Case Report: a refractory case of CDKN2A/B loss metastatic intrahepatic cholangiocarcinoma achieving a partial response following treatment with palbociclib

Intrahepatic cholangiocarcinoma (ICC) is a highly aggressive and malignant subtype of biliary duct tumors. The poor prognosis of advanced ICC brings great challenges to clinical treatment, and the chemotherapy is still the standard first-line regimen. In recent years, the development of clinical research on targeted therapy for biliary tumors has brought new strategies for clinical treatment. Herein, we reported a 68-year-old patient with metastasis ICC harboring CDKN2A/B loss, who achieved a partial response (PR) for 6 months with CDK4/6 inhibitor palbociclib. No obvious side effects were observed. This case reveals the molecular characteristic of ICC patients who respond to palbociclib treatment and illustrates the importance of performing a multiple-gene panel test in ICC patients.