Some autoimmune diseases are associated with increased risk of liver cancer.
However, there has been no comprehensive evaluation of autoimmune diseases among patients who develop different subtypes of hepatobiliary cancer.
Dr Felipe Castro and colleagues examined the association between autoimmune diseases and cancers of the liver and biliary tract in the Swedish population.
The research team analyzed data from national datasets at the Center for Primary Health Care Research.
Data on patients with autoimmune disorders were retrieved from the Swedish Hospital Discharge Register, from 1964 through 2008, of which 33 diseases were evaluated.
|Primary biliary cirrhosis and autoimmune hepatitis had the strongest association with liver cancer|
|Clinical Gastroenterology & Hepatology|
Hepatobiliary cancer cases were retrieved from the Swedish Cancer Registry.
The researchers calculated standardized incidence ratios (SIRs) and hazard ratios for incident cancers and deaths from hepatobiliary cancers.
Among 402,462 patients with autoimmune disorders, 582 were diagnosed with primary liver cancer, 330 with gallbladder cancer, 115 with extrahepatic bile duct cancer, and 43 with ampulla of Vater cancers.
The team identified 14 autoimmune conditions that were significantly associated with increased risk of primary liver cancer, 5 conditions associated with gallbladder cancer, and 3 associated with extrahepatic bile duct cancer.
The autoimmune disorders with the strongest association with primary liver cancer were primary biliary cirrhosis and autoimmune hepatitis.
The researchers found that ulcerative colitis was strongly associated with extrahepatic bile duct cancer.
Celiac disease, Crohn’s disease, systemic sclerosis, and ulcerative colitis were associated with at least 2 types of cancer.
The team noted that increased hazard ratios were observed only for patients with biliary tract cancer who had been hospitalized for autoimmune conditions.
Dr Castro's team concludes, "In a study of the Swedish population, we identified an increased risk of hepatobiliary cancers among individuals diagnosed with autoimmune disease."
"Associations among different cancer types indicate that shared immunomodulatory mechanisms determine susceptibility to hepatobiliary cancer."