Related Experiment Video
Updated: Jan 16, 2026
Complete Laparoscopic Radical Resection of Perihilar Cholangiocarcinoma Type IIIb
Published on: January 17, 2025
A Case of Pathological Complete Response after "Conversion Surgery" for Initially Unresectable Locally Advanced
Yasunori Shirakawa1, Tomoaki Yoh1, Takashi Ito1
1Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan.
Introduction:
Intrahepatic cholangiocarcinoma (iCCA) is the second most common liver cancer and has a poor prognosis. Given the recent advancements in drug therapy, the topic of so-called "conversion surgery" in biliary tract cancer, including iCCA, is evolving; however, only a few cases have been reported.
Case Presentation:
A 50-year-old female was referred to our hospital for a liver tumor identified on abdominal ultrasonography. She was diagnosed with iCCA based on tumor biopsy. Due to extensive vascular and bile duct invasion, iCCA was initially considered unresectable. After 8 cycles of gemcitabine, cisplatin plus S-1 (GCS) therapy, CT revealed a partial response. Considering that microsatellite instability-high (MSI-H) was detected, we switched the regimen from GCS to pembrolizumab. However, after 1 cycle of pembrolizumab therapy, immune checkpoint inhibitor (ICI)-induced hepatitis was suspected; therefore, pembrolizumab therapy was suspended. GCS therapy was restarted, and after another 3 cycles, the iCCA was deemed resectable; therefore, conversion surgery was performed. Postoperative histopathological examination revealed a pathological complete response (pCR), and the patient remained alive more than 5 years postoperatively without recurrence or metastasis.
Conclusions:
We experienced a case of pCR induced by GCS chemotherapy and pembrolizumab monotherapy. Although the direct contribution of pembrolizumab remains unclear, a possible synergistic effect with GCS chemotherapy was suggested, particularly in MSI-H tumors.
