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.
Author contributions:Study concept: Mukkamalla, Naseri, Armenio. Study design: Mukkamalla, Katz, Armenio. Data acquisition: Mukkamalla. Data analysis: Mukkamalla. Literature review: Mukkamalla, Naseri, Kim. Manuscript preparation: Mukkamalla, Naseri, Kim. Directed, reviewed and provided expert supervision: Katz, Armenio.Correspondence: Shiva Kumar R. Mukkamalla, MD, MPH, 30 Oaklawn Avenue, Apartment 303, Cranston, RI 02920. Email: firstname.lastname@example.org
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