A glimpse into the future of cholangiocarcinoma: Predicting the future incidence based on the current epidemiological data.

Abstract

616 Background: Cholangiocarcinoma (CCA) is an aggressive, heterogenous group of neoplasms that arise from the epithelial lining of bile ducts that have dismal poor prognosis. A recent epidemiological study in the United States demonstrated a steady increase in the incidence of cholangiocarcinoma from 2001 to 2017 with a predominant increase in the intrahepatic sub-type (iCCA). We sought to evaluate the future incidence of cholangiocarcinoma stratified based on the subtype, age, sex, and race, that could possibly help plan prevention, control, and treatment strategies for this cancer. Methods: We obtained histologically confirmed cases of cholangiocarcinoma (ICD-0-3 Site: C220, C21, and C240) from National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) 18 registries between 2000 to 2017 and predicted the incidence between the years 2018-2029. We applied age-period-cohort models to estimate future cholangiocarcinoma incidence rates (per 100, 000) and the estimated disease burden by multiplying incidence forecasts by corresponding US Census population projections. Results: A total of 12,737 and 8,395 patients with iCCA and extra-hepatic cholangiocarcinoma (eCCA) were included in the final analysis. The median age of iCCA cohort was 64 (range: 20-79) years and 46.4% were females whereas in eCCA the median age was 66 (range: 20-79) years and 43.8% were females. The overall observed age-adjusted incidence of iCCA between 2000-2017 was 1.07, which is predicted to increase to 2.13 by 2029 (99% increase) with a predominant increase in incidence rate observed in the age groups 70-79 and White males and females. Interestingly, incidence rate remained stable in Black and Asian males and in Asian females. Similarly, as compared to 2001-2017, the incidence of eCCA is projected to increase from 0.74 to 1.01 by 2029 (36.5% increase) with predominant increase noted in Black and Hispanic cohorts. In contrast, we noticed a relatively stable and decreasing incidence rate in White and Asian females, respectively. Conclusions: We predict an overall increased incidence of both iCCA and eCCA over the next decade especially in certain subgroups warranting the urgent need for preventive strategies. Further epidemiological studies are needed to determine the etiological factors contributing to predicted increase in incidence rate.