While patients with gastrointestinal cancer are at increased risk of cholangitis, it is less clear whether cholangitis is also a marker for occult gastrointestinal cancer.
If an undiagnosed cancer obstructs the bile duct system and causes cholangitis, the short-term risk of cancer will appear increased.
However, an increased long-term risk of cancer may originate from chronic inflammatory processes.
Dr Kirstine Kobberøe Søgaard and colleagues from Denmark assessed the risk of a gastrointestinal cancer diagnosis subsequent to a cholangitis diagnosis during a 17-year period in Denmark.
The researchers conducted a nationwide population-based cohort study by linking Danish medical registries during 1994–2010.
The team quantified the excess risk of cancer in cholangitis patients using relative and absolute risk calculations.
The team found that 4333 patients with cholangitis were followed for 17,222 person-years.
During the follow-up period, 477 gastrointestinal cancers occurred versus 59 expected, corresponding to a SIR of 8.12.
The research team found that risk was increased mainly for cancer in the small intestine, liver, gallbladder and biliary tract and pancreas.
The team noted that during the first 6 months of follow-up, 314 patients were diagnosed with gastrointestinal cancer, corresponding to a SIR of 49.8, and an EAR of 175.
Dr Søgaard's team commented, "Cholangitis is a marker of occult gastrointestinal cancer."