Successful Control of Carcinoma of Unknown Primary with Axitinib, a Novel Molecular-Targeted Agent: A Case Report

Carcinoma of unknown primary (CUP) is a common malignancy. In view of the poor prognosis of CUP, more effective therapy is needed. A 47-year-old man with CUP affecting the bone visited our institution. Treatment with heavy ion radiotherapy, cytotoxic chemotherapy, and resection of the bone tumor conferred neither control of the tumor nor the patient's symptoms such as tumor fever and bone pain. The bone biopsy at hemipelvectomy suggested undifferentiated adenocarcinoma with some features of clear cell carcinoma, although no lesions were detected in the kidneys. Based on the pathological diagnosis, treatment with sunitinib or everolimus was administered but resulted in progressive disease. However, axitinib showed favorable effects, controlling tumor progression and palliating his symptoms. To our knowledge, this is the first case of successful control of CUP with axitinib.