Liver resection for intrahepatic cholangiocarcinoma in AJCC‑stage Ⅳ: An evaluation of the survival benefit and prognostic accuracy of current AJCC staging system on N and M classification.

Intrahepatic cholangiocarcinoma (ICC) is usually confirmed in advanced stage at the time of diagnosis or after surgical exploration, however, indication of surgical treatment is usually controversial for ICC in advanced stages. This retrospective study aims to evaluate clinical value of surgery for such tumors, in order to identify the appropriate patients who will benefit from surgery, and to evaluate the prognostic accuracy of the current staging system for advanced ICC. From January 2007 to December 2011, 387 consecutive surgically treated patients with ICC in AJCC‑stage Ⅳ were evaluated. Survival was compared among different patients grouped by different elements of AJCC staging system. The prognostic importance of extent of lymph node (LN) metastasis relative to the AJCC N and M classification system was assessed. Our data showed that survival was much better for patients in AJCC‑stage ⅣA group (median survival time, MST, 9.0 months) than in AJCC‑stage ⅣB group (MST, 5.0 months) (P<0.001). While in AJCC‑stage ⅣB group, survival for patients in AnyTN2‑3M0 subgroup (MST, 9.0 months) was much better than in AnyTN0M1 subgroup (MST, 3.0 months); and better than in AnyTN2‑3M1 subgroup (MST, 4.0 months) (P<0.001). Overall, R0 and R1 liver resection should be indicated for patients in AJCC‑stage ⅣA group and AnyTN2‑3M0 subgroup in AJCC‑stage ⅣB group, as patients in these groups will benefit from surgery with relatively better survival. Staging of advanced ICC by N2‑3 instead of M1 for extended LN metastasis classification is superior in comparison with the AJCC staging system.