Prognosis of ALL

The following factors are associated with prognosis in ALL patients:

• age at diagnosis is considered to be a strong prognostic factor. According to a study carried out at children’s Research Hospital with 847 children with ALL:
• children between the age 1 to 9 had a better outcome than infants or adolescents. The 5 year event free survival estimates were (1)
  • for children aged 1-9 - 88%
  • adolescents aged 10–15 years - 73%
  • older than 15 years - 69%
  • babies younger than 12 months - 44%
• prognosis was poor especially for babies younger than 6 months
  
  
• age-specific mortality rates rise steadily from birth and more steeply from around age 45-49. The highest rates are in the 85 to 89 age group for males and the 90+ age group for females (2)

Open Image in Modal

• increased leukocyte count presents with poor prognostic outcome.
• this is especially true in patients with B-cell precursor disease
• in T cell ALL, a count of more than 100x109/L is associated with an increased risk of relapse in the CNS
• high risk of early complications are seen in patients with extreme hyperleucocytosis (>400x109/L) e.g - CNS haemorrhage and pulmonary and neurological events due to leucostasis (1)
• chromosomal abnormality
• poorer outcome is also associated with Philadelphia chromosome, t(4;11) with MLL-AF4 fusion, and hypodiploidy (<44 chromosomes per leukaemic cell)
• favourable prognosis was seen in patients with hyperdiploidy (>50 chromosomes), TEL-AML1fusion, and trisomy 4, 10, and 17

Children respond well to treatment:

• 95% achieve complete remission
• 50-60% of whom are cured with postremission chemotherapy

Fewer advances have been achieved in adults:

• 80% achieve complete remission
• about 35% achieve long-term disease-free survival

The poorer response seen in adults may reflect undertreatment because of the increased risk of drug toxicity.

Reference:

• (1) Pui CH, Robison LL, Look AT. Acute lymphoblastic leukaemia. Lancet. 2008;371(9617):1030-43.
• (2) CRUK. Acute lymphoblastic leukaemia (ALL) mortality statistics (Accessed 28/5/19)