BACKGROUND: Klatskin tumor (KCC) is a rare type of tumor, with an annual incidence rate of no more than 1: 100 000. Because of its rarity, KCC is difficult to investigate. The present study provides new insights into KCC by a using public database.

MATERIAL AND METHODS: We used the Surveillance, Epidemiology, and End Results (SEER) database to conduct the analysis. Klatskin tumor patients were identified and compared with patients that had other kinds of cholangiocarcinomas (OCC). We identified differences between the 2 groups of patients and assessed tumor characteristics. We used Cox regression analysis to identify the prognostic indicators for KCC. The propensity score 1-to-1 matching method was used to compare the survival difference between KCC and OCC.

RESULTS: We extracted data on 26 137 patients diagnosed with cholangiocarcinomas between 1973 and 2014 from the SEER database: 1341 cases were diagnosed with KCC and 24 796 cases were diagnosed with OCC. The number of diagnoses has gradually increased in both groups. There were significant differences in pathology grades, T stage, N stage, M stage, and SEER historic stage between the KCC and OCC groups. Survival analysis showed that the OCC group had better survival compared to the KCC group, both in matched and unmatched cohorts. The Cox regression results showed that older age, higher M stages, and higher pathology grades were associated with worse prognosis for KCC patients.

CONCLUSIONS: KCC patients have worse survival compared to OCC patients. Older age, higher M stages, and higher pathology grades were associated with worse survival in KCC patients.

Keywords: Cholangiocarcinoma, Klatskin's Tumor, SEER Program, Aged, 80 and over, Incidence, propensity score, Proportional Hazards Models