Polycythaemia Vera (PV)
Haematological Pathway
for
South Wales Cancer Network
Document Control Sheet
Organisation
Specialty/Project
Document Title
Document Number
South Wales Cancer Network
Haematological Site Specific Group
Polycythaemia Vera Haematological Pathway
05/004
Version
2.0
Approved by
South Wales Haematology
Cancer Network Group
Author/s
Dr S Knapper
Ratified by
Approval date
Date of next review
19/03/15
19/03/16
Dr N Abdelrahman
Dr C Jenkins
Dr C Fegan
Dr W Ingram
Polycythaemia Vera (PV)
NSAG Patient Care Pathway
Demographics
- Estimated incidence of PV is 0.7-2.6 per 100,000 per year
- Rises with age, median age for diagnosis is 60yrs. Slight male predominance
(1-2:1)
Diagnosis
- Elevated haemoglobin / haematocrit has a wide differential diagnosis
including: polycythaemia vera (PV)
secondary causes of polycythaemia (eg.chronic hypoxia, EPOsecreting tumours) ‘apparent polycythaemia’ resulting from
plasma depletion.
- The threshold for investigation of individual patients will vary according to
prior history of arterial or venous thrombosis, presence of thrombotic risk
factors and associated symptoms. In general, patients with persistently
raised haematocrit (>0.52 males, >0.48 females) should be investigated.
Diagnostic tests
- Initial screen: FBC, Blood film, JAK2 V617F PCR, ferritin, renal and liver
biochemistry
- If initial JAK2 mutation testing is negative and no obvious secondary cause is
apparent, red cell mass / blood volume studies should be performed to
confirm whether an absolute erythrocytosis (‘true polycythaemia’ is present).
This investigation is currently available at University Hospital of Wales,
Cardiff and Singleton Hospital, Swansea.
- In JAK2 V617F negative patients in whom raised cell mass (>25% above
predicted) is confirmed, the following tests are appropriate:
Arterial blood gases
Abdominal ultrasound
Serum erythropoietin (EPO) level
Bone marrow aspirate and trephine biopsy (including cytogenetic
analysis)
JAK2 exon 12 mutation screening (MF McMullin-Belfast or N CrossSalisbury)
Polycythaemia Vera (PV) Pathway
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BCSH diagnostic criteria for polycythaemia vera
JAK2-Postitive Polycythaemia Vera: (A1 and A2 need to be present)
A1: High haematocrit (>0.52 M, >0.48 F) OR raised red cell mass (>25% above
predicted)
A2: JAK2 mutation (V617F or exon 12)
JAK2- Negative Polycythaemia Vera: (A1+A2+A3+either another A or two
B criteria)
A1: Raised red cell mass (>25% above predicted) OR haematocrit >0.60 M,
>0.56 F)
A2: Absence of mutation in JAK2
A3: No cause of secondary erythrocytosis
A4: Palpable splenomegaly
A5: Presence of acquired genetic abnormality (excluding BCR-ABL) in
haematopoietic cells
B1: Thrombocytosis (platelet count >450×109/l)
B2: Neutrophil leucocytosis (neutrophil count > 10×109/l non-smokers;
>12.5×109/l smokers)
B3: Radiological evidence of splenomegaly
B4: Low serum erythropoietin or endogenous erythroid colony formation
Staging and Prognostication
- There is no formal staging system in PV
- High risk features: age>60
previous documented thrombosis, migraine,
erythromelalgia
‘significant splenomegaly’ (>5cm palpable or
symptomatic)
platelet count >1000x109/l
diabetes or hypertension requiring pharmacological
therapy
Information Required at MDT:
-ICD10 v 4 morphology code (M9950/3)
Treatment
The aims of treatment of PV are to: reduce the risk of thrombosis and
haemorrhage, minimize the risk of transformation to AML or myelofibrosis, and to
manage disease-related symptoms and complications
General measures for all patients:
- Venesection to maintain the haematocrit at less than 0.45
- Aspirin (75 mg daily) for all patients unless contraindicated
- Aggressive management of cardiovascular risk factors: hypertension,
smoking, diabetes, cholesterol
Polycythaemia Vera (PV) Pathway
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Cytoreductive therapy:
- Should be considered if : Poor tolerance of venesection
Symptomatic or progressive splenomegaly
Severe symptoms: weight loss,sweats, pruritus
Thrombocytosis
-
For those requiring cytoreductive therapy the choice of agent will be
influenced by age (and whether patient or partner contemplating pregnancy),
side effect profile and potential leukaemogenicity. In general:
<40 years old: first line interferon, second line hydroxycarbamide
40–75 years old: first line hydroxycarbamide, second line interferon
>75 years old: first line hydroxycarbamide, second line 32P /
intermittent low dose busulphan or pipobroman
(addition of anagrelide may be considered for control of
thrombocytosis)
MAJIC study: High risk PV patients who are unable to tolerate hydroxycarbamide
or in whom hydroxycarbamide is ineffective may be eligible for entry into MAJIC (a
randomized comparison of the JAK inhibitor Ruxolitinib with ‘best alternative
therapy’). For information contact Dr Steve Knapper.
Monitoring
- Regular haematology outpatient clinic follow-up to monitor full blood count,
disease symptoms / complications and treatment toxicity.
- Patients receiving anagrelide should be offered 3-yearly bone marrow
trephine biopsy to monitor for early evidence of myelofibrotic transformation
Discharge
- PV patients will generally require lifelong haematology clinic follow-up
References
Guidelines for the diagnosis, investigation and management of
polycythaemia/erythrocytosis McMullin MF et al. British Journal of Haematology
2005:130:174–195.
Amendment to the guideline for diagnosis and investigation of
polycythaemia/erythrocytosis. McMullin MF et al. British Journal of Haematology
2007:138:821–82
WHO Classification of tumours of haematopoietic and lymphoid tissues (edited by
Swerdlow et al 2008.)
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