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9 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
Essential thrombocythaemia is a slow blood cancer in which the marrow makes too many platelets. Most people need only aspirin and monitoring; those at higher risk of clots take a drug to lower the platelet count, usually hydroxyurea or interferon, with anagrelide in reserve.
Essential thrombocythaemia is a classical myeloproliferative neoplasm defined by a sustained platelet count above 450 x 10^9/L with a marrow full of large, mature megakaryocytes and no other explanation. About 60 percent carry JAK2 V617F, 20 to 25 percent a CALR mutation and 3 to 5 percent an MPL mutation; the rest are triple negative. Many people have no symptoms and are found on a routine blood count; others have headaches, visual disturbance, burning red hands and feet (erythromelalgia) or, at high platelet counts, paradoxical bleeding. Treatment is set by the IPSET-thrombosis score, which weighs age, prior clot, JAK2 status and cardiovascular risk: very low-risk patients may need nothing, low-risk patients take low-dose aspirin, and high-risk patients add cytoreduction with hydroxyurea or interferon, with anagrelide second line. The PT-1 trial showed hydroxyurea plus aspirin beats anagrelide plus aspirin on arterial clots and bleeding. Progression to myelofibrosis happens in a minority over decades and to acute leukaemia in a few percent. Bomedemstat, an LSD1 inhibitor, is in a phase 3 trial against hydroxyurea, and antibodies against mutant CALR are the first treatments aimed at the clone itself.
| Setting | Approach | Guideline |
|---|---|---|
| Diagnosis | Full blood count, JAK2, CALR and MPL testing, bone marrow biopsy to confirm ET and exclude prefibrotic myelofibrosis, and exclusion of reactive causes (iron deficiency, inflammation, infection, splenectomy). | not mapped |
| Very low and low risk | Observation alone in very low risk (under 60, no clot, JAK2-negative); low-dose aspirin for low risk and for anyone with microvascular symptoms, once acquired von Willebrand deficiency is excluded at very high platelet counts. | not mapped |
| High risk (over 60 with JAK2 or prior clot) | Cytoreduction to a platelet count under 400 x 10^9/L: hydroxyurea first line (PT-1), pegylated or ropeginterferon alfa-2b preferred under 60 and in pregnancy, anagrelide second line. | not mapped |
| Hydroxyurea resistance or intolerance | Switch to interferon or anagrelide; ruxolitinib did not beat best available therapy in MAJIC-ET but relieves symptoms. | not mapped |
| Progression to myelofibrosis | Managed as myelofibrosis: JAK inhibitors for spleen and symptoms, transplant for fit higher-risk patients. | not mapped |