Early Relapse More Likely in Children With ALL From High Poverty Areas

Although a child’s socioeconomic status did not seem to significantly affect 5-year overall survival of acute lymphoblastic leukemia (ALL), those children who were from high-poverty areas experienced early relapse compared with children who were from low-poverty areas, according to the results of a single-center study published in Pediatric Blood & Cancer.

“These children are getting the same best possible care at well-resourced institutions from highly trained clinicians, and we’re still seeing disparities,” said lead researcher Kira Bona, MD, MPH, a pediatric oncologist at Dana-Farber/Boston Children’s, in a press release. “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.”

In the study, Bona and colleagues examined all children aged 1 to 18 treated for newly diagnosed ALL on consecutive phase III Dana-Farber Institute ALL Consortium Protocols from 2000 and 2010. The researchers were trying to determine if a relationship exists between a patient’s socioeconomic status and overall or event-free survival.

The study included 575 patients drawn from the protocols who had zip code information available. Using these zip codes, the researchers categorized the children into high- or low-poverty areas using US Census data. Fifteen percent of the patients were considered to be from high-poverty areas.

The researchers identified no significant differences between high- and low-poverty area children for age, presenting white blood cell count, or immunophenotype.

Initial analysis showed that children in low-poverty areas had significantly improved 5-year overall survival (92% vs 85%) compared with the children from high-poverty areas. However, after the data were adjusted for immunophenotype, age, and white blood cell count, a child’s poverty status remained only “marginally significant” (P = .07), the researchers wrote.

Relapse occurred in 14% of children from a high-poverty area and 11% of children from a low-poverty area. Children from the high-poverty areas tended to experience earlier relapse as compared with children from the low-poverty areas. Within 16 months, 92% of children from the high-poverty area had relapsed compared with 48% of children from low-poverty areas (P = .008).

According to the researchers, there are many possible reasons why the children from high-poverty areas may experience earlier relapse.

“One possible mechanism is that of inferior underlying health status for children from high-poverty areas,” the researchers wrote. “US children from lower socioeconomic status households are more likely to be in fair or poor health, experience hospitalization, infectious disease, poor growth, and worse health-related quality of life.”

In addition, the researchers wrote that “given that time to relapse is a known prognostic factor in children with relapsed ALL, with earlier relapses being harder to salvage, it seems likely that the trend toward inferior survival we observed in high-poverty children was related to the higher rate of earlier relapses in this population.”