Gross pathological classification of peripheral cholangiocarcinoma determines the efficacy of hepatectomy.

BACKGROUND

Peripheral cholangiocarcinoma (PCC) can be grossly classified as mass-forming (MF), periductal-infiltrating (PI), and intraductal papillary (IP) types. IP-PCC should be distinguished from other types of PCC because patients with IP-PCC have a more favorable prognosis. We hypothesized that gross pathological classification of non-IP-PCC could determine the efficacy of hepatectomy.

METHODS

We retrospectively reviewed 224 histologically proven PCCs (including 172 PCCs from patients having non-IP type tumors) from patients who underwent hepatectomy between 1977 and 2007. Non-IP-PCCs were further classified as MF, MF mixed with PI (MF-PI), and PI for comparison.

RESULTS

Of the 224 patients with PCC, 52 had IP-PCC (23.2 %), and 172 had non-IP-PCC (76.8 %). One hundred one of the 172 non-IP-PCC patients had a curative resection (curative resection rate 58.7 %). The follow-up duration ranged from 1.1 to 193.1 months (median 13.4 months). Overall survival (OS) rates for the non-IP-PCC patients at 1 and 5 years were 58.4 and 15.1 %, respectively. Absence of symptoms, lower alkaline phosphatase levels, normal carcinoembryonic antigen (CEA), and presence of MF-type PCC independently and favorably affected OS for the non-IP-PCC patients following hepatectomy. Independent factors favorably predicting OS for the MF-PCC patients were the absence of symptoms, hepatolithiasis, normal CEA levels, successful curative hepatectomy, and negative lymph node metastasis, while for the MF-PI-PCC patients following hepatectomy, one independent factor, successful curative hepatectomy, favorably predicted OS. For the PI-PCC patients, the independent factors favorably predicting OS were normal albumin levels and negative lymph node metastasis.

CONCLUSIONS

It is important to correctly differentiate between the gross pathological classifications of non-IP-PCC because of their distinct characteristics and outcomes following hepatectomy. Correct gross pathological classification is essential for further translational investigations.