Chronic myeloid leukaemia (CML)

Overview:

• The majority of patients with this disease are older and die within 5 years of diagnosis
• Has a chronic phase (of 3-4 years duration) and an acute (or blastic) phase
• The blastic phase of CML is characterised by the development of acute leukaemia which may be:
• Myeloid (60%)
• Lymphoid (30%)
• Erythroid (10%), in origin

• The blastic phase is generally refractory to treatment, the median survival being <6 months

Clinical features:

Symptoms:

• Anaemia
• Night sweats
• Fever
• Weight loss
• Abdominal discomfort owing to splenic enlargement

Signs:

• Those of anaemia
• Splenomegaly

Investigations:

FBC:

• Hb normal or low
• Raised WCC (characteristically with the whole spectrum of myeloid precursors)

• Platelets normal, low or raised

Bone marrow aspirate:

• Shows a hypercellular marrow with an increase in myeloid precursors
• The Philadelphia (Ph) chromosome is present in most patients

Treatment:

Interferon (IFN) therapy:

• Induces haematological remission in most patients
• Induces cytogenetic remission in ~10% of patients
• Problems:
• Has to be given subcutaneously
• Side-effects can be intolerable (mainly fatigue)

Myeloablative therapy supported by allogeneic BMT:

• May be curative
• Limited by donor availability and the morbidity/mortality associated with the treatment itself