TNM classification for perihilar cholangiocarcinoma: comparison between 5th and 6th editions of the AJCC/UICC staging system

A few investigators have evaluated the TNM classification for perihilar cholangiocarcinoma. The new sixth edition of the American Joint Committee on Cancer (AJCC)/Internal Union Against Cancer (UICC) staging system focuses on vascular invasion and regional lymph node metastasis.

For 166 patients with perihilar cholangiocarcinoma undergoing R0 resection, survival curves stratified according to TNM classifications were compared between fifth and sixth editions.

The previous T3 now is divided into T3 and T4. Most new pT4 patients had invasion of the portal bifurcation; their survival was poorer than that for new pT3 patients. The 5-, 10-, and 15-year survival rates were worse in the previous stage III than in the previous stage IVA, although the difference fell short of significance. The previous stage IVA (T3 Any NM0) is divided into new stages: IIA (T3N0M0), IIB (T1-3N1M0), and III (T4 Any NM0). All patients in stage III had invasion of the portal bifurcation. Survival was similar between stages IA, IB, and IIA, while patients with T4N0M0 tumors survived longer than those with T4N1M0 tumors and similarly to those with stage IIB tumors.

The sixth edition provided improved prediction of survival in patients with perihilar cholangiocarcinoma; for still better prediction, cancer invasion of the portal bifurcation and regional lymph node metastasis should be weighted equally.