Risk factors and characteristics of young patients with the biliary tract carcinoma: results of a project study for biliary surgery by the Japanese Society of Hepato-Biliary-Pancreatic Surgery

Purpose: This study aimed to elucidate the characteristics of biliary tract carcinoma (BTC) in young patients. Methods: This is a nationwide multicenter, retrospective cohort study supervised by the Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS). Clinicopathological data of patients aged '50 years diagnosed with BTC from January 1997 to December 2011 were collected from 211 training institutes for highly advanced surgery registered by the JHBPS. Results: Data of 774 young patients aged '50 years were obtained from 102 institutes. Pancreaticobiliary maljunction (PBM) (10.6%) was most frequently associated with young BTC. However, organic solvents caused by printing or other occupations were only 2.5%. PBM was further associated with early onset of BTC and was noted in 38.9% of patients aged '30 years. Subgroup analysis revealed that the distributions of PBM, choledochal cysts, cholelithiasis, hepatitis B virus, and past history of cancer were significantly varied depending on the site of BTC. These results suggested that each site of BTC has a different mechanism for cancer development. Conclusion: Although the most frequent factor for young BTC patients was PBM, cancer-associated factors were dramatically different in each BTC site. These results might be useful to elucidate the etiology of young BTC patients.