Assessment of global epidemiologic trends in incidence of biliary tract cancers (BTCs) showed higher BTC incidence in Asian versus Western countries as well as intraregional variations within countries, which is consistent with previous reports.
Given the increasing incidence of BTC and the need for accurate incidence estimates, a research effort was undertaken to evaluate the global epidemiologic trends in incidence of BTC; these results were presented at the American Society of Clinical Oncology (ASCO) 2020 Gastrointestinal Cancers Symposium.
BTC incidence was evaluated using the Cancer Incidence in Five Continents database Volume XI from the International Agency for Research on Cancer, which included data from 343 cancer registries in 65 countries from 2008 to 2012. Incidence was assessed by country, region, and anatomic site, including extrahepatic CCA, intrahepatic CCA, gallbladder cancer; ampulla of Vater cancer; and unspecified BTCs. Incidence was adjusted to standard world population and reported as age-standardized rate (ASR; per 100,000 person-years) with standard error (SE).
Total BTC incidence was evaluated in 22 countries, with variation noted by country and geographic region. Overall, BTC incidence was higher in Asian countries compared with Western countries. The incidence of BTC was highest in Chile (ASR, 14.35; SE, 0.037) and Republic of Korea (ASR, 10.37; SE, 0.06), and lowest in Vietnam (ASR, 1.25; SE, 0.08) and the United Kingdom (ASR, 2.29; SE, 0.02). In the United States, BTC incidence was higher among Asian-Americans (ASR, 3.45; SE, 0.06) than the general US population (ASR, 2.67; SE, 0.01). In Thailand, regional differences in BTC incidence were noted, with higher incidence in the north (ASR, 6.43; SE, 0.16) than the south (ASR, 3.53; SE, 0.10).
The most common BTC subtypes reported in most countries are gallbladder cancer and extrahepatic CCA, with ampulla of Vater cancer being the least common subtype. Overall, there was a higher incidence of gallbladder cancer in females, which was twice as high as males in most countries. By contrast, the incidence of extrahepatic CCA and intrahepatic CCA was twice as high in males in countries such as Bulgaria, France, Japan, Republic of Korea, and Thailand.
The investigators concluded that these results are consistent with previous registry data, showing higher BTC incidence in Asian versus Western countries as well as intraregional variations in countries.
Source: Wang H, et al. J Clin Oncol. 2020;38(4_suppl). Abstract 585.