The world-wide incidence of biliary tract cancer (BTC).

Abstract

585 Background: Existing epidemiologic research for BTC is limited to certain subtypes, eg gallbladder cancer (GBC), or combines BTC with liver cancer, and only reports regional statistics. Main sources for global BTC epidemiology (particularly anatomic sites) are literature reviews, which can be subject to limitations like inconsistent classification of subtypes, and varying standard population adjustment and comparison timeframes. Given the increasing incidence of BTC, it is critical to monitor global epidemiology to provide insight to public health management and clinical program development. Methods: We evaluated BTC incidence in 15 countries using the Cancer Incidence in Five Continents database Volume XI (CI5 XI) from the International Agency for Research on Cancer. Most CI5 XI registries cover data from 2008-12 with some variations. Incidence was examined by country, region, and anatomic site (extrahepatic cholangiocarcinoma, ECC; intrahepatic cholangiocarcinoma, ICC; GBC; ampulla of Vater cancer, AVC; 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). Results: The highest incidence of total BTC was in South Korea (SK; ASR = 3.00, SE = 0.02) and lowest in the UK (ASR = 0.66, SE = 0.01). Overall, BTC incidence was higher in Asian countries than Western, and in Asian-Americans than the general US population (ASR = 1.00, SE = 0.02 and 0.77, SE > 0.01, respectively). In Thailand, BTC incidence was higher in the North than South (ASR = 1.93, SE = 0.05 and 1.05, SE = 0.03, respectively). GBC and ECC are the top common subtypes in most countries reported. SK had the highest incidence of all subtypes, with ASR > 2 in GBC, ECC, and ICC. Outside of SK, GBC and ECC were most common in Japan (ASR = 1.93, SE = 0.02 and 2.66, SE = 0.03, respectively); ICC was most common in Thailand (ASR = 1.73, SE = 0.05) and high in France (ASR = 1.01, SE = 0.03). Conclusions: These registry data support past reports of higher BTC incidence in Asian vs Western countries as well as regional variation within countries. Data also suggests that high BTC rates in Asian populations may not be entirely geographical as Asian-Americans suffer a higher BTC incidence than the overall US population.