Trends in Incidence and Factors Affecting Survival of Patients With Cholangiocarcinoma in the United States.

Background: Cholangiocarcinoma (CCA) includes cancers arising from the intrahepatic and extrahepatic bile ducts. The etiology and pathogenesis of CCA remain poorly understood. This is the first study investigating both incidence patterns of CCA from 1973 through 2012 and demographic, clinical, and treatment variables affecting survival of patients with CCA. Patients and Methods: Using the SEER database, age-adjusted incidence rates were evaluated from 1973-2012 using SEER*Stat software. A retrospective cohort of 26,994 patients diagnosed with CCA from 1973-2008 was identified for survival analysis. Cox proportional hazards models were used to perform multivariate survival analysis. Results: Overall incidence of CCA increased by 65% from 1973-2012. Extrahepatic CCA (ECC) remained more common than intrahepatic CCA (ICC), whereas the incidence rates for ICC increased by 350% compared with a 20% increase seen with ECC. Men belonging to non-African American and non-Caucasian ethnicities had the highest incidence rates of CCA. This trend persisted throughout the study period, although African Americans and Caucasians saw 50% and 59% increases in incidence rates, respectively, compared with a 9% increase among other races. Median overall survival (OS) was 8 months in patients with ECC compared with 4 months in those with ICC. Our survival analysis found Hispanic women to have the best 5-year survival outcome (P<.0001). OS diminished with age (P<.0001), and ECC had better survival outcomes compared with ICC (P<.0001). Patients who were married, were nonsmokers, belonged to a higher income class, and underwent surgery had better survival outcomes compared with others (P<.0001). Conclusions: This is the most up-to-date study of CCA from the SEER registry that shows temporal patterns of increasing incidence of CCA across different races, sexes, and ethnicities. We identified age, sex, race, marital status, income, smoking status, anatomic location of CCA, tumor grade, tumor stage, radiation, and surgery as independent prognostic factors for OS in patients with CCA.

Estimation of the Incidence of Hepatocellular Carcinoma and Cholangiocarcinoma in Songkhla, Thailand, 1989-2013, Using Multiple Imputation Method.

PURPOSE: Histological specimens are not required for diagnosis of liver and bile duct (LBD) cancer, resulting in a high percentage of unknown histologies. We compared estimates of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) incidences by imputing these unknown histologies. MATERIALS AND METHODS: A retrospective study was conducted using data from the Songkhla Cancer Registry, southern Thailand, from 1989 to 2013. Multivariate imputation by chained equations (mice) was used in re-classification of the unknown histologies. Age-standardized rates (ASR) of HCC and CCA by sex were calculated and the trends were compared. RESULTS: Of 2,387 LBD cases, 61% had unknown histology. After imputation, the ASR of HCC in males during 1989 to 2007 increased from 4 to 10 per 100,000 and then decreased after 2007. The ASR of CCA increased from 2 to 5.5 per 100,000, and the ASR of HCC in females decreased from 1.5 in 2009 to 1.3 in 2013 and that of CCA increased from less than 1 to 1.9 per 100,000 by 2013. RESULTS: of complete case analysis showed somewhat similar, although less dramatic, trends. CONCLUSION: In Songkhla, the incidence of CCA appears to be stable after increasing for 20 years whereas the incidence of HCC is now declining. The decline in incidence of HCC among males since 2007 is probably due to implementation of the hepatitis B virus vaccine in the 1990s. The rise in incidence of CCA is a concern and highlights the need for case control studies to elucidate the risk factors.