Forty-five-year trends in intra- and extrahepatic cholangiocarcinoma: sex- and race-based insights.

Background: A comprehensive review of 45-year trends in intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC) in the United States has not been published. Given their rising incidence, our study aimed to analyze trends in incidence and survival, comparing ICC and ECC.

Methods: We extracted a 45-year dataset (1975-2020) from the Surveillance, Epidemiology, and End Results database. Age-adjusted incidence rates were calculated using SEERStat®. Annual Percent Change (APC) was estimated via weighted least squares. Relative survival (1- and 5-year) was calculated using the Ederer II method and compared across sexes and races.

Results: A significant rise in ICC and ECC incidence was observed in both sexes (APC 3.71 for ICC vs. 6.16 for ECC; P<0.001). In females, ECC incidence increased more than ICC (APC 5.96 vs. 4.09, P<0.05), whereas males showed a fluctuating ECC trend and a steady ICC rise. Survival rates significantly improved across all races and sexes (P<0.05). ICC survival rose from 17.45% to 41.41% (1-year) and 2.83% to 10.99% (5-year), while ECC increased from 30.33% to 41.12% (1-year) and 5.96% to 10.44% (5-year). Among white and other-race females, ECC showed less improvement than ICC. Black individuals lacked statistically significant data.

Conclusions: Our study highlights disparities in ICC and ECC incidence, with higher rates in males, but better survival for ECC in males and ICC in females. The underrepresentation of Black individuals warrants further study to explore contributing factors such as risk, access to care, and treatment.