The researchers assessed the risk of bowel cancer after cholecystectomy, and reported their findings in the September issue of Gastroenterology.
Cholecystectomized patients were identified through the Swedish Inpatient Register, from 1965 through 1997. They were then followed up for subsequent cancer.
Standardized incidence ratio (SIR) was used to estimate relative risk of cancer.
In total, 278,460 cholecystectomized patients (contributing 3,519,682 person-years) were followed up for a maximum of 33 years after surgery.
The team found that cholecystectomized patients had an increased risk of proximal intestinal adenocarcinoma, which gradually declined with increasing distance from the common bile duct.
The risk was significantly increased for adenocarcinoma (SIR, 1.77) and carcinoids of the small bowel (SIR, 1.71), and right-sided colon cancer (SIR, 1.16).
However, no association was found with more distal bowel cancer.
|Post-cholecystectomy increased risks:|
Adenocarcinoma small bowel:
Carcinoid small bowel:
Right-sided colon cancer:
The gradient was further pronounced when surgery of the common bile duct was included.
The associations were found to remain increased up to 33 years after cholecystectomy.
No differences between sexes were observed.
Jesper Lagergren and fellow colleagues, of the Karolinska Institute, commented that cholecystectomy increases the risk of intestinal cancer, a risk that declines with increasing distance from the common bile duct.
Changes in the intestinal exposure to bile might be the underlying biological mechanism, they concluded.