Table 3.

Risk stratification and preferred treatment options for essential thrombocytosis (adapted from [6])

	History of thrombosis	Age > 60 years	JAK2 mutation	CV-RF−	CV-RF+
Very low-risk disease	No	No	No	None	ASA
Low-risk disease	No	No	Yes	ASA q.d.—b.i. d.	ASA b.i. d.
Intermediate-risk disease	No	Yes	No	ASA (± HU)	HU + ASA
High-risk disease	No	Yes	Yes	HU + ASA b.i. d.	HU + ASA b.i. d.
High-risk disease	Yes, arterial	No (or yes)	No (or yes)	HU + ASA b.i. d.	HU + ASA b.i. d.
High-risk disease	Yes, venous	No (or yes)	No	HU + s-ac	HU + s-ac + ASA
High-risk disease	Yes, venous	No (or yes)	Yes	HU + s-ac + ASA b.i. d.	HU + s-ac + ASA b.i. d.

NB Treatment with cytoreductive therapy should be avoided in the presence of extreme thrombocytosis (platelets > 1500 × 109/l) and acquired von Willebrand syndrome

CV-RF cardiovascular risk factors − (absent), + (present), ASA acetylsalicylic acid, HU hydroxyurea, s‑ac Systemic anticoagulation, b.i.d. twice a day