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Chapter 17 Acute lymphoblastic leukaemia / 233

Allogeneic SCT is playing an increasingly impor- gene. As such, allogeneic SCT is recommended
tant role for ALL in adults and many patients are wherever possible once remission has been obtained.
treated with this if a suitable sibling or matched Second generation TKIs are now in use but their
unrelated donor is available. long - term value is uncertain at present.

Treatment of BCR - ABL 1 p ositive ALL Prognosis

The introduction of imatinib and other tyrosine There is a great variation in the chance of individual

kinase inhibitors (TKIs) has transformed the man- patients achieving a long - term cure based on a
agement of patients with BCR - ABL1 + (Ph + ) ALL. number of biological variables (Table 17.4 ).
Imatinib may be used alone or in combination with Approximately 25% of children relapse after fi rst -
chemotherapy and is able to obtain remission of the line therapy and need further treatment but overall
disease in most patients. However, relapse is very 85% of children can expect to be cured. Th e cure

common because of the appearance of resistant sub- rate in adults drops significantly to less than 5%
clones containing mutations in the BCR - ABL1 over the age of 70 years.

■ Acute lymphoblastic leukaemia (ALL) is have a good prognosis whereas

caused by an accumulation of hypodiploid cases ( < 44 chromosomes)
lymphoblasts in the bone marrow. It is the carry a poor prognosis.
most common malignant disease of ■ Treatment protocols for ALL are extremely SUMMARY

childhood – 75% of cases occur before the complex and usually have four
age of 6 years. Eighty - fi ve per cent of components – remission induction,
cases are of B - cell lineage with the rest intensifi cation, CNS - directed therapy and
being of T - cell lineage. maintenance.
■ The fi rst genetic mutation occurs in many ■ Treatment is risk adjusted to reduce the

cases in utero , with a secondary genetic treatment given to patients with good
event occurring later in childhood, possibly prognosis. This is based on age, gender,
as a reaction to an infection. white cell count and cytogenetics at
■ The clinical presentation is with the presentation.

features of bone marrow failure (anaemia, ■ Small numbers of tumour cells may
infection and bleeding) together with sometimes be detected by FACS or
symptoms of tissue infi ltration by tumour molecular analysis even when the blood
cells, leading to bone pain or swollen and bone marrow appear to be clear of
lymph nodes. leukaemia. This minimal residual disease

■ Diagnosis is by examination of blood and has prognostic signifi cance and is used in

bone marrow. Important tests include planning therapy.

microscopic examination of the tumour ■ If relapse occurs during chemotherapy the
cells, immunophenotyping and genetic outlook is poor but if it happens after years
analysis. off all treatment the outlook is better.

■ ALL is subclassifi ed according to the Further chemotherapy and allogeneic SCT
underlying genetic defect and a wide should be considered.
variety of genetic lesions are seen. The ■ Overall, 85% of children can now expect to

number of chromosomes in the tumour cell be cured. The cure rate in adults drops
has prognostic importance: Hyperdiploid signifi cantly to less than 5% over the age
cells have > 50 chromosomes and generally of 70 years.
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