Patients With Down Syndrome Tend to Have Poorer Leukemia Outcomes

Patients with B-ALL who have Down syndrome tend to have poorer outcomes than their counterparts without Down syndrome, recent research showed.

Patients with B-cell acute lymphoblastic leukemia (B-ALL) who also have Down syndrome tend to have a higher rate of relapse and treatment-related deaths compared to their counterparts with ALL who do not have Down syndrome, according to recent research published in the Journal of Clinical Oncology.

The researchers analyzed data from four trials that included patients aged 30 years or younger with standard-risk or high-risk B-ALL. Overall, there were 743 patients with Down syndrome included, and 20,067 patients without Down syndrome.

Findings showed that patients with Down syndrome tended to have a higher frequency of minimal residual disease (MRD; small fragments of cancer that remain in the blood after treatment) of 0.01% or higher. Specifically, 30.8% and 21.5% of patients with and without Down syndrome, respectively, had MRD status of 0.01% or higher. This difference was also seen at the end of consolidation therapy — treatment intended to eradicate all cancer cells — in patients with high-risk disease, at 30% and 11%.

Patients with Down syndrome in both high-risk and standard-risk B-ALL groups tended to have poorer five-year event-free survival (EFS; time a patient lives without complications from cancer) and overall survival (OS; percentage of patients who are still alive after five years). Five-year EFS was 79.2% versus 87.5% for those with and without Down syndrome, respectively. Five-year OS was 86.8% and 93.6%.

Factors associated with inferior EFS in patients with Down syndrome were:

• Age 10 and older
• White blood cell count above 50 3 103/milliliter
• MRD at or above 0.01% after induction treatment

The researchers also discovered that patients with Down syndrome tended to have a higher five-year incidence of relapse than those without Down syndrome, at 11.5% compared with 9.1%; death during cancer remission (4.9% versus 1.7%); and induction death (3.4% versus 0.8%).

“Although the majority of relapses were late, post-relapse OS was dismal, suggesting the inability to tolerate intensive retrieval strategies,” the researchers wrote.

READ MORE:Mortality Risk Later in Life May Be Increased in Childhood Leukemia Survivors With Down Syndrome

While the researchers noted that certain differences in outcomes between patients with and without Down syndrome have decreased in recent years, outcomes are still not equitable. Not to mention, according to data published in The Lancet, children with Down syndrome have approximately 10 times the risk of developing B-ALL than children without Down syndrome.

“Our data demonstrate that disparities in EFS, OS and relapse have narrowed compared with earlier reports. This improvement is likely attributable to the efficacy of modern, intensified chemotherapy regimens, similar to the improvements observed in some other ALL subgroups,” the researchers wrote. “However, despite instituting DS-specific supportive care modifications, the composite of induction deaths and postinduction (treatment-related mortality) is 8.3% versus 2.5% for (Down syndrome) versus non-(Down syndrome) patients.”

In all trials reviewed, mucositis, infections and high blood sugar (hyperglycemia) were all higher in patients with Down syndrome. Meanwhile, in high-risk trials, seizures were more frequent in patients with Down syndrome (4.1% versus 1.8%).

“Novel approaches such as immunotherapies and targeted therapies hold particular promise to improve outcomes through enhanced efficacy and reduced toxicity in patients with (Down syndrome,” the researchers concluded.

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