Sex-Specific and Race/Ethnicity-Specific Disparities in Cancer Incidence and Prevalence Among Adults With Cholangiocarcinoma in the U.S.: An Analysis of the 2000-2011 Surveillance, Epidemiology, and End Results Registry

Abstract

Introduction: Cholangiocarcinoma (CCA) is a rare, but lethal malignancy of the biliary tree with poor long-term survival outcomes. While the worldwide incidence of intrahepatic cholangiocarcinoma (ICC) has been increasing, several studies report a decreasing incidence of extrahepatic cholangiocarcinoma. However, it is not clear if sex-specific or race/ethnicity-specific disparities in CCA incidence exist. The aim of our study was to evaluate age-specific, sex-specific, and race/ethnicity-specific disparities in the incidence and disease burden of CCA. Methods: Using population based cancer registry data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program, we retrospectively evaluated all U.S. adults (age > 20) with cholangiocarcinoma. Sex-specific, race/ethnicity-specific, and age-specific incidence and prevalence of cholangiocarcinoma were evaluated from 2000 to 2011. Incidence rates were age-adjusted to year 2000 population and stratified by ICC and ECC. Results: From 2000-2011, there were a total of 11,296 patients with ICC and 8,672 patients with ECC. The overall incidence of ICC was significantly higher than the incidence of ECC (1.6 vs. 1.3 per 100,000/year, p < 0.01). Among all race/ethnic groups and among both ICC and ECC, Asians had the highest cancer incidence. When stratified by age, CCA incidence increased with age among all groups; however, the rising incidence was most rapid among Asians. For example, among patients age 80 and over, the incidence of ICC among Asians was nearly twice the incidence among non-Hispanic whites (13.8 vs. 7.2 per 100,000/y, p < 0.01). Overall, CCA incidence was higher among men compared to women, and with increasing age, this sex-specific disparity was more pronounced. For example, among patients age 80 and over, the incidence of ICC was 9.8 per 100,000/year among men and 6.9 per 100,000/year among women. Conclusion: Among adults with CCA in the U.S., increasing age was associated with increasing incidence of CCA. In addition, sex-specific and race/ethnicity-specific disparities were seen with the highest incidence of CCA among men and among Asians.Figure 1