Neoadjuvant chemotherapy followed by curative-intent surgery for perihilar cholangiocarcinoma based on its anatomical resectability classification and lymph node status.

<bold>Background: </bold>The prognosis of patients with perihilar cholangiocarcinoma have been unsatisfactory. We established new anatomical resectability classification for patients with localized perihilar cholangiocarcinoma and performed neoadjuvant chemotherapy followed by curative-intent surgery based on its resectability classification and lymph node status to improve prognosis. This study aimed to clarify the long-term outcomes and validation of our strategy.<bold>Methods: </bold>Between September 2010 and August 2018, 72 consecutive patients with perihilar cholangiocarcinoma were classified into three groups: Resectable (R = 29), Borderline resectable (BR = 23), and Locally advanced (LA = 20), based on the two factors of tumor vascular and biliary extension. R with clinically lymph node metastasis, BR, and LA patients received neoadjuvant chemotherapy using gemcitabine plus S-1.<bold>Results: </bold>Forty-seven patients (65.3%) received neoadjuvant chemotherapy: R in 8, BR in 21, and 18 in LA, respectively. Fifty-nine patients (68.1%) underwent curative-intent surgery: R in 26, BR in 17, and LA in 6. Five-year disease-specific survival was 31.5% (median survival time: 33.0 months): 50.3% (not reached) in R, 30.0% (31.4 months) in BR, and 16.5% (22.5 months) in LA, which were relatively stratified. Among 49 patients with resection, disease-specific survival was 43.8% (57.0 months): 57.6% (not reached) in R, 41.0% (52.4 months) in BR, and 0% (49.4 months) in LA, which were significantly good prognosis compared to 23 patients without resection (17.2 months). Multivariate analysis identified preoperative high carcinoembryonic antigen levels (more than 8.5 ng/ml) and pT4 as independent poor prognostic factor of patients with resection.<bold>Conclusion: </bold>Neoadjuvant chemotherapy based on resectability classification and lymph node status was feasible, and was considered efficacious in selected patients. [ABSTRACT FROM AUTHOR]