Case Report: Conversion therapy for initially unresectable intrahepatic cholangiocarcinoma.

Background: Intrahepatic Cholangiocarcinoma (ICC) is a highly malignant tumor originating from the intrahepatic biliary epithelium, characterized by strong invasiveness and poor prognosis. For patients with unresectable advanced ICC, the current first-line standard treatment is the gemcitabine plus cisplatin regimen, but its efficacy is limited. In recent years, with the exploration of immunotherapy, targeted therapy, and various combination treatment modalities, new directions have been provided for the treatment of advanced ICC. Case presentation: This article reports a case of a patient with initially unresectable ICC who underwent conversion therapy with percutaneous portal vein embolization (PVE) combined with surufatinib (a multi-kinase inhibitor targeting VEGFR, FGFR, and CSF-1R), sintilimab (a PD-1 inhibitor), and the FOLFOX regimen (leucovorin, fluorouracil, and oxaliplatin). This approach successfully enabled radical liver resection and resulted in long-term disease-free survival. The patient was a 71-year-old male diagnosed via enhanced CT and MRI with a large liver mass accompanied by portal vein tumor thrombus. Pathological confirmation by needle biopsy confirmed intrahepatic cholangiocarcinoma. Due to extensive tumor invasion and insufficient future liver remnant (FLR), the tumor was assessed as unresectable. The treatment team adopted a multimodal conversion strategy: first performing PVE to promote compensatory hyperplasia of the FLR; subsequently administering 4 cycles of surufatinib, sintilimab combined with FOLFOX chemotherapy. Post-treatment imaging evaluation showed significant tumor shrinkage, along with an increase in FLR volume, meeting the criteria for safe radical surgery. Two weeks after stopping medication, the patient underwent right hemihepatectomy, caudate lobe resection, cholecystectomy, hepatoduodenal lymph node dissection and inferior vena cava repair. The patient recovered well postoperatively. At the last follow-up, he had achieved 28 months of disease-free survival with no evidence of local recurrence or distant metastasis. Conclusion: For initially unresectable ICC, conversion therapy with PVE combined with surufatinib, sintilimab, and the FOLFOX regimen can significantly increase the tumor resection rate and achieve long-term survival. This strategy combines high anti-tumor efficacy with clinical feasibility, providing a new approach for the conversion therapy of advanced ICC. Further larger sample studies are needed in the future to verify its efficacy and safety.