Pancreatic cancer is the 5th leading cause of death from cancer, largely because the prognosis is so poor.
Dutch researchers monitored the progress of 2633 patients who underwent surgery for the removal of a peptic or duodenal ulcer between 1931 and 1960.
A preliminary analysis suggested that these patients had double the risk of developing pancreatic cancer.
The researchers wanted to find out if the risk increased with length of survival after surgery, and if there were any genetic differences between patients developing the disease after surgery and those who developed it spontaneously.
Since the date of the preliminary analysis in 1988, a further 361 patients had died, leaving just 462 survivors.
Data analysis showed that the risk of developing the disease increased continuously over time, more than tripling after 35 years.
Sex, type of procedure, and indication for surgery did not influence the findings.
To date, 39 patients have died of pancreatic cancer, with 35 deaths 5 or more years after surgery.
| Risk of pancreatic cancer tripled after 35 years following surgery.
| Journal of Clinical Pathology |
However, data on smoking, a known risk for pancreatic cancer, were not complete.
Death rates from lung cancer were higher than would be expected for the general population.
However, the authors say that lung cancer patterns did not resemble those of pancreatic cancer in this group. This suggests that, while smoking may contribute to the increased risk of pancreatic cancer, it is the surgery itself that accelerates cancerous changes.
This is borne out by the finding of the same genetic mutations in patients who developed the disease, irrespective of ulcer surgery, say the authors.
A possible explanation, they say, is that surgery deprives the stomach of its acid, so creating an environment in which nitrate-producing bacteria thrive.
This increases production of cancer-causing compounds, such as nitrosamines, which have been associated with pancreatic cancer in animals.