Smoking ups pancreatic cancer risk

Cigarette smoking boosts the risk of the pancreatic cancer. Also, given an equal total exposure to smoking, a person who smoked less for a longer period of time would be at greater risk of pancreatic cancer than someone who smoked more for a shorter period of time.

Smoking is a known risk factor for pancreatic cancer. To better understand how patterns of exposure to cigarettes may relate to disease risk, researchers from USA analysed data for 1,481 people with the disease and 1,539 healthy controls from the International Pancreatic Cancer Cohort Consortium.

The study found 15% of all pancreatic cases were due to cigarette smoking with smokers almost twice more likely than people who had never smoked to develop pancreatic cancer. Risk rose steadily with the number of cigarettes a person smoked daily, the length of time that they smoked, and the total smoking dose - i.e.the number of packs a person smoked daily and the number of years they smoked.

People who had quit smoking 10 years previously were still at increased risk of pancreatic cancer, while the risk for people who had quit for 15 years was similar to that of people who had never smoked.

As the number of pack-years increased, excess risk declined with the intensity of smoking exposure. This suggests that greater risk for a total exposure delivered at lower intensity than for an equivalent exposure delivered at higher intensity.

Similar risk patterns have been seen for lung cancer, bladder cancer, cancer of the oral cavity, kidney cancer, and esophageal cancer, which indicates that smoking may increase the risk of all of these cancer types through similar mechanisms.

The researchers recommend that as smoking is an established pancreatic cancer risk factor, smoking cessation continues to be an effective strategy for decreasing the burden of this disease.