The first 60 days: Essential thrombocythaemia (ET)

Below, week by week, is what OnCo's record of Essential thrombocythaemia (ET) says about the first two months: the order is typical, the timing is yours to ask about. 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. Sections appear only where the record has something to say. Orientation, not medical advice.

Weeks 1 to 2

What happens now

Staging tests establish exactly what and where the cancer is. Everything else follows from the answers.

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).
JAK2 JAK2 V617F Myeloproliferative neoplasms (PV, ET, myelofibrosis)

Biomarkers your report may list

Platelet count above 450 x 10^9/L JAK2 V617F, CALR exon 9 and MPL W515 mutations IPSET-thrombosis score (age over 60, prior thrombosis, JAK2 V617F, cardiovascular risk factors)Marrow histology to exclude prefibrotic myelofibrosis Acquired von Willebrand deficiency at platelet counts above 1,000 x 10^9/L (bleeding risk with aspirin)

Ask which of these were tested and what the results were; see the report reader for what each value means.

Weeks 1 to 3

Who is on your team

These specialties appear in the standard of care for this cancer. In most centres they meet weekly as a tumour board to agree each plan; you can ask when yours was discussed and what was decided.

A second opinion from a centre that treats many similar cases is normal, not rude; the standard of care tells you what to compare it against.

Weeks 2 to 6

Decisions coming up

Each row is a setting from the standard of care, in the order it usually arises. Not all will apply to you; your stage and biomarkers decide which do. The guideline grade, where recorded, says how strong the evidence is.

1.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.
Aspirin Erythromelalgia
2.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.
Hydroxyurea (hydroxycarbamide)PT-1 (Primary Thrombocythaemia 1)Ropeginterferon alfa-2b Anagrelide
3.Progression to myelofibrosis
Managed as myelofibrosis: JAK inhibitors for spleen and symptoms, transplant for fit higher-risk patients.
Myeloproliferative neoplasms (PV, ET, myelofibrosis)Post-PV myelofibrosis (spent phase)Ruxolitinib
4.Hydroxyurea resistance or intolerance
Switch to interferon or anagrelide; ruxolitinib did not beat best available therapy in MAJIC-ET but relieves symptoms.
Anagrelide Ruxolitinib MAJIC-ET

Every visit

Questions to ask at each visit

Generated from this cancer's standard of care, biomarkers and open problems. Take the group that matches where you are. To tick, add your own and print, open the one-page appointment sheet.

Newly diagnosed

What is my exact diagnosis, stage, and grade, and which tests established them?Everything else follows from an accurate stage and subtype.
Which biomarkers have been tested on my tumour (for example Platelet count above 450 x 10^9/L, JAK2 V617F, CALR exon 9 and MPL W515 mutations, IPSET-thrombosis score, Marrow histology to exclude prefibrotic myelofibrosis, Acquired von Willebrand deficiency at platelet counts above 1,000 x 10^9/L), and what were the results?These results decide eligibility for targeted therapy, immunotherapy, and trials.
Which subtype is my cancer, and does that change the recommended treatment?Recognised subtypes for this cancer include JAK2 V617F-mutated, CALR-mutated, MPL-mutated.
Is germline (inherited) genetic testing recommended for me or my family?Inherited variants can change treatment and matter for relatives.

Diagnosis

For my situation (diagnosis), which of the standard options do you recommend and why?Guideline options include: 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).

Very low and low risk

For my situation (very low and low risk), which of the standard options do you recommend and why?Guideline options include: 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.
Am I a candidate for Aspirin, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.

High risk (over 60 with JAK2 or prior clot)

For my situation (high risk (over 60 with jak2 or prior clot)), which of the standard options do you recommend and why?Guideline options include: 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.
Am I a candidate for Hydroxyurea (hydroxycarbamide), Ropeginterferon alfa-2b, Anagrelide, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
How do the results of PT-1 (Primary Thrombocythaemia 1) apply to someone like me?Trial populations differ from individual patients; ask how closely you match.

Hydroxyurea resistance or intolerance

For my situation (hydroxyurea resistance or intolerance), which of the standard options do you recommend and why?Guideline options include: Switch to interferon or anagrelide; ruxolitinib did not beat best available therapy in MAJIC-ET but relieves symptoms.
Am I a candidate for Anagrelide, Ruxolitinib, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
How do the results of MAJIC-ET apply to someone like me?Trial populations differ from individual patients; ask how closely you match.

Progression to myelofibrosis

For my situation (progression to myelofibrosis), which of the standard options do you recommend and why?Guideline options include: Managed as myelofibrosis: JAK inhibitors for spleen and symptoms, transplant for fit higher-risk patients.
Am I a candidate for Ruxolitinib, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.

Any stage

Are there clinical trials I could join, for example of Bomedemstat, Ropeginterferon alfa-2b?Trials are how the next standard of care is set; asking early keeps options open.
Would a second opinion at a high-volume centre change anything, and can you help arrange it?Rare or high-stakes decisions benefit from a centre that treats many similar patients.
What supportive care (symptom control, nutrition, exercise, mental health, financial help) is available from the start?Supportive care improves quality of life and helps patients complete treatment.
I read that “No treatment has been shown to prevent progression to myelofibrosis or leukaemia”. How does that affect my plan?Open problems are where trials and second opinions matter most.
I read that “Very low-risk patients receive nothing and low-risk patients aspirin, but the evidence for aspirin in CALR-mutated low-risk disease is thin and bleeding may outweigh benefit”. How does that affect my plan?Open problems are where trials and second opinions matter most.

Weeks 3 to 8

Trials to ask about

Trials open now for this cancer in OnCo, largest phase first. Joining a trial is a decision like any other: ask what the comparison arm is, whether a placebo is used, and what happens if you leave. The cancer page searches ClinicalTrials.gov live for more.

From day one

Help that costs nothing

Much of what helps in the first weeks is free if you know to ask: testing, helplines, rides and lodging, second opinions, trial travel.

Any time

What to read next

Words this page and the cancer page use

IPSET-thrombosis score (essential thrombocythaemia): Essential thrombocythaemia rarely shortens life, so treatment is about preventing clots: the IPSET-thrombosis score combines age over 60, a previous clot and the JAK2 mutation to sort patients into very low, low, intermediate and high risk, and only the higher groups take a platelet-lowering drug.
MPN driver mutations (JAK2 V617F, CALR, MPL) and allele burden: Almost every polycythaemia vera and most essential thrombocythaemia and myelofibrosis carry one of three mutations (JAK2 V617F, CALR or MPL) that jam the growth signal on; finding one confirms the diagnosis is a true blood cancer rather than a reaction to something else, and the mutation type and how much of the blood carries it shape the risk of clots and progression.
Erythromelalgia: Burning pain, redness and heat in the hands or feet, brought on by warmth.
JAK2 V617F: A single letter change in the JAK2 gene that jams the growth signal for blood cells in the on position.
Post-PV myelofibrosis (spent phase): The late stage some people with polycythaemia vera reach after many years, when the marrow scars over, the red count falls and the spleen swells.

Every term links to the glossary.