Staging of intrahepatic cholangiocarcinoma

Purpose of review Staging of intrahepatic cholangiocarcinoma (ICC) has historically mirrored that for hepatocellular carcinoma, largely due to the fact that ICC has been an uncommon disease. This review summarizes recent developments related to prognostication in ICC that have allowed the development of a distinct Western staging system for this disease. Recent findings A large cancer registry study focused on identification of prognostic factors after resection of ICC with the aim of developing a distinct staging system for ICC. On the basis of this analysis and corroborative data from smaller institutional series, the American Joint Committee on Cancer (AJCC) 7th edition staging manual includes a distinct staging system for ICC that focuses on multiple tumors, vascular invasion, and lymph node metastasis. This system is simpler than the AJCC 6th edition staging yet preserves prognostic discrimination; the new system is also significantly superior to the Japanese staging system. Some evidence suggests that the number of lymph nodes involved by tumor may influence prognosis. Margin-negative resection is a major therapeutic determinant of outcome in ICC and should be pursued unless distant metastasis is present. Summary For the first time, a distinct staging system for ICC has been adopted by the AJCC. Understanding of prognostic factors in ICC remains incomplete but is improving. This field is in evolution, and further refinements to the staging of ICC are likely as more data emerge on this increasingly common malignancy.