TY - JOUR A1 - Langbroek, Pepijn A1 - Polée, Marco A1 - de Graaf, Hiltje T1 - Escalating erythrocytosis after start of pazopanib-treatment in metastatic renal cell carcinoma Y1 - 2019/1/1 JF - Journal of Current Oncology JO - J Curr Oncol SP - 26 EP - 28 VL - 2 IS - 1 UR - http://www.https://journalofcurrentoncology.org//article.asp?issn=2589-8892;year=2019;volume=2;issue=1;spage=26;epage=28;aulast=Langbroek DO - 10.4103/JCO.JCO_24_18 N2 - Renal cell carcinoma accounts for 2% of adult malignancies in the Netherlands. Metastatic disease is often treated with vascular endothelial growth factor receptor tyrosine kinase inhibitors, such as pazopanib. This treatment is known to cause a slight increase in hemoglobin level during treatment. We present a patient who was diagnosed with metastatic renal cell carcinoma during analyses for erythrocytosis and who developed a further rise in hemoglobin level to 13.2 mmol/L 2 weeks after starting pazopanib treatment. Multiple phlebotomies were necessary before symptoms improved. Preexistent erythrocytosis should be considered as a risk factor for symptomatic erythrocytosis during pazopanib treatment and warrants timely laboratory follow-up and phlebotomies if indicated. ER -