Pazopanib-Induced Liver Injury in Patients With Metastatic Renal Cell Carcinoma: A Report of Two Cases

We report two cases of pazopanib (PAZ)-induced liver injury in patients with metastatic renal cell carcinoma. The first patient was a 70-year-old female who was diagnosed with right renal cell carcinoma and showed tumor embolism in the inferior vena cava. PAZ was started but discontinued after about one month due to a grade four liver injury. The second patient was a 60-year-old male who was diagnosed with left renal cell carcinoma and suspected multiple lung metastases. PAZ was started following a laparoscopic left radical nephrectomy but was stopped after about a month due to a grade three liver injury. We analyzed the plasma PAZ concentrations for treatment evaluation. High plasma PAZ concentrations were observed in both patients after PAZ treatment began. Severe liver injury after PAZ administration may be associated with high plasma PAZ concentrations; hence, we should reduce PAZ dosage early. We also recommend monitoring plasma PAZ concentrations, if possible, so that physicians can either reduce the dosage or discontinue treatment to avoid further liver damage.