초록
The American Joint Committee on Cancer (AJCC) Cancer staging system has been revised every 6~8 years since the first edition of the cancer staging system was introduced in 1977. The latest edition, the $7^{th}$, was published in 2009 and has been used since January, 2010. In case of gallbladder cancer, perihilar cancer and distal common bile duct cancer, there are several changes compared to the $6^{th}$ edition (revised in 2002). In gallbladder cancer, there is no difference in lymph node location from the $6^{th}$ edition, but in the $7^{th}$ edition disease is divided into hilar nodes and other regional lymph nodes. This has been reclassified in terms of the possibility of surgical resection and patient outcome. In perihilar cancer, we had to follow cancer staging for extrahepatic bile duct cancer because there was no classification previously; but now a new staging guideline has been introduced. There is no difference from the $6^{th}$ edition in cancer staging of the distal common bile duct. However, the classification of the primary site has changed according to involvement of the celiac axis or superior mesenteric artery in invasion of adjacent organs. Explanations for the differences between the $5^{th}$, $6^{th}$ and $7^{th}$ editions are introduced and the helpfulness of the new system in clinical applications is examined.