Photo by Logan Tuttle
A new study suggests children with acute lymphoblastic leukemia (ALL) are more likely to suffer early relapse if they live in high-poverty areas.
All of the children studied received the same treatment, and the rates of relapse were similar regardless of poverty level.
But early relapse was more common among children from poorer areas. These children also had a lower rate of 5-year overall survival, but the difference was not significant.
Kira Bona, MD, of Dana-Farber Cancer Institute in Boston, Massachusetts, and her colleagues reported these results in Pediatric Blood & Cancer.
The team examined outcomes for 575 children, ages 1 to 18, with newly diagnosed ALL who were treated on Dana-Farber Cancer Institute ALL Consortium Protocols at 7 major academic medical centers in the US between 2000 and 2010.
Using US Census Bureau criteria, the investigators defined high-poverty areas as zip codes where 20% or more of residents have incomes below the federal poverty level. For a family of 4, this translates to an annual income of $24,250 or less.
Dr Bona and her colleagues found the overall rates of relapse were similar between children from low-poverty areas and those from high-poverty areas.
However, the timing of relapse differed significantly. Ninety-two percent of children from high-poverty areas who relapsed suffered early relapse (less than 36 months after first achieving complete remission), while 48% of the other children who relapsed did so early (P=0.008).
The 5-year overall survival was 85% for children from high-poverty areas and 92% for children from low-poverty areas. This difference is statistically significant when considered on its own (P=0.02) but not when the analysis is adjusted for other factors (P=0.07).
Still, the investigators said this suggests a possible disparity in survival.
“These children are getting the same best possible care at well-resourced institutions from highly trained clinicians, and we’re still seeing disparities,” Dr Bona said. “In trying to improve cure rates, we, as a field, have focused almost exclusively on biology. If we want to move forward, we also have to look at social determinants.”
Next steps
Dr Bona and her colleagues are undertaking further research designed to delve deeper into the relationship between socioeconomic status and outcomes and to allow for the development of poverty-targeted interventions.
As part of a prospective trial for children with ALL, the researchers will investigate associations between disease outcomes and the socioeconomic status of patients’ families, using a targetable measure of socioeconomic status called material hardship (food, housing, and/or energy insecurity).
The researchers will also investigate possible mechanisms underlying the relationship between socioeconomic status and early relapse, including adherence to oral chemotherapy and delays or dose reductions in chemotherapy due to a child’s underlying health.
In another study, investigators will conduct in-depth interviews with patients’ families, probing their knowledge and experience to pinpoint factors that might explain the disparity in outcomes and identify factors that can be targeted with interventions.
“Doing these next 2 studies is incredibly important,” Dr Bona said. “This study told us that simply providing the current best treatment regimen is not good enough if our goal is to cure every child with cancer.”
“At the same time that we develop new drugs and new treatment protocols, we need to address social determinants of health. Findings from these next studies will help us develop specific interventions to address disparities in outcomes. That’s an amazing opportunity.”
