Erythrocytosis, an increase in red blood cell mass, occurs in approximately 17.8% of patients with advanced thyroid cancer treated with antiangiogenic and targeted therapies.
RET inhibitors show the highest incidence of therapy-induced erythrocytosis, signaling a specific safety concern with these agents.
The hematologic abnormality is typically early in onset, recurrent, and manageable without significantly affecting survival or increasing vascular complications.
Current management includes dose adjustments and occasionally phlebotomy, but standardized guidelines are lacking.
