Epidemiology of cholangiocarcinoma in Florida, and differences in risk factors between intra- and extra-hepatic cholangiocarcinoma.

Abstract

e16329 Background: Albeit rare, cholangiocarcinoma (CC) is a poorly understood, highly fatal cancer with an incidence rate of less than 2.5 per 100,000 people. For most cases of CC, causes are not known. Here, we use population-based data from the diverse state of Florida to study the most recent incidence rates and trends for intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC) and measure the prevalence of potential risk factors and preexisting conditions associated with liver cancer including biliary conditions, diabetes, obesity and dyslipidemia, hypertension, smoking, chronic hepatitis C (HCV) and hepatitis B (HBV) infections, alcohol-related disease, and auto-immunes diseases. Methods: We used the Florida Cancer Registry Data on all cases of cholangiocarcinoma (N = 5,096) diagnosed during 2010–2018 (2,930 intra-hepatic, 2,166 extra-hepatic). Data were linked with two other data sources: the Agency for Healthcare Administration and the Department of Viral Hepatitis. Age-adjusted rates by sex were computed, incidence trends using Joinpoint regression and 5-year age-adjusted survival, using lifetable methods, were estimated. Differences in prevalence of risk factors were tested using chi-square tests. Results: Both ICC rates, 1.7 (per 100,000) for males and 1.3 for females, and ECC rates, 1.0 in males and 0.7 in females are relatively low. ICC is currently the fastest increasing cancer at a rate of +7.2% per year in males and +6.5% in females, while ECC trends remain stable. The 5-year survival was 11.0% for ICC (95%CI: 9.2-12.8) and 12.9% (95%CI: 10.5-15.3) for ECC. Overall, conditions such as diabetes type 2 (29%), obesity and dyslipidemia (41%), and hypertension (61%) were highly but equally prevalent in both ICC and ECC. The presence of non-alcohol related cirrhosis (6.0% vs 2.8% for ICC and ECC, respectively), chronic HCV infection (6.6%, 2.0%), and smoking (52.7%, 48.5%) were significantly more prevalent in ICC, while cholangitis of any type (13.5%,26.0%), chronic pancreatitis, auto-immune diseases (all. Conclusions: Currently, ICC is the most rapidly increasing cancer in the US; though, the extent to which better recognition of ICC plays a role in this trend is unknown. ICC and ECC show similarities, but also, differences in the prevalence of specific risk factors and preexisting conditions. The commonly held perception that the increase in metabolic causes (diabetes and obesity), similarly present in both ICC and ECC, are responsible for the current trends is partially challenged by the stable trends in ECC. Given its dismal prognosis, cholangiocarcinoma, especially ICC, requires further research. Funding: This work was supported by Bankhead Coley Grant #20B16 from the Biomedical Research Program of the Department of Health State of Florida.