In a nutshell
This study examined whether the presence of certain genetic changes had an impact on the rate of survival of children with chronic myeloid leukemia.
Some background
Chronic myeloid leukemia (CML) is a disease in which the bone marrow makes too many mature and immature white blood cells. CML is a slowly progressing blood and bone marrow disease that usually occurs during or after middle age, and rarely occurs in children.
Most people with CML have a classic genetic alteration (change) called the Philadelphia chromosome. This is a change in the t(9;22) gene. Some people have additional genetic changes. These are referred to as additional cytogenetic abnormalities (ACAs). Because of the rarity of CML in children, such abnormalities have not been investigated in a large group of children and adolescents with CML.
Methods & findings
This study involved 301 children with CML. Most of the children were found to have classic genetic changes associated with CML at diagnosis. 19 children (6.3%) had ACAs. Of these, 5 children (1.7%) had a different change in the t(9;22) gene, 13 children (4.3%) had ACAs, and 1 child had changes in both. Patients were followed for an average of 3.3 years.
268 children were treated with imatinib (Gleevec). Of these children with the classic genetic change, there was a 95% chance of being progression free at 3 years. This chance was 75% in children with a different t(9;22) change, and 100% for those with ACAs. The probability of 3-year overall survival (time from treatment until death from any cause) for children with the classic genetic change was 98%. It was 75% for those with a different t(9;22) change, and was 100% for those with ACAs.
The bottom line
This study showed that the presence of additional genetic changes in children with CML had no impact on their survival rates compared to children with the classic genetic changes alone.
The fine print
The number of patients in this study was small. More studies will be needed to confirm the results.
Published By :
Cancer
Date :
May 12, 2017