Van Dyke AL, et al. - In the US, the demographic disparities in biliary tract cancer incidence rates and time trends by anatomic site were analyzed via this investigation utilizing data from North American Association of Central Cancer Registries. Women and all racial/ethnic groups demonstrated a decline in the gallbladder cancer (GBC) incidence rates, with the exception of non-Hispanic blacks, who had increased rates. They saw increased GBC rates in 18- to 44-year-olds, while reduced rates were seen among people 45 years old or older. Compared to older people, younger people showed larger differences in GBC incidence by sex and race/ethnicity. A steady increase in intrahepatic cholangiocarcinoma and extrahepatic cholangiocarcinoma rates was evident during this time across sex and racial/ethnic groups. Although among younger adults but not older adults, increased ampulla of Vater cancer incidence rates were reported, no difference was found in sex and racial/ethnic incidence rate ratios by age.