Long-lasting response with polycythemia to third-line axitinib treatment in metastatic renal cell carcinoma: Very rare case presentation

• Published in: Journal of oncology pharmacy practice Vol. 25; no. 6; pp. 1512 - 1515
• Main Authors: Dulgar, Ozgecan, Cil, Ibrahim, Zirtiloglu, Alisan, Tural, Deniz
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01-09-2019; Sage Publications Ltd
• Subjects: Clear cell-type renal cell carcinoma; Enzyme inhibitors; Erythropoietin; Hematology; Hemoglobin; Hypoxia; Hypoxia-inducible factors; Inactivation; Inhibitor drugs; Kidney cancer; Metastases; Metastasis; Mutation; Neoplasia; Polycythemia; Protein-tyrosine kinase; Survival; Targeted cancer therapy; Vascular endothelial growth factor; Vascular endothelial growth factor receptors; VHL protein; polycythemia; Axitinib; renal cell carcinoma; erythropoietin
• ISSN: 1078-1552; 1477-092X
• DOI: 10.1177/1078155218790342

Introduction
Clear cell renal cell carcinoma is characterized by mutation or inactivation of Von Hippel-Lindau suppressor gene. The mutation of Von Hippel-Lindau mechanism is associated with the upregulation of the hypoxia-inducible factor protein, inducing the overexpression of proteins including erythropoietin and vascular endothelial growth factor. Vascular endothelial growth factor receptor-targeted tyrosine kinase inhibitors are widely used in treatment of metastatic renal cell carcinoma. In paradoxical hematological effect with tyrosine kinase inhibitor therapies, hemoglobin level may be increased, but polycythemia requiring phlebotomy is very rare.
Case description
We present here a case of renal cell carcinoma who received successive treatment with sunitinib, everolimus, and axitinib. While he had a normal hemoglobin level with prior sunitinib treatment, on the sixth week of axitinib treatment, he developed polycythemia and treatment response was seen after axitinib-associated polycythemia.
Conclusion
Progression-free survival (PFS) was 30 months in our case with third-line treatment axitinib. Higher hemoglobin levels may be associated with longer survival. Polycythemia was the first response to treatment of axitinib in our patient. It may be an indicator of persistent treatment response.