• 58 patients were the control patients and were seen every two months
• WBC: 14.0, 45% Segs, 7% Bands, 15%Blasts
• Plts: 693K • PCR for BCR/ABL +
Objectives
• Establish the diagnostic criteria for Essential Thrombocythemia (ET)
63 yo male admitted with Appendicitis
• Diagnosed with Essential Thrombocythemiucil to keep platelet count less than <600,000K
Cortelazzo et. al. New England Journal of Medicine, April 1995
• Randomized trial comparing treatment with Hydroxurea to no myelosuppression in 114 Pts with ET at high risk for thrombosis.
– Arterial thrombus > venous thrombus – Arterial thrombi more common with
smoking, hypertension, coronary artery disease, diabetes mellitus
What is the evidence supporting treatment for ET?
• Discuss the natural history of ET • Discuss the evidence supporting the
treatment of ET • Discuss acute Leukemia following ET
Diagnostic Criteria for ET
Essential Thrombocythemia Followed by Acute Leukemia
Does therapy lead to leukemic transition or is it a failure of accurate diagnosis?
Joel Saltzman MD Hematology/Oncology Fellow Metro Health Medical Center
• 1999 diagnosed with AML; cytogenetics normal
• Offered induction therapy with 7+3. Pt refused. Continued on Chlorambucil.
• Stable AML x 2 years
WS labs.
– Trisomy 8 most common abnormality
Clinical Course
• No change in life expectancy • Majority of patients have course
complicated by thrombosis and hemorrhage.
Pathophysiology
• Clonal disorder of a multipotent stem cell which gives rise to erythrocytic, granulocytic, and megakaryocytic series
• Cytogenetic abnormalities demonstrated in <25% of patients
• Platelet count kept below 600,000 in the treatment group
What defined the High Risk Patient?
• Age > 60 years (55%) • Previous history of thrombosis (15%) • Both (30%) • Platelet Count >1,500,000(excluded
from randomization because of high risk of bleeding/thrombosis)
Methods
• 56 pts randomly assigned to hydroxyurea group. Seen every two weeks until plt count <600,000. Starting dose of hydroxyurea 15mg/kg/day.
myelodysplastic syndrome • No cause for reactive thrombocytosis
Presenting Features
• Vasomotor symptoms: Erythromelagia • Headache, dizziness, visual
disturbances • Thrombosis or bleeding • More common in women • Splenomegaly • Asymptomatic
• Platelet count >600,000 • Hematocrit,40 or normal RBC mass • Normal serum ferritin and MCV • No Philadelphia Chromosome or bcr/abl gene
rearrangement • Absence of collagen Fibrosis on bone marrow • No cytogenetic or morphologic evidence for a