Acute Lymphoblastic Leukaemia Flashcards
What is acute lymphoblastic leukaemia?
A type of cancer that starts from lymphocytes in the bone marrow
When does acute lymphoblastic leukaemia present?
It can present in adults and children, but is more often diagnosed in younger people
What % of leukaemias in children does acute lymphoblastic leukaemia account for?
80%
What is the peak age of onset of acute lymphoblastic leukaemia?
2-5 years
What kind of cells are the malignant cells in acute lymphoblastic leukaemia?
Lymphoid precursor cells that are arrested in an early stage of development
What causes the arrest of development of lymphoid precursor cells in ALL?
An abnormal expression of genes
What can the abnormal expression of genes result from in ALL?
Often a result of chromosomal translocations or abnormalities in chromosome number
Why is there a reduction in normal blood cells in ALL?
Because the lymphoblasts replace the normal marrow elements, resulting in a decreased production of normal blood cells
What is the result in the reduced production of normal blood cells in ALL?
- Anaemia
- Thrombocytopenia
- Neutropenia
Where else in the body can lymphoblasts infiltrate in ALL?
Outside the marrow, particularly in the liver, spleen, and lymph nodes
What are the risk factors for ALL?
- Genetic syndromes
- Identical twin with ALL
- Significant radiation exposure
- Prior chemotherapy
Give 2 examples of genetic syndromes that increase the risk of ALL
- Down syndrome
- Li-Fraumeni syndrome
Describe the onset of presentation of ALL
In most children it presents insidiously over several weeks, however in some children the illness progresses very quickly
What do the clinical signs of ALL result from?
Disseminated disease and systemic ill-health
What causes systemic ill-health in ALL?
Infiltration of bone marrow or other organ with leukaemic blast cells
What clinical features result from bone marrow infiltration in ALL?
- Anaemia
- Neutropenia
- Thrombocytopenia
- Bone pain
What symptoms might result from anaemia in ALL?
- Pallor
- Lethargy
What might neutropenia lead to in ALL?
Infection
What might thrombocytopenia lead to in ALL?
- Bruising
- Petechiae
- Nose bleeds
What clinical features result from reticulo-endothelial infiltration in ALL?
- Hepatosplenomegaly
- Lymphadenopathy and superior mediastinal obstruction
What clinical features result from CNS infiltration in ALL?
- Headaches
- Vomiting
- Nerve palsies
What clinical features result from testicular infiltration in ALL?
Testicular enlargement
What general symptoms may be present in ALL?
- Malaise
- Anorexia
What investigations should be done in ALL?
- FBC
- Bone marrow examiantion
- Clotting screen
What might be found on FBC in ALL?
- Low haemoglobin
- Thrombocytopenia
- Evidence of circulating leukaemic blast cells
What is the role of bone marrow examination in ALL?
Essential to confirm diagnosis, and to identify immunological cytogenic characteristics which give useful prognostic information
Why is it important to do a clotting screen in ALL?
About 10% of patients have DIC at the time of diagnosis, which can present with haemorrhagic or thrombotic complications
What are the differential diagnoses of ALL?
- Infectious mononucleosis
- Acute myeloid leukaemia
- Lymphoblastic lymphoma
- Aplastic anaemia
What are the categories in management of ALL?
- Induction of remission
- Intensification
- Management of CNS involvement
- Continuation of therapy
- Treatment of relapse
What does remission imply in ALL?
Eradication of the leukaemic blasts, and restoration of normal marrow function
How is induction of remission achieved in ALL?
Combination chemotherapy including steroids is given
What rates of remission are achieved using current induction treatment schedules?
95%
What is involved in intensification of treatment in ALL?
A block of intensive chemotherapy can be given
What is the purpose of intensification of treatment in ALL?
It improves cure rates
What is the problem with intensification of treatment in ALL?
Increased toxicity
What is the problem with traditional chemotherapy in the management of CNS involvement with ALL?
Cytotoxic drugs penetrate poorly into the CNS, and so leukaemic cells at this sit may survive effective systemic treatment
What is the result of traditional chemotherapy not being very good for the management of CNS involvement?
Intrathecal chemotherapy is used to prevent CNS relapse
What should be done with patients who have evidence of CNS disease at diagnosis?
They should receive additional doses of intrathecal chemotherapy during induction
What is involved in continuation of therapy in ALL?
Chemotherapy of modest intensity is continued for a relatively long time, up to 3 years from diagnosis
What additional medication (to chemotherapy) is given during continuation of therapy for ALL?
Co-trimoxazole
What is the purpose of co-trimoxazole given in continuation of therapy for ALL?
It is given routinely as prophylaxis to prevent Pneumocystitis pneumonia
What is involved in the treatment of relapse in ALL?
High-dose chemotherapy with or without total body irradiation, followed by bone marrow transplantation
What are the complications of ALL?
- Infection
- Tumour lysis syndrome
