Unlike other types of cancer, there is no staging system for childhood acute lymphoblastic leukemia. Doctors plan the treatment based on factors involving age (infants younger than 12 months and children age ten and older), white blood cell counts (children with very high white blood cell counts need intensive treatments), genetic abnormalities in the leukemia cells, response to early treatment, and immunophenotyping.
Classification of Childhood Acute Lymphoblastic leukemia
There is no staging system for childhood Acute lymphoblastic leukemia, unlike other types of cancer. However, several factors help doctors choose the best treatment plan and predict the chances of recurrence after treatment. Doctors plan the treatment based on these factors
Infants younger than 12 months and children aged ten and older need more intensive treatments.
White blood cell counts
Children with very high white blood cell counts need more intensive treatments. Commonly, white blood cell counts are labelled as very high if they are more than 50,000 per microliter (microL).
Genetic abnormalities in the leukaemia cells
Abnormal numbers of chromosomes, abnormal structural changes in a chromosome, or specific molecular genetic changes in the chromosomes of leukemia cells may affect outcome and treatment 1. It is noteworthy that the genetic changes referred to here are changes in the genes of the leukemia cells; not all the cells in a child’s body – most children with leukemia have completely normal genes.
Response to early treatment
How well the treatment works in the first 1 to 4 weeks may predict the overall response to treatment. This will be determined by regularly examining the child’s blood or bone marrow. Recent studies showed that some children might need more intense treatment to enhance the chance of a cure. This involves children whose cancer is not responding well to the first treatments or those having high levels of residual leukaemia cells (cells remaining after treatment) at the end of the treatment period called remission induction.
This test shows the types and amounts of proteins made or expressed by the leukaemia cells. Knowing if the cancer cells express the proteins similar to normal white blood cells called T-cells or B-cells will help doctors plan appropriate treatment 2. It is also helpful to help predict how well treatment will work.
- 1.Ross ME, Zhou X, Song G, et al. Classification of pediatric acute lymphoblastic leukemia by gene expression profiling. Blood. Published online October 15, 2003:2951-2959. doi:10.1182/blood-2003-01-0338
- 2.Nakazawa S, Saito M, Okazaki T, et al. Immunological Classification of Childhood Acute Lymphoblastic Leukemia. Pediatr Int. Published online August 1991:507-521. doi:10.1111/j.1442-200x.1991.tb02580.x