Epidemiology of intrahepatic, perihilar, and distal cholangiocarcinoma in the French population

Objectives The objective of this study was to investigate the differences between cholangiocarcinoma (CC) subtypes in terms of incidence rate, clinical presentation, management and survival by applying a stable anatomical classification in a population-based study. Patients and methods Cancer data for the period 2000-2012 were obtained from a specialized digestive cancer registry in the Department of Calvados, France. Patients' files were checked, and the diagnosis was verified by two hepatobiliary surgeons. This approach prevents classifying perihilar cholangiocarcinoma (PHCC) as intrahepatic cholangiocarcinoma (ICC), thereby allowing an accurate estimation of their respective epidemiological characteristics. Results A total of 320 patients with CC were included. ICC represented 41% (130), whereas PHCC and distal cholangiocarcinoma represented 36 (116) and 23% (74), respectively. The mean age at the time of diagnosis differed significantly between the three subtypes (P<0.05). ICC was discovered accidently more frequently than PHCC, which was associated significantly with clinical symptoms. No change in the incidence or survival rates of CC subtypes were noticed, except for PHCC, in which female individuals had a significantly shorter median and 5-year survival rate of 0% (P<0.05). Conclusion The frequency of PHCC is overestimated in the literature. The anatomical reclassification of CC subtypes shows the stability of their incidence and survival rates. Considering ICC and PHCC as two different entities implies the need to assign a specific topographic code for PHCC.