Cholangiocarcinoma in Denmark: Time-trends in incidence and mortality

Cholangiocarcinomas have a poor prognosis, and the incidence is rising in most countries. We examined time-trends in incidence and mortality in a nationwide Danish cohort.

We used nationwide health databases to identify all Danish citizens diagnosed with cholangiocarcinoma from 1995 to 2022. We computed age-standardised incidence rates, stage distribution, and age- and sex-adjusted 1-year mortality.

The median age of the 5,787 patients with cholangiocarcinoma was 72 years, and 53% were female. Overall, the age-standardised incidence rate per 100,000 person-years almost doubled, from 3.93 (95% CI 3.59-4.26) in 1995-1998 to 6.79 (6.42-7.16) in 2019-2022. This rate increased five-fold for intrahepatic cholangiocarcinoma from 0.75 (0.61-0.90) in 1995-1998 to 3.85 (3.57-4.13) in 2019-2022, while for extrahepatic cholangiocarcinoma it decreased from 2.42 (2.16-2.69) in 1995-1998 to 1.30 (1.14-1.47) in 2019-2022. Although individuals aged 18-59 years had the lowest incidence rate of cholangiocarcinoma (any type), they experienced the steepest annual increase (3.2% vs. 2.7% in those aged 60-79 and 2.1% in those ≥80 years; p for interaction = 0.01). Among all patients with cholangiocarcinoma, the proportion with localised resectable disease increased from 7% in 2004-2006 to 12% in 2019-2022. We saw a decrease in age- and sex-adjusted 1-year mortality between 1995 and 2022: 81% (77-84) in 1995-1998 vs. 65% (63-68) in 2019-2022. The decrease in 1-year mortality was universal, with the largest decrease in patients aged 18-59 years (from 67% in 1995-1998 to 49% in 2019-2022) and in 60-79-year-olds.

The incidence of cholangiocarcinoma in Denmark increased in 1995-2022, driven by an increasing incidence of intrahepatic cholangiocarcinoma. Meanwhile, 1-year mortality decreased, likely reflecting earlier diagnosis and better treatments.

Cholangiocarcinomas have a poor prognosis, and the incidence is rising in most countries. In Europe, all countries but Denmark have shown an increasing incidence of intrahepatic cholangiocarcinoma. The incidence of cholangiocarcinoma in Denmark between 1995 and 2022 increased, driven by a large increase in intrahepatic cholangiocarcinomas. The proportion with localised resectable disease increased while 1-year mortality decreased, though it remained high (65% in 2019-2022). Knowledge of incidence and mortality risk is valuable for doctors to understand the disease, identify risk factors, and design preventive care studies; for healthcare providers to allocate resources; and for patients to understand their prognosis.