiation and progression of pancreatic cancer, based on an analysis of more than 18,000 patients with the disease.
“To our knowledge, this is the first compelling evidence for a role of cigarette smoking early in the neoplastic transformation of the pancreas,” Randall E. Brand, M.D., said at a symposium on gastrointestinal cancers sponsored by the American Society of Clinical Oncology.
“Eventually, we will use screening tests for pancreatic cancer, and people who smoke should be screened at an earlier age than nonsmokers,” said Dr. Brand, a gastroenterologist at Northwestern University in Chicago.
The study used data in the Cancer Information Resource File from more than 350 U.S. teaching and community hospitals. The database included records for 18,346 people with pancreatic cancer who had information on smoking history in their files.
The analysis split the patients into four categories: never smokers, prior smokers, current smokers, and ever smokers (current and prior smokers combined). Current smokers were considered to be people who smoked cigarettes either at the time their pancreatic cancer was first diagnosed or within 1 year preceding their diagnosis.
The mean age at diagnosis was 63 years among current smokers, 67 years among ever smokers, 70 years among prior smokers, and 73 years among never smokers.
The finding that prior smokers developed pancreatic cancer at a younger age than never smokers suggests that smoking contributes to the initiation of pancreatic cancer. And the finding that current smokers developed pancreatic cancer at an even younger age suggests that smoking also plays a role in disease progression, Dr. Brand said.
“We were surprised by the magnitude of the effect. We had anticipated that it would be a few years at most, not the dramatic 7 to 10 years that we saw,” Dr. Brand said at the symposium, also sponsored by the American Gastroenterological Association, the American Society for Therapeutic Radiation and Oncology, and the Society of Surgical Oncology.
It is not known how cigarette smoke affects the pancreas. The immune effects of smoking may mediate development of pancreatic cancer, and a carcinogen pres-ent in tobacco smoke may accumulate in the pancreas.